The Ultimate Guide to CBD: Everything You Need to Know

You’ve probably heard of CBD oil. Celebrities and athletes are endorsing it, and the media is constantly talking about it. More importantly, millions worldwide use CBD oil and other CBD products to help with pain, anxiety, sleep problems, and many other common symptoms and disorders.

But what is CBD exactly? Does it work? What does science say about its effects? Is it worth the hype? This comprehensive, evidence-based guide will answer these and many other questions about CBD. We’re going to go in-depth and look at evidence from 150+ peer-reviewed research studies.

Here’s everything you need to know about CBD.

What is CBD?

Cannabidiol (CBD) is a naturally occurring substance in cannabis. It’s one of more than 120 compounds called phytocannabinoids (1). Most of the effects of cannabis — both recreational and medicinal — come from these natural compounds. CBD has been consumed for millenia as part of whole-plant cannabis.

You’ve probably heard of tetrahydrocannabinol (THC) — the phytocannabinoid responsible for the intoxicating effects of marijuana.

Unlike THC, CBD is non-intoxicating, which means it doesn’t get you high. You can take CBD to get the benefits of cannabis without worrying about the mind-altering effects.

CBD has been shown to have an exceptionally wide range of potential health benefits. It’s not difficult to see why so many people are using it.

Did you know? Many people incorrectly believe that CBD is non-psychoactive. By definition, a psychoactive substance is anything that affects brain function. Since CBD has anti-anxiety, antidepressant, and antipsychotic effects, it is indeed psychoactive (2). It just doesn’t intoxicating you the way THC does.

Where Does CBD Come From?

There are two types of cannabis: marijuana and hemp. Marijuana contains a lot of THC but little CBD. Hemp is the opposite: it’s low in THC (no more than 0.3%) but high in CBD.

CBD products are almost always sourced from hemp because it’s cheaper and doesn’t contain enough THC to cause intoxication. That’s also why hemp is legal in the US and many other countries.

CBD vs. THC At a Glance

	CBD	THC
Source	Usually sourced from hemp (low THC, high CBD cannabis)	Usually sourced from marijuana (high THC, low CBD cannabis)
Intoxication	Non-intoxicating	Makes you high
Legality	Legal in the US and many other countries	Illegal in most countries and US states
Uses	Dietary supplement, antiepileptic drug	Recreational drug and medicine
Main Shared Benefits	Pain, inflammation, nausea relief	Pain, inflammation, nausea relief
Main Unique Benefits	Anxiety relief, anticonvulsant	Lowers eye pressure, stimulates appetite (3)
Common Side Effects	Tiredness, drowsiness, diarrhea, dry mouth	Similar to CBD, plus mind-altering effects such as memory impairment, anxiety, paranoia
Most Common Products	CBD oil, gummies, capsules, topicals, prescription drugs (Epidiolex)	Marijuana and THC-only prescription drugs

Hemp Oil vs. CBD Oil: Not the Same Thing

Although they’re both sourced from hemp, hemp oil and CBD oil are not the same.

The key difference is that hemp oil comes from hemp seeds, which do not contain any cannabinoids (unless contaminated during the manufacturing process).

Better known as hemp seed oil, it’s mostly used as a healthy oil rich in essential fatty acids and other nutrients. It’s also sometimes taken as an oral or topical dietary supplement.

Meanwhile, CBD oil comes from the flowers and other above-ground parts of the hemp plant. These parts of hemp are covered in hair-like structures called trichomes, which contain CBD and other cannabinoids (4). 

The easiest way to tell apart hemp oil and CBD oil is the ingredients list. Hemp oil will be listed as “hemp seed oil,” whereas a CBD oil will say something like “CBD,” “cannabidiol,” or “hemp extract” in addition to other ingredients. 

It’s even better if you check third-party tests to confirm the presence of CBD.

CBD Legality

Hemp-derived CBD products became legal in the United States thanks to the 2018 Farm Bill. This bill made hemp into a legal, agricultural commodity that can be grown by farmers, which means it can also be used to make CBD products.

Having said that, there are some stipulations. For example, hemp can only contain 0.3% or less THC. Also, individual states have the power to regulate hemp and by extension hemp-derived CBD products in their own way. While most align with federal policy, a few have more restrictive laws.

CBD also became legal in Canada in 2018 in Thailand in 2022 when these two countries legalized cannabis.

Meanwhile, the legal status of CBD in other countries varies drastically. Generally speaking, it can fall into one of four categories:

1. Legal
2. Gray area (unclear)
3. Medical-only use (by prescription)
4. Completely banned

As a rough guideline, CBD is:

• Legal in most European countries
• Mostly restricted to medical use in South America, Australia, and New Zealand
• Banned in Africa (except South Africa) and the Middle East
• Ranges from illegal to legal for other Asian countries

CBD Benefits

According to decades of research studies, CBD has been shown to have many beneficial effects, including: (1)

• Antioxidant
• Anti-inflammatory
• Antiemetic (anti-nausea/vomiting)
• Antidepressant
• Anxiolytic (anxiety relief)
• Antipsychotic
• Analgesic and antinociceptive (pain relief)
• Neuroprotective
• Anticonvulsant
• Anticancer (2)
• Antibacterial
• Immunomodulatory/immunosupressive
• Anti-addictive properties

It’s no surprise that CBD may help with a wide range of symptoms and conditions. Here’s a closer look at CBD’s potential health benefits.

Epilepsy and Seizures

There is strong clinical research evidence that CBD can help with epileptic seizures, particularly the treatment-resistant types that typically occur in children.

The evidence is so compelling that the CBD-based drug Epidiolex is approved in the US and Europe for the treatment of Lennox-Gastaut syndrome (LGS), Dravet syndrome (DS), and tuberous sclerosis complex (TSC), three rare and severe types of epilepsy (51).

For example, a 2018 review of 36 studies, most of which looked at children with rare and severe types of epilepsy, concluded that CBD reduced the number of seizures and stopped them entirely in some people (50). Similarly, a 2023 review of 6 randomized controlled trials (RCTs), the gold standard of clinical research, concluded that CBD was highly effective at treating seizures caused by LGS, DS, and TSC (1).

Anxiety Disorders

Relieving anxiety is one of the most common uses of CBD. It’s also backed by some of the strongest research evidence (after CBD’s anti-epileptic effects):

• A 2011 Brazilian study found that CBD capsules reduced anxiety caused by public speaking in people with social anxiety disorder (SAD) (52)
• A 2019 Japanese study found that CBD oil reduced anxiety in teenagers with SAD (53)
• A 2022 Australian study of 31 people with treatment-resistant anxiety disorders found that CBD reduced anxiety severity and depressive symptoms (1)
• A 2022 study of 14 people with moderate-to-severe anxiety found that full-spectrum CBD oil improved anxiety as well as mood, sleep, and quality of life (1)
• A 2023 study of 198 people with anxiety disorders reported “improved anxiety, depression, fatigue, and the ability to participate in social activities” after using medical cannabis, particularly CBD-only preparations (1)
• A 2019 Colorado study found that CBD reduced the symptoms of post-traumatic stress disorder (PTSD), another type of anxiety disorder (54)

All in all, researchers believe that CBD has potential in the treatment of all sorts of anxiety disorders, including SAD, generalized anxiety disorder (GAD), panic disorder (PD), PTSD, and obsessive-compulsive disorder (OCD) (1).

Depression

Alongside anxiety, depression is the most common mental disorder worldwide. Early studies suggest that CBD has antidepressant effects (57). 

Unfortunately, there aren’t any clinical studies of CBD where depression was the main focus. For now, the only evidence we have is from studies of people with anxiety disorders, where mood symptoms were evaluated as a secondary measure:

• One 2022 study of 14 adults with moderate-to-severe anxiety reported that CBD oil improved mood as a secondary outcome (1)
• A similar 2022 Australian study in adults with treatment-resistant anxiety reported that CBD improved depressive symptoms (1)
• A 2023 study of 198 people with anxiety disorders reported improvements in depression (1)
• A 2018 study of 20 people suffering from cannabis use disorder found that CBD improved depressive symptoms (1)

While these findings look promising, they need to be replicated in high-quality clinical trials before we have solid evidence that CBD can help with depression. As concluded by a 2022 review paper, “there is insufficient evidence to recommend cannabidiol as a treatment for mood disorders, and high-quality clinical trials are urgently needed.” (1)

Pain and Inflammation

Cannabis, which contains both THC and CBD, has been used to treat pain and inflammation for millenia (59). Today, chronic pain relief remains the most common indication for using cannabis and cannabis-based medicine (1).

Although these effects have been usually attributed to THC, recent research has demonstrated that CBD also has anti-inflammatory and analgesic (pain-relieving) effects.

Here’s a look at the key research findings:

• A 2020 study of 97 chronic pain sufferers taking opiod painkillers found that full-spectrum CBD oil reduced opioid use. After using the CBD oil for 8 weeks, over 50% of the 97 study participants lowered or stopped using opioid painkillers and 94% said CBD improved their quality of life (63).
• Another 2020 study found that topical CBD oil improved neuropathic pain in 29 people (64)

Additionally, multiple chronic pain patient surveys have reported promising results:

• A 2020 survey of 400 New Zealand patients found that CBD oil significantly improved chronic pain (1)
• A 2020 survey of 58 palliative care patients in Florida found that half of those using CBD reported reduced pain (1)
• A 2021 survey of 253 chronic pain sufferers reported that out of those taking CBD, 59% reported improved pain and 68% lowered their pain medication use (1)
• Another 2021 survey of 2701 people with fibromyalgia and other chronic pain conditions reported slight to serious improvements in pain and other symptoms (1)

Tying everything together, a 2023 review paper concluded that “…CBD seems to be a promising strategy to overcome the lack of efficacy of conventional treatment for chronic pain…” (1)

That said, more high-quality research is needed. For now, the best evidence is restricted to studies that use whole-plant cannabis or Sativex, a 1:1 THC:CBD drug (1). This makes it difficult to say how much of the pain relief comes from CBD compared to THC and other cannabis compounds.

Arthritis

Arthritis as another common reason people turn to CBD. That’s not surprising since it involves both inflammation and pain, two common symptoms that CBD can help with. Early findings of using CBD for arthritis are promising:

• In a 2022 RTC study of 18 people with thumb basal joint arthritis, topical CBD improved pain and disability (1)
• A 2022 survey of 428 arthritis patients who used CBD found that 83% experienced less pain and 66% improved physical function, with an average 44% reduction in pain. The majority (60.5%) also reduced or stopped taking other pain medications (1).

But again, more high-quality studies are needed before we can say anything conclusive. For now, most of the evidence comes from studies of rats and mice.

Sleep Disorders

Another common issue people use CBD products for is difficulty sleeping. There’s growing evidence that CBD can help with sleep:

• A 2023 RCT study looking at the effects of CBD in 1793 adults with sleep problems found that 15 mg CBD was as effective as 5 mg melatonin at improving sleep quality (1)
• A 2023 pilot study of six insomniacs found that pure CBD (300 mg) combined with eight calming terpenes improved restorative sleep (1)
• In a 2019 study of people taking opioid painkillers, full-spectrum CBD oil improved sleep quality as one of the secondary measures (1)
• In a 2022 study of 14 adults with moderate-to-severe anxiety, CBD oil improved sleep as one of the secondary outcomes (1)
• In a 2019 study of 53 children with autism spectrum disorder (ASD), CBD improved sleep in 71.4% (as a secondary measure) (1)
• A 2011 study of 33 people suffering from REM sleep behaviour disorder (RBD) found that 300 mg of CBD improved sleep satisfaction (1)

These findings highlight that CBD can help both directly and indirectly, by countearing anxiety, pain, stress, depression, and other issues that cause sleeping problems.

Finally, a 2023 review on the use of CBD for insomnia concluded that “”…CBD alone or with equal quantities of THC may be beneficial in alleviating the symptoms of insomnia.” (1)

Neurodegenerative Disorders

Neurodegeneration is the breakdown of the function and structure of neurons. It plays a central role in Alzheimer’s, Parkinson’s, Huntington’s, and other incurable neurological diseases. 

While most of the evidence is restricted to animal investigations, a growing number of human studies are showing that CBD has neuroprotective effects:

• In a 2014 RCT study, CBD improved well-being and quality of life in 21 Parkinson’s disease (PD) sufferers (72)
• In a 2008 study, CBD improved psychosis in six people with PD (73)
• A 2019 pilot study of ten women with severe dementia found that cannabis oil containing a 2:1 ratio of CBD to THC improved behavior, reduced daily care needs, and allowed half of the patients to reduce or stop taking other prescription drugs (74)
• In a 2020 study of 20 healthy volunteers, CBD improved cerebral blood flow to parts of the brain involved in memory processing, suggesting that it may help with Alzheimer’s and other conditions linked to issues with memories, like PTSD (1)

A 2023 review of CBD’s neuroprotective effects concluded that “A long history of using CBD, extensive experimental evidence, a multitude of anecdotal clinical studies, and a few descriptive clinical studies hint at the potential clinical value of CBD in the treatment of neurological disorders” (1)

Blood Pressure & Cardiovascular Health

The application of CBD and other cannabinoids for heart and cardiovascular health is a relatively new area of research. Early studies suggest that CBD can lower blood pressure and have other beneficial effects on the cardiovascular system:

• A 2017 study demonstrated that CBD can lower resting blood pressure and reduce the rise in blood pressure caused by stress in healthy adults (77)
• A 2023 study of 16 adults with untreated hypertension found that CBD reduced arterial stiffness and blood pressure (1)
• A 2007 study found that CBD protected coronary artery cells from damage caused by high blood sugar (78)
• A 2010 animal study found that CBD had a positive effect on cardiomyopathy, a cardiovascular complication of diabetes (79)
• A 2017 review of multiple animal studies concluded that CBD can increase blood flow during a stroke and reduce stress-related increases in blood pressure and heart rate (80)
• A 2007 study reported that CBD protected the hearts of mice against damage caused by myocardial ischemia (reduced heart blood flow) (81)

As summarized by a 2020 review, CBD has been shown to have many positive effects in animal studies of heart disease, stroke, cardiovascular complications of diabetes, and other cardiovascular conditions (1). But further human studies are needed.

Skin Disorders

Another area in which CBD holds much promise is skin conditions. This isn’t all that surprising since there’s mounting evidence that the endocannabinoid system plays a key role in skin health and its dysfunction is linked to itching, acne, eczema, psoriasis, and many other skin issues (82).

Although most of the evidence is limited to animal and petri dish studies, early human findings are promising:

• In a 2019 study of 20 people with psoriasis and eczema, a CBD-infused ointment improved psoriasis symptoms, scarring, as well as hydration, elasticity, and other measures of skin health (84).
• A 2021 observational study of 14 people with atopic dermatitis found that 1% CBD gel reduced symptom severity, including itchiness (1)
• A 2023 RCT study of 69 subjects with recurrent canker sores found that topical 0.1% CBD reduced ulcer size and accelerated healing without side effects (1)
• A 2022 study of 10 people with skin imperfections (like pores and wrinkles) found that thhe combination of retinol and CBD improved facial skin quality, including the reduction of visible pores, dehydration, surface roughness, and wrinkles (1)

Acording to a 2023 review paper, CBD has the potential to help with “ATD, psoriasis, acne, epidermolysis bullosa, systemic sclerosis, seborrheic dermatitis, scalp psoriasis, androgenetic alopecia and melanoma leading to better outcomes and improved patient quality of life.” (1) However, further clinical studies are needed.

Digestive Disorders

CBD has been shown to help with some digestive symptoms such as nausea, and may even have potential in treating chronic digestive disorders such as inflammatory bowel disease (IBD).

One 2018 RCT study looked at whether CBD can have a positive effect on ulcerative colitis, one of the two main kinds of IBD. Patients were given placebo or CBD-rich cannabis extract. Only the CBD group saw an improvement in symptoms and quality of life (87).

A similar 2021 RCT study looked at the effects of cannabis oil with a 4:1 ratio of CBD to THC in 56 patients with Crohn’s disease, the second type of IBD. They experienced significant improvements in quality of life (1).

Cancer

Cannabinoids are already utilized for cancer treatment. In particular, many cancer patients use marijuana and pure THC drugs to ease chronic pain, stimulate appetite, and reduce chemotherapy-induced nausea (90).

CBD can offer similar benefits. For example, one of the only human studies of CBD for cancer looked at the effects of pure THC and CBD in patients with severe, treatment-resistant cancer pain.

THC-only treatment had no significant effect, whereas the combination of CBD and THC reduced pain by 30% or more in 43% of the study participants (92).

On top of that, numerous animal and petri dish studies have reported beneficial effects:

• In a 2014 mouse study, CBD reduced pain caused by Paclitaxel, a chemotherapy medication (93)
• In a 2006 study, CBD reduced breast cancer tumor growth better than four other cannabinoids (94)
• Several studies have reported that CBD can promote the death of leukemia and breast cancer cells (95, 96)
• A 2007 study found that CBD inhibited aggressive breast cancer cells (97)
• Several studies have shown that CBD can make it harder for brain, lung, cervical, and other types of cancer to spread (migrate) to other parts of the body (98, 99)
• A 2012 study reported that CBD helped prevent colon cancer in mice (100)
• CBD can enhance the effects of chemotherapy drugs. In one 2018 study, CBD given alongside the cancer medication gemcitabine enhanced the survival of mice by almost three times compared to gemcitabine on its own (101).
• IN a 2018 study, CBD suppressed the release of exosomes and microvesicles (EMV), molecules that play a role in cancer (102)

These findings are quite promising and suggest multiple ways through which CBD can help with cancer. Having said that, they need to be replicated in human studies.

As concluded by a 2022 review paper, “Overall, the current study supports the notion that CBD can offer positive outcomes in cancer treatment. Future research in the area of CBD and cancer should aim to examine the efficacy and safety of CBD in human clinical trials…” (1)

Drug Addiction 

One of the most promising yet the least explored uses of CBD is the treatment of drug addiction. Research indicates that CBD can help reduce drug cravings and withdrawal symptoms, helping people quit a wide variety of addictive substances:

• In a 2013 study, 24 smokers used a CBD inhaler for a week. Compared to placebo, the CBD group smoked 40% fewer cigarettes, and some continued to smoke less after the study ended (103).
• A 2018 study found that a single 800 mg dose of CBD reduced the prominence and attractiveness of cigarette cues in smokers who have abstained from smoking overnight (1)
• A 2023 study of 20 nicotine vape users found that oral CBD reduced nicotine withdrawal and anxiety after a 4-hour abstinence period (1)
• In a 2010 study of cannabis addiction, smoking strains high in CBD was associated with reduced cannabis dependence (104)
• A 2020 RCT study of 48 people with cannabis use disorder found that oral CBD led to reduced cannabis consumption (1)
• In a 2019 RCT study of opioid addiction, people addicted to heroin had reduced cravings when taking CBD for 3 days, with the effects persisting for another week (105)
• A 2021 study of people who drink and use cannabis reported that those who smoked high-CBD strains were more likely to drink less alcohol compared to 1:1 or high-THC strains (1)

CBD holds so much promise in tackling drug addiction that respected American neuroscientist Yasmin Hurd believes that it could play a decisive role in combating the opioid crisis caused by the misuse of prescription and non-prescription opioids (107). 

The opioid epidemic leads to tens of thousands of overdose deaths and related issues every year in the United States, Canada, and several other countries. 

Diabetes

Early research indicates that CBD can help with diabetes and its complications:

• A 2022 RCT study of 50 people with type 2 diabetes found that a 10:1 CBD:THC sublingual (under-the-tongue) spray improved lipid profile (cholesterol, triglycerides, LDL-C) and glucose tolerance (1)
• A 2023 RCT study of 44 people suffering from idiopathic or diabetic gastroparesis (a complication of diabetes) reported symptom relief (1)

Additionally, animal studies have shown that CBD can:

• Prevent the development of type 1 diabetes (108)
• Help with numerous diabetic complications, including diabetic cardiomyopathy, retinopathy, and neuropathy (1)

As concluded by a 2023 review paper, “…CBD is of great value in the treatment of diabetes and its complications…” (1). Still, more human studies are needed before we fully understand CBD’s antidiabetic potential.

Migraines

Cannabis has a long history of use for migraines. Although CBD has yet to be examined in clinical trials for migraine, there is some evidence that it may be beneficial.

For example, a 2023 study in mice found that CBD reached some parts of the brain involved in migraine pain and reduced some inflammatory and pain-related processes involved in migraines (1)

Most importantly, there’s growing evidence that clinical endocannabinoid deficiency — a condition where your endocannabinoid system is not functioning properly — may be the cause behind migraines, fibromyalgia, irritable bowel syndrome, and other difficult-to-treat disorders (112).

Since CBD can increase endocannabinoid levels it may be able to help correct this deficiency and have a positive effect on migraines and other conditions as a result. However, this remains theoretical and proper research is needed.

Psychosis

CBD may also help with psychosis, which can occur in schizophrenia and other mental disorders:

• In one 2012 study, CBD improved psychosis in schizophrenia patients as effectively as the prescription medication amisulpride. However, it did so with fewer side effects (113).
• Another 2017 RCT study of 88 people with schizophrenia looked at the effect of adding CBD to standard medication. Compared to placebo, the CBD group had improved symptoms and cognitive function (114).
• A 2021 review paper concluded that CBD can improve psychosis caused by both THC and schizophrenia (1)

Autism

There’s also growing evidence that CBD may have multiple benefits for children and adults with autism spectrum disorder (ASD). Here’s a look at the most notable findings:

• One 2019 study found that CBD-enriched cannabis extract (75:1 ratio of CBD to THC) improved multiple symptom categories in 18 children and adolescents, including attention-deficit hyperactivity disorder (ADHD), behavioural disorders, seizures, sleeping problems, and motor, autonomy, communication, socialization, and cognitive deficits (116).
• In another 2019 study, CBD treatment improved behavioral issues in children with autism (117).
• Another 2019 study reported on the benefits of CBD-rich cannabis extract (30% CBD, 1.5% THC) in 188 children with autism, with most participants having a moderate-to-significant improvement in symptoms that included seizures, depression, and restlessness (118).
• A 2022 RCT study in 60 children with ASD found that CBD-rich cannabis extract improved social interaction, anxiety, concentration, and other measures (1)
• A 2023 study of 15 children with ASD found that CBD alongside low-dose THC improved social cognition (1)

Workout Benefits

CBD has many potential exercise & sports benefits, particularly for recovery. Research suggests that CBD can help athletes by: (119)

1. Speeding up muscle recovery and improving delayed-onset muscle soreness (DOMS) through its anti-inflammatory effects
2. Relieving pain from overuse, injuries, and other causes
3. Protecting against concussions and other forms of brain trauma, which is common in contact sports
4. Supporting healthy sleep, which is needed for optimal recovery
5. Supporting bone and cardiovascular health
6. Easing muscle spasms (121)
7. Reducing nausea and potentially other digestive issues, which can help with recovery
8. Reducing performance anxiety

Here are a handful of specific studies:

• A 2023 study found that topical CBD cream reduced pain in 20 retired professional athletes (1)
• A 2020 study found that CBD reduced DOMS following barbell squats in 23 people (1)

This helps explain why an increasing number of athletes have come out in support of using CBD, including MMA fighters Nick Diaz and Bas Rutten, football player Rob Gronkowski, and basketball player Lamar Odom.

CBD and Obesity

CBD is not a magical weight loss pill and you should be weary of anyone making outrageous claims about it. Having said that, there is some interesting early research suggesting that CBD may reduce appetite and have other weight loss benefits.

Most notably, a 2022 review of 11 clinical studies concluded that CBD can reduce appetite and lead to weight loss (1). However, it’s important to keep in mind that most of the studies they looked at used large doses of pure CBD, which is unrealistic in the context of real-world CBD use.

It’s more realistic that CBD can help people lose weight indirectly, through its positive effects on things like sleep, anxiety, mood, and stress.

CBD & Brown Fat

Additionally, a 2016 petri dish study out of South Korea reported interesting findings. The researchers applied CBD to mouse adipocytes (fat cells). They found that CBD “browned” the cells, which means they took on the characteristics of brown fat cells, including increased lipolysis (breakdown of fat) and reduced lipogenesis (fat production) (122).

To give a quick overview, there are three types of fat tissue: 

• White fat, the fat most of us are familiar with
• Brown fat, a special type of fat tissue that burns fatty acids to produce heat 
• Beige fat, which is somewhere between the two

Brown fat is especially common in babies but is also present in some parts of the body in adults. Brown fat is currently being explored as a novel way to combat obesity. 

The researchers of the study concluded that “CBD may be explored as a potentially promising therapeutic agent for the prevention of obesity.” 

Multiple Sclerosis

Early research indicates that CBD may have beneficial effects on multiple sclerosis (MS). 

Multiple studies in mice with autoimmune encephalomyelitis (EAE), a condition used as an animal model of MS, found that CBD improved the disease by reducing inflammation and either suppressing or boosting the activities of certain immune cells (125, 126).

The researchers of one of these studies concluded that CBD “may constitute an excellent candidate for the treatment of MS and other autoimmune diseases” (127).

Another study found that CBD reduced inflammation in a viral model of MS (128).

Aside from that, several human studies have shown that Sativex — a drug that combines equal amounts of CBD and THC — can help with multiple symptoms of MS. One 2005 paper reviewed the results of five clinical trials of Sativex and found that it significantly improved neuropathic pain, spasticity, muscle spasms, and sleep disturbances in MS patients (129).

In summary, as concluded by a 2023 review paper, “…even based on the limited evidence so far available, CBD appears as a highly promising drug with significant immunomodulating and disease-modifying potential for MS.” (1)

Asthma

Given CBD’s potent anti-inflammatory and immunomodulatory effects, it’s not surprising that it might also be beneficial for asthma.

One Brazilian study in rats with asthma found that CBD reduced the levels of pro-inflammatory molecules called cytokines, which play a key role in the condition (130). Similarly, a study in mice with asthma found that CBD decreased airway inflammation and other signs of asthma (131).

Although human research is needed, these early findings suggest that CBD can be beneficial for asthma sufferers.

Bone Health

Recent research has shown that bone cells and the skeleton as a whole contain endocannabinoids, their enzymes, and cannabinoid receptors, suggesting that the ECS plays a role in bone health (132). 

As such, CBD many have some bone benefits. For example, one 2015 study found that CBD promoted the healing of fractures in rats and improved bone strength (133). A similar 2023 study found that CBD and the minor cannabinoid CBG relieved pain and promoted bone healing in mice with bone fractures (1).

Meanwhile, a study done on isolated cells found that CBD promoted osteoblast differentiation, the process through which stem cells from your bone marrow turn into osteoblasts: the cells that build new bone (134). 

Similarly, other studies have found that CBD can help with bone healing and regeneration through its effects on these stem cells (135, 136).

Although human studies are needed, these early findings suggest that CBD could help with osteoporosis, fractures, and other bone conditions characterized by loss of bone mass.

How Does CBD Work?

CBD works in two main ways:

1. interacting with your body’s endocannabinoid system (ECS).
2. Interacting with other parts of the body, including various receptors, enzymes, and proteins.

So far, researchers have identified over 76 different CBD “mechanisms” — ways that it interacts with and impacts the body. (5). This helps explain why CBD seems to have so many wide-ranging effects and potential benefits. 

First, let’s get a basic understanding of the endocannabinoid system since it plays a key role in CBD’s effects and your overall health.

The Endocannabinoid System

Discovered in the early 1990s, the endocannabinoid system (ECS) is a crucial biological system consisting of three parts: (6)

1. Endocannabinoids: cannabinoids made in your body. The two main ones are called anandamide and 2-arachidonoylglycerol (2-AG).
2. Enzymes: molecules that build and break down endocannabinoids. The two most important ones are FAAH (breaks down anandamide) and MAGL (breaks down 2-AG) (7).
3. Cannabinoid receptors. Receptors are proteins found in cells that respond to specific compounds and produce a resulting effect. Cannabinoid receptors respond to both phytocannabinoids (plant-derived) and endocannabinoids (made in the body). You can think of them as locks that are only opened by the right key. The two main cannabinoid receptors are CB1 and CB2, but researchers believe there could be more (8). CB1 is abundant in the brain, while CB2 is common in immune system tissues (9). 

The main role of the ECS is to maintain homeostasis — a term for a healthy state of balance. To do that, the ECS regulates virtually all of your body’s essential processes, including: (10)

• Memory, learning, and neuronal development
• Mood, stress, sleep, and emotions
• Metabolism, appetite, and digestion
• Cardiovascular, liver, and skin function
• Immunity and inflammation
• Pain
• Body temperature
• Reproduction

One simple way to understand the role of the ECS is to think of anxiety. We need to feel some anxiety to get things done. For example, being anxious about a job interview can motivate you to prepare for it.

But if we get too anxious, it can wreck our mental health. Clearly, we need some anxiety, but not too much. This same concept can apply to virtually every other process in our body.

The ECS helps keep these processes running just right — not too much, and not too little. Whenever something upsets this delicate balance, like pain, inflammation, or anxiety, the ECS steps in to bring things back to homeostasis.

How CBD Affects the ECS

With that out of the way, how exactly does CBD interact with the endocannabinoid system? Unlike THC and your endocannabinoids, which directly bind to CB1 and CB2 receptors, CBD works a bit differently:

1. CBD works as an allosteric modulator: a compound that increases or decrease how cannabinoid receptors to other cannabinoids. So far, there’s strong evidence that is a negative allosteric modulator of the CB1 receptor, and early evidence that it might also affect CB2 (11, 12).
2. CBD increases the levels of the endocannabinoid anandamide, so you experience more of its beneficial effects, such as relief of pain, neuroinflammation, anxiety, and depression (1). Researchers believe that this is either because CBD inhibits FAAH, the enzyme that breaks down anandamide, or because it binds to proteins that transport endocannabinoids (14).

Anandamide is known as the “bliss molecule” because it seems to reduce anxiety, relieve pain, and have other beneficial effects (15). It might also be one of the compounds responsible for the euphoric feeling you get after strenuous exercise known as the “runner’s high” (16).

How CBD Affects Other Parts of the Body

CBD doesn’t just affect your endocannabinoid system. It also interacts with many other molecules in your body, including various neurotransmitter (brain messenger chemical) systems, a myriad of receptors, enzymes, and transporter proteins.

As we previously highlighted, researchers have found 76 separate “molecular targets” of CBD so far (5). Here’s a closer look at the key ones:

• CBD interacts with several G-protein-coupled orphan receptors (GPRs), which are considered “orphans” because scientists have yet to find which of our body’s molecules are supposed to bind to them (1). That includes GPR55, the leading candidate for what may one day be called the third cannabinoid receptor (CB3).
• CBD interacts with Nav channels, which are proteins that are especially common in nerve cells and play a role in the flow of calcium ions. This mechanism appears to be related to CBD’s anti-seizure effects (1). It also interacts with other ion channels, although the precise effects are more complex.
• CBD interacts with the 5-HT1A serotonin receptor, which regulates stress, anxiety, vomiting, and other cognitive functions (1). This mechanism is involved in CBD’s anti-anxiety and anti-nausea effects. CBD also seems to interact with 5-HT2A and 5-HT3, two other kinds of serotonin receptors.
• CBD may interact with the a7 nicotinic receptor, another receptor involved in brain function (1).
• CBD interacts with the GABA_A receptor, which is typically activated by GABA, the brain’s main calming neurotransmitter. This may produce anxiety-relieving and anticonvulsant effects (1).
• CBD interacts with glycine receptors, which are involved in motor control and pain perception (1). This mechanism may result in reduction of neuropathic and inflammatorypain.
• CBD interacts with numerous TRP channels, which are involved in immune function, sensing temperature, pain, releasing neurotrasmitters and more (1).
• CBD is an allosteric modulator of opioid receptors, which might explain its beneficial effects on opioid addiction (20).
• CBD blocks protein equilibrative nucleoside transporter 1 (ENT-1), increasing brain levels of the calming neurotransmitter adenosine. This may contribute to CBD’s neuroprotective, anti-inflammatory, and other beneficial effects (21, 22). CBD may also directly activate the adenosine A1 receptor.
• CBD may inhibit nuclear factor (NF)-κB, a family of proteins whose dysfunction is linked to inflammation, cancer, and autoimmune disorders (23).
• CBD activates the peroxisome proliferator-activated receptor gamma (PPARγ) receptor. This interaction is at least partially responsible for CBD’s effects on memory, Alzheimer’s, Parkinson’s, multiple sclerosis, anxiety, depression, cardiovascular and immune health, and cancer (24).
• CBD interacts with the sigma 1 receptor, which may be linked to CBD’s positive effects on seizures, stroke, neurodegenerative disorders, and other conditions (25).
• CBD inhibits the activity of cytochrome P450 superfamily (CYPs) of enzymes. These enzymes are involved in metabolizing about 70-80% of all clinical drugs, which is why high CBD doses can result in drug interactions (26, 27).
• CBD also inhibits some other enzymes, including AANAT, the enzyme that converts serotonin to melatonin, AChE and BChE, two enzymes that break down the neurotransmitter acetylcholine, and IDO, an enzyme that breaks down the essential amino acid tryptophan (1, 5).

Full-Spectrum vs. Broad-Spectrum vs. Isolate CBD

When shopping for CBD, you’ll encounter three kinds of CBD extract:

1. Full-spectrum: Whole-plant hemp extract containing CBD plus many other cannabinoids, terpenes, flavonoids, and other natural compounds. This is considered the most effective form of CBD.
2. Broad-spectrum: Same as full-spectrum but with THC removed (trace amounts may remain).
3. CBD Isolate: Purified CBD without any other compounds; the least effective form of CBD.

It’s important to understand the differences between these types of CBD so you can choose the best one for your needs.

Full-Spectrum CBD

Simply put, full-spectrum CBD is a whole-plant hemp extract. As such, it contains all of the cannabinoids (including up to 0.3% THC) and terpenes naturally found in hemp, as well as flavonoids, fatty acids, minerals, and other phytochemicals (plant compounds).

Research suggests that all of these compounds (cannabinoids and terpenes in particular) work synergistically with each other, creating what scientists call the cannabis entourage effect (27). Thanks to this effect, full-spectrum CBD is believed to be much more effective than pure CBD on its own.

For example, research in epilepsy patients has shown that full-spectrum CBD may be up to four times more potent than pure CBD and cause fewer side effects (28).

Minor Cannabinoids

After CBD, the most important component of full-spectrum extracts are minor cannabinoids, which get their name for their relatively small concentrations (typically below 1% of the plant’s dry weight). Cannabis (marijuana and hemp) plants can contain as many as 120 minor cannabinoids, with the most prominent ones being:

1. THC (since its levels in hemp are below 0.3%)
2. CBG
3. CBN
4. THCV
5. CBC
6. CBDV

Broad-Spectrum CBD

Broad-spectrum CBD is the same as full-spectrum except the THC has been removed to a point where it’s not detectable by lab tests (which means it’s as close to 0% as possible).

This type of whole-plant extract also benefits from the entourage effect. However, it’s slightly weaker since you’re not getting THC, which contributes some beneficial synergistic effects.

People typically choose broad-spectrum CBD products when they need to avoid THC due to:

• High THC sensitivity. Some people (like me, the person writing this guide) are extremely sensitive to the effects of THC, which means full-spectrum CBD can give them anxiety.
• Employee drug testing. In the US, it’s common to be tested for marijuana by your employer (although it’s becoming less frequent as using cannabis becomes more socially accepted). These tests look for the metabolites of THC, so if you take a full-spectrum CBD product, you can test positive.

CBD Isolate

As the name suggests, CBD isolate is pure CBD and nothing else. It comes in the form of an odorless, tasteless white powder and is made by isolating CBD from all other cannabinoids and hemp compounds. Isolate can be sold in its powder form or blended with other ingredients to make CBD oils, gummies, and other types of products.

CBD isolate does not benefit from the entourage effect since you’re not getting any other hemp phytochemicals. As such, it’s significantly less effective than full and broad-spectrum CBD.

People usually buy pure CBD isolate when they want to:

• Make their own DIY CBD oils and other products, or add the isolate to coffee, tea, and other beverages or foods
• Save money, because CBD isolate powder is arguably the most cost-effective way to use CBD
• Avoid THC (although broad-spectrum CBD is the better option)

CBD isolate usually contains over 99% CBD. However, it might also have tiny amounts of the minor cannabinoid CBDV because it has a similar molecular structure, so some CBDV can remain after refining (29).

Isolate also happens to be the most common form of CBD used in research studies because researchers prefer to study compounds in isolation.

A Word on Nano CBD

You might occasionally run into CBD products that mention “nano CBD” or “water-soluble CBD.” Such products are made using nanotechnology, which deals with things of a very small (nanometer) size.

Using nanotech for CBD is a great idea because it solves a key problem: low oral bioavailability. In simple terms, this means that CBD is poorly absorbed when you swallow it (as a capsule, gummy, or another oral product) because it’s a fat-soluble compound that doesn’t dissolve in water.

The most common approach is called nano-emulsification or nanoemulsion, where the CBD molecules are broken down into a tiny size to allow them to disperse (but not mix) in water, greatly improving their absorption. Some companies use this technology to formulate their CBD oils and drinks.

Research suggests that nanotechnology can improve CBD’s absorption by severalfold (30). Having said that, more research is needed. Besides, it’s difficult for you to confirm that the nanotechnology used in a specific CBD product matches the methods used in studies. 

Bottom line: For now, nano CBD is mostly a marketing tactic. Until there’s more solid evidence, don’t buy into any outrageous claims about nano CBD.

CBD Consumption Methods

There are multiple ways to take CBD. The four most common methods are:

• Sublingual: put CBD under your tongue
• Oral: ingest CBD
• Inhalation: smoke or vape CBD
• Topical: apply CBD to your skin

You could also inject CBD into your veins, use it as a suppository (rectum or vagina), and spray it into your nose. However, these methods are rarely used for obvious reasons so we’ll stick to the main ones. 

There isn’t one best method of introducing CBD into your body because they all have their advantages and disadvantages. Here’s a closer look at the differences between the four main options.

Method	Absorption	Time to Effects	Average Duration	Product Types
Sublingual	Medium-High	10-30 min	4-8 hours	CBD oil, spray, isolate
Oral	Low	30-120 min	6+ hours	CBD capsules, edibles, drinks
Inhalation	Medium-High	Seconds	1-4 hours	CBD vape e-liquid, CBD hemp flower
Topical	Medium	10-60 min	2+ hours	CBD cream, lotion, patches

Sublingual CBD

The sublingual route is the most common and popular way of taking CBD. This is when you put the active ingredient (in this case, CBD) under your tongue to allow it to absorb directly into the blood vessels. After the CBD oil is held for at least 60 seconds, you can swallow it.

The sublingual method is preferred over taking CBD orally because it avoids the digestive tract. It’s also cost-effective, allows you to easily raise or lower the dosage easily, and has long-lasting effects.

The sublingual CBD route takes about 15-40 minutes to be felt (137) and its effects last for about 4-6 hours.

Oral CBD

The oral method is when you swallow CBD, usually as capsules, softgels, gummies, or another edible product. The reason why this method is not as popular as CBD oil is because CBD and other cannabinoids have notoriously low oral absorption (138).

In simple terms, when you ingest CBD it has to first go through the digestive tract and the liver before it can be absorbed into the blood: a concept known as first-pass metabolism (139). Due to this, most of the CBD is lost before it reaches systemic circulation.

That’s why oral CBD has low bioavailability — the portion of a substance you take that’s actually absorbed by the body. If you were to inject CBD (or any other substance) into the veins, it would have 100% bioavailability since it’s going directly into the bloodstream.

Various research studies have reported that the oral bioavailability of CBD ranges anywhere from 6 to 19%, which means that over 80% of the CBD is lost (140, 141). Oral CBD can also take a long time to start working, depending on how much and when you ate. 

On an empty stomach, it can work within 30 minutes, but if you’ve eaten it can take upwards of two hours.

So if they’re poorly absorbed, why use oral CBD products at all? The answer is convenience.

It’s incredibly easy to take a capsule, softgel, or a tasty gummy. Besides, you don’t need to measure doses and get a precise amount of CBD every time.

You can also take these products anytime and anywhere, and their effects tend to last the longest out of any CBD product: over six hours (142). Capsules and gummies are also easy to incorporate into your existing supplement routine.

Inhaled CBD

Inhaling CBD through vaping or smoking dried CBD hemp flower is another popular method. The main advantage of inhaling CBD is that the effects are nearly instantaneous. 

This means vaping/smoking is the best choice for people who require instant relief, such as someone who suffers from panic attacks. Research suggests that inhaling CBD has similar bioavailability to the sublignual method — as high as 60% (143). 

Inhaling CBD can also be more enjoyable than other methods. For example, if you vape, you also get to taste pleasant flavors and produce vapor clouds.

The major downside of the inhalation route is that its effects last less: about 1-4 hours on average (142). 

Also, although vaping is considered much safer than smoking, there’s growing evidence that it carries some health risks, particularly in terms of lung and cardiovascular health (more on that in the safety section).

Topical CBD

The final option is to apply CBD to your skin in the form of a cream, lotion, balm oil, or another topical product. This method differs from the others because its effects are localized. 

That means you will only get the benefits exactly where you applied the CBD, rather than your whole body. That’s because topically applied CBD doesn’t absorb well enough into the skin to reach the blood and only has effects on that particular area. 

This makes topicals ideal for localized concerns such as skin conditions or muscle/joint pain and soreness (138). Topically applied CBD takes about 10-60 minutes to start working and its effects usually last for a few hours. 

Researchers are also developing transdermal formulations which allow CBD and other cannabinoids to pass through the skin and reach the blood vessels, providing the systemic (body-wide) effects you’d get from other methods (144). 

Theoretically, these products can continuously deliver CBD into the blood for up to 48 hours with fewer side effects than other routes.

However, this technology is still in its early stages and there’s no way to verify the effectiveness of any topical product that’s claimed to be transdermal.

How to Improve CBD Absorption

CBD is not easy for our bodies to absorb. Here are some evidence-based tips to maximizing CBD absorption and bioavailability.

• If you’re taking CBD sublingually, hold it for at least a minute but ideally 3 minutes or even longer. The longer you hold it, the more CBD will absorb into the blood vessels. 
• If you’re taking CBD orally, take it with a high-fat meal. Several studies have shown that fats improve the oral bioavailability of cannabinoids. In one 2016 study, CBD given to rats with fat had 3 times higher absorption (145). Meanwhile, in a 2019 study epilepsy patients took pure CBD capsules while fasting or after eating a high-fat meal (breakfast burrito with 500-600 calories of fat). Taking CBD while fasting has an absorption rate of only 6%, but that increased fourfold to 24% when taken with a high-fat meal. (146). This tip is less important if you’re taking CBD as softgels, brownies, or other oral products that already contain some fats, but you’re still likely to see greater absorption. We even recommend this tip for CBD oil because some of it will be absorbed orally after you hold it under your tongue and swallow.
• If you’re inhaling CBD by vaping or smoking, make sure you’re actually breathing it into your lungs and not immediately exhaling. Although there’s little research in this area, a good rule of thumb is to follow one of the two main smoking/vaping methods: direct-to-lung (directly inhaling into your lungs) or mouth-to-lung (inhale into mouth first and again into the lungs).
• If you’re applying CBD topically, make sure your skin is dry and massage the product in to maximize absorption. 

For more detailed information, check out our guide to improving CBD absorption.

What’s the Best Time to Take CBD?

The best time to take CBD depends on your goals. Some people take CBD as needed, such as when they’re experiencing pain or anxiety.

Others, especially individuals dealing with chronic issues, take CBD every day at set times, such as the morning, before bedtime, or with meals. 

In this case, the exact timing might depend on the issue. For example, if you have sleeping problems, you’d always take CBD about 20-60 minutes before bed. Meanwhile, if you suffer from work-related anxiety, you might take CBD after waking up and again at lunchtime. 

Types of CBD Products

CBD comes in many different types of products. CBD oil is the best all-around option for most people, but there are a lot of factors to consider, such as convenience, portability, bioavailability (absorption), and duration of effects. 

Here’s a closer look at the available options. 

CBD Oil

CBD oil is the most popular type of CBD product. You’ll also see it be called a CBD tincture, although this term isn’t technically correct because tinctures are supposed to contain alcohol.

CBD oil is made by taking a CBD-rich hemp extract and dissolving it in what’s called a carrier oil — an oil-based ingredient that helps the body absorb CBD and makes it easier to dose. 

The most common carrier oil is coconut-derived MCT oil, but others, such as hemp seed, grape seed, and olive oil are also used. 

CBD oils can either contain pure CBD isolate or a CBD-rich, whole-plant extract (full or broad-spectrum). Some companies also add other active ingredients like turmeric for anti-inflammatory benefits or melatonin for sleep.

The standard way to use CBD oil is sublingual (holding it under the tongue). However, you can also apply CBD oil to your skin or add a few drops to foods and beverages. 

CBD Capsules

CBD capsules and softgels are another popular CBD product type. Just like CBD oil, they can contain CBD isolate or whole-plant extract. Capsules are convenient but as we discussed earlier, suffer from low absorption (which can be greatly improved by using them alongside a fat-heavy meal). 

Capsules typically contain dry ingredients, whereas softgels contain CBD extract dissolved in a carrier oil, giving them greater absorption. Learn more about the differences between CBD capsules and softgels.

CBD Gummies and Other Edibles

CBD gummies are the tastiest way to get the benefits of CBD. You can also find CBD-infused chocolate, cookies, candy, and other edible products. Again, like capsules, their major downside is poor oral absorption. 

Also, virtually all gummies and most other CBD edibles are made with isolate because it’s difficult to formulate full-spectrum hemp extracts into an edible product. That’s yet another reason why CBD edibles are less potent than most other product options.

CBD Vape Products

CBD vape e-liquids, pre-filled cartridges, and disposable vape pens give you the option to vape CBD. 

Most CBD vape products contain isolate dissolved in a standard vape ingredient base of vegetable glycerin (VG) and propylene glycol (PG). Some also use MCT oil or a new type of vape carrier called Tec Temper as the carrier base. 

You can also find products that add in specific blends of cannabis terpenes or even use whole-plant hemp extracts instead of pure CBD.

If you want to vape properly, you should buy your own vape device since disposable CBD vape pens will be more expensive over time and tend to have low potency.

However, there are some safety concerns with vaping (more on that later).

CBD Topicals

Topical CBD products are applied to the skin and come in a wide variety of options, including creams, balms, salves, lotions, massage oils, cleansers, and serums. You’ll find as much variety here as regular cosmetic and skincare products.

CBD Transdermal Patches

Considered a subset of topical products, transdermal patches are also applied to your skin. However, the difference is that they’re supposed to penetrate through the skin into the blood, which should result in systemic rather than localized effects. 

CBD Isolates & Concentrates

This category includes 99% pure CBD isolate powder, terpene-infused isolates, CBD paste, and CBD versions of cannabis concentrates like shatter, wax, and rosin.

You can use these products by putting them under the tongue, adding them to foods or drinks, vaping/smoking them, or making DIY CBD oils, vape juice, and other preparations. 

Concentrates like CBD shatter and wax can also be dabbed.

CBD Drinks

CBD-infused beverages are one of the latest additions to the CBD market. You can find CBD coffee, tea, water, sodas, juice, sports drinks, and even alcoholic beverages.

Since these products are absorbed orally, in the same manner as capsules and gummies, their effects will not be as potent as CBD oil. Many CBD beverages are made with nanotechnology because CBD and water naturally don’t mix. 

This allows the CBD to at least disperse in the water but at this point, it’s hard to say whether this offers any advantages in terms of absorption.

CBD Bath Bombs

CBD-infused bath bombs are not the most efficient way to use CBD because it doesn’t dissolve in water so you’ll need high doses (50-100 mg) to feel an effect. However, they can provide a unique method of relaxation.

CBD Gum

CBD gum is unique because it’s technically edible but may be absorbed as effectively as CBD oil because it can dissolve into the blood vessels in the cheeks, gums, and under the tongue.

How Are CBD Products Made?

All CBD products start out as hemp. After being harvested, the aerial (above-ground) parts of the plant are extracted with a solvent such as CO2 or ethanol to produce a whole-plant, CBD-rich extract (147).

Hemp flowers are usually the main part of the plant used to make CBD products because they’re rich in hair-like trichomes, which hold most of the cannabinoids and terpenes. However, the stalks, stems, and leaves of hemp can be utilized as well.

The resulting whole-plant, CBD-rich hemp extract contains not only cannabinoids but many beneficial and inactive compounds, including terpenes, flavonoids, vitamins, minerals, and fatty acids.

This extract can then be further refined to produce full-spectrum, broad-spectrum, or isolate CBD. 

Finally, the CBD extract is blended with other ingredients depending on the specific type of product. For example, if you’re making a CBD oil, the extract is dissolved in a carrier oil such as MCT oil.

CBD Extraction Methods

There are two main ways to extract CBD and other beneficial compounds from hemp: alcohol (ethanol) and CO2 (carbon dioxide) extraction.

Both of these methods are perfectly safe and effective and are used by the vast majority of CBD companies. Another, less-common option is called lipid infusion, where hemp is soaked in oil and heated to infuse it.

CBD Dosage

The right amount of CBD to take varies from person to person and there’s no official health expert consensus or recommendation.

Dosage can be influenced by many variables, including:

• Body weight
• Genetics
• The type and severity of your symptoms
• The CBD concentration of your product
• The method you’re using to introduce CBD into your body
• The type of extract used in your product

That’s why a dose that works for someone could be completely insufficient for another person. Here’s a closer look at each of these variables.

Body Weight

Generally speaking, people who weigh more will need to take higher CBD doses to feel the same effect as smaller individuals. You can use the following table as a general starting point (these doses are measured in CBD isolate, which is weaker than whole-plant CBD extracts).

Estimated Pure CBD Doses by Weight and Strength

Weight (lbs)	Low Dose	Medium Dose	High Dose
100 lbs	10 mg	30 mg	60 mg
125 lbs	13 mg	38 mg	75 mg
150 lbs	15 mg	45 mg	90 mg
175 lbs	17 mg	52 mg	105 mg
200 lbs	20 mg	60 mg	120 mg
225 lbs	22 mg	67 mg	135 mg
250 lbs	25 mg	75 mg	150 mg

Body Chemistry and Genetics

Everyone’s body chemistry is different, which can influence how CBD affects us. The best example of this is genetic differences in your endocannabinoid system. 

For example, some people have a genetic variation that reduces the activity of the enzyme which breaks down the endocannabinoid anandamide. As a result, these individuals have naturally higher anandamide levels, which may contribute to lower overall anxiety (148). 

Since CBD also works by suppressing this enzyme, it’s possible that people with this genetic variation could be less responsive to CBD’s effects.

There are also many variations of the genes responsible for your cannabinoid receptors which can also affect how your body responds to cannabinoids.

On top of that, genes can also influence your metabolism, which can affect how specific drugs (such as CBD) will affect you (149).

The bottom line is that your unique body chemistry can make you less or more responsive to the effects of CBD.

Your Symptoms

The type and severity of the symptoms you’re attempting to deal with will also affect the dosage. Someone looking to reduce occasional anxiety will likely require lower CBD dosages than a person looking for relief from chronic pain caused by cancer or another debilitating condition.

CBD Extract Type

As we discussed earlier, full and broad-spectrum CBD extracts are more effective than pure CBD isolate. As a result, products made with these whole-plant extracts will likely require lower doses than those made with isolate. 

This is yet another factor to consider when choosing how much CBD you should take. 

CBD Delivery Method

How you’re taking CBD also matters. Most importantly, if you’re taking an oral CBD product, you can expect weaker effects than the sublingual or inhaled routes. 

That means you’ll need to up your dose when taking capsules, gummies, and other ingestible products to get the same effects of CBD oil or vape juice. 

CBD Concentration/Potency

You also need to be aware of the concentration of your CBD product when choosing your dosage. 

Also known as the potency or strength, this refers to the amount of CBD per ml of liquid or per capsule, gummy, beverage, or another type of product.

For example, the CBD oil above has a potency of 50 mg/ml, which means one full dropper will provide 50 mg of CBD. We also know that since the volume is 15 ml, that means the whole bottle contains 750 mg of CBD.

As another example, let’s say you have two 30 ml CBD oils. 

One contains 900 mg of CBD while the other has 300 mg. If we divide this total amount by the volume (30 ml), we arrive at a potency of 30 mg of CBD per ml for the first oil, and only 10 mg/ml for the second one. The second oil will obviously be much weaker.

As a general rule of thumb, CBD products can be divided into three potency levels:

• Low: 1-15 mg/ml
• Medium: 16-40 mg/ml
• High: 50+ mg/ml

The potency will usually be listed on the product. If it isn’t, simply divide the total amount of CBD by the volume. 

How Much CBD Should You Take?

As we can see, there are many factors that can affect your CBD dosage. That’s why researchers recommend following the “start low and go slow” method to dosing cannabinoids (150). 

Here’s what you do: start with a small CBD dose (10-15 mg) and see how it makes you feel. If you don’t notice any effects, you can take a bigger amount either a few hours later, or take the same dose for a few days before increasing it.

Use this method to incrementally increase your dosage, making sure to stop and wait to see if you feel any effects. Continue to do this until you find the CBD amount that provides you with the desired effects and stick to it. 

As a general rule of thumb, the average person takes about 20-120 mg of CBD per day in one or two doses. Some people also find that they need to take CBD for a few days or even weeks before they notice an effect.

Can You Overdose on CBD?

It’s legitimately difficult to take too much CBD. Research studies have shown that daily doses as high as 1500 mg were tolerated well by patients (151). 

CBD Safety

According to decades of research, CBD is a remarkably safe substance. It’s so safe, in fact, that the World Health Organization (WHO) concluded in its 2018 report that “CBD is generally well tolerated with a good safety profile” (152).

However, there are still some safety-related concerns to be aware of, such as possible side effects and interactions with prescription medications.

Side Effects

Human research studies have reported that CBD can cause minor-to-moderate side effects, including: (153)

• Fatigue/tiredness
• Sleepiness/drowsiness
• Diarrhea
• Dry mouth
• Low blood pressure
• Lightheadedness
• Changes in appetite/weight

Having said that, all of these side effects have only been reported in studies using very high oral doses of pure CBD (300 mg and higher).

This isn’t a realistic representation of how CBD is taken since most people use:

• CBD oil instead of capsules and other oral products
• Full and broad-spectrum products rather than CBD isolate

In short, your chances of experiencing side effects from CBD are low, and even if you do get them, they’re likely to be relatively small. 

Effects of CBD on Prescription Drugs 

As we noted earlier, CBD can also affect two types of molecules that help your body metabolize a wide variety of drugs: (26)

• The CYP450 family of liver enzymes
• The P-glycoprotein transport protein 

The CYP450 enzymes are involved in metabolizing over 60% of all prescription medications, which means high doses of CBD can increase (or in some cases decrease) the effects of many prescription drugs (154).

For example, a 2021 study found that CBD may increase the levels of the SSRI antidepressant citalopram (Celexa) (155).

The full list of affected drugs includes blood thinners, antidepressants, muscle relaxants, anti-epilepsy drugs, cancer drugs, antipsychotics, and many other drugs (156). 

Similarly, P-glycoprotein is involved in the metabolism of many drugs, including antivirals, immunosuppressants, and chemotherapy medications (157).

CBD’s effects on drug metabolism are unlikely to occur unless you’re taking really high doses. Still, it’s best to talk to your doctor before using CBD if you currently take any prescription medications.

Side Effects of Full-Spectrum CBD Products

There is one other thing to keep in mind in terms of side effects. As we discussed earlier, a minority of people are highly sensitive to the effects of THC. 

That means it’s theoretically possible to get high and feel anxiety, paranoia, and other unwanted mind-altering effects from taking a sufficiently high dose of a full-spectrum CBD product. 

If you’re one of these THC-sensitive individuals, consider taking a lower dose or switching to broad-spectrum CBD for anxiety.

Safety of Vaping CBD

Although CBD itself is quite safe, vaping does carry some health risks. Any kind of vaping, regardless of whether it includes nicotine, CBD, or just pure VG and PG, may have a detrimental effect on your health. 

There has been growing research in this area, with key studies suggesting that:

• Vape products can produce toxic chemicals (158)
• Vaping can increase your risk of heart attack and other cardiovascular and lung conditions (159, 160)
• Vaping can contribute to coughing, wheezing, and asthma (161)
• In very rare cases, vaping can cause vaping-related lung injury, which led to thousands of hospitalizations and dozens of deaths in 2019 and 2020 (162)

Is CBD Safe for Your Liver?

One recent study of mice caused quite the uproar by making it seem like CBD is toxic to your liver and can cause liver injury (163). This study has been a big talking point for the FDA’s negative stance towards CBD.

The problem with this study is that it administered ridiculously large doses of CBD to mice; doses that would be equivalent to adult humans taking grams of CBD at a time. 

As such, CBD is perfectly safe for your liver unless you take ridiculously large amounts.

Is CBD Addictive?

CBD is a completely non-addictive substance and you won’t suffer any withdrawal symptoms if you stop using it.

What’s more, as we discussed earlier, there’s growing evidence that CBD can actually help with addiction to many different substances, including opioids, cocaine, psychostimulants, cannabis, cigarettes, and even alcohol (164).

Can you Develop a Tolerance to CBD?

Human studies have not found any evidence that you can become tolerant to the effects of CBD over prolonged use (165).

However, this is still up to debate because the research is not 100% conclusive. Anecdotally, many people say they require larger doses to get the same effects when they’ve been using CBD for several months or years.

CBD and Drug Tests

Many people have to undergo employee drug testing. Can you test positive on these tests if you use CBD products? Yes, but it depends.

Drug tests look for the presence of THC in your body. Since full-spectrum CBD products contain small amounts of THC (0.3% or less), they can result in a positive drug test.

That’s why people who undergo drug testing should opt for broad-spectrum or isolate CBD products, which are completely free of THC.

To reiterate, CBD itself is not detected by drug tests. It’s only when you take full-spectrum products containing THC that there’s a chance of failing a test.

Endocannabinoid Deficiency

Clinical endocannabinoid deficiency (CEDC) is a theory that was proposed by esteemed cannabis researcher Dr. Ethan Russo in 2001.

This theory argues that insufficient endocannabinoid levels or other malfunctions of your endocannabinoid system are responsible for certain health conditions that have proven difficult to treat.

Research over the past two decades has found particularly strong evidence that CEDC may be responsible for migraines, fibromyalgia, irritable bowel syndrome (IBS) (166).

How does this relate to CBD? 

Since CBD can essentially “stimulate” your endocannabinoid system by increasing endocannabinoid (anandamide) levels, it may have a positive effect on this deficiency and by extent the conditions associated with it.

CBD Benefits for Pets

You may be surprised to learn that the endocannabinoid system is present in many other animals, including dogs and cats. In fact, this system is over 500 million years old and can even be found in birds, fish, and reptiles (167).

That means that CBD may have benefits for cats and dogs. Indeed, both suffer from many of the same issues we take CBD for, including anxiety, arthritis, pain, inflammation, skin, and digestive disorders. 

Although research in this area is limited, early findings are promising. For example, a 2018 study found that CBD improved comfort and activity in dogs with osteoarthritis (168).

Having said that, cats and dogs require smaller doses than us due to their smaller size and differences in their endocannabinoid system. 

Dogs, for instance, have more cannabinoid receptors in the brain than we do, which makes them especially susceptible to the intoxicating effects of THC (169). That’s why many CBD companies offer dedicated products for pets.

Choosing the Right CBD Brand

The CBD industry is not heavily regulated, which means there are plenty of low-quality products. You certainly don’t want to buy CBD from the gas station.

Choosing a reputable CBD brand will take some research. Here are the main factors and tips to consider. 

Look for Third-Party Tested Companies

The CBD industry is completely unregulated, so there isn’t much stopping companies from selling low-quality products. That said, third-party testing is the best way to protect yourself.

Performed by an independent lab, these tests check whether a product contains as much CBD and other cannabinoids as advertised. They can also look for the presence of pesticides, heavy metals, and other contaminants.

Third-party testing is the only way to make sure you’re getting a safe and effective CBD product. 

Any CBD company worth its salt is expected to utilize third-party testing and make the results of these tests (called Certificates of Analysis, CoAs) available on its website.

 If the test results are missing, this is a major red flag.

Check The Hemp Source

Since CBD is extracted from hemp, the way the plants are grown also plays a role in product quality.

The best CBD products are derived from organic hemp, which is usually grown in one of three states: Colorado, Kentucky, or Oregon.

European countries such as the Netherlands are also great places to source hemp, due to the continent’s rich history of hemp cultivation. 

It’s even better if you find a company that:

• Is vertically integrated, which means it does everything from growing the hemp to making the finished CBD products instead of sourcing them from someone else
• Has U.S. Hemp Authority certification, a third-party program that certifies that hemp producers follow strict quality standards
• Has USDA Organic certification, the best way of confirming that a product is actually grown organically. This certification is currently difficult to obtain for hemp, but some companies do have it. 

Again, all of this information should be easy to find on the company’s website.

Read Customer Reviews

Customer reviews are a great way to check if a CBD company can be trusted. You can read reviews directly on the company’s website, as well as independent sources like Trustpilot.com and Reddit.com, where the chances of fake or sponsored reviews are low.

It’s always a good idea to do some research and compare different review sources to make sure you’re getting multiple viewpoints and opinions. 

Look for Transparency

Trustworthy CBD companies have nothing to hide. They explain how their products are made, where they’re sourced from, and post easily accessible, up-to-date third-party tests.

Transparent brands also provide as much extra information as possible, like when the company was founded, by who, and product details. Finally, reputable companies have excellent customer service. They respond to your questions promptly and provide helpful answers.

Choosing the Right CBD Product

After you find a reputable CBD company, you still need to choose a product that fits your needs. Here are the key factors for you to keep in mind:

• Choose the consumption method: If you want the best overall effects, go with full-spectrum CBD oil. If you want convenience, go with capsules or gummies. If you want immediate effects, vaping is your best bet. Finally, for localized skin or muscle/joint concerns, topical products work best.
• Choose the type of CBD: If you want to get the most benefits out of CBD, opt for full-spectrum products. If you want to avoid THC, choose broad-spectrum products. If you want to make your own CBD preparations or save money by buying in bulk, choose CBD isolate. 
• Choose the potency: If you’re new to CBD, start out with a product that provides about 10-20 mg of CBD per dose. If you’re a more seasoned user and know which dosage works best for you, find a product that matches that. Generally speaking, the more severe your issue, the higher the CBD potency you’ll need to find relief.
• Consider how long you need the product to last: How often and how much will CBD you be using? This will determine how big of a bottle/how many capsules/gummies you need to buy. Let’s say you plan on taking 30 mg of CBD daily and want your CBD oil to last a month. That means you should look for one that contains at least 900 mg of CBD in total.

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