The Ultimate Guide to CBD: Everything You Need to Know

By | last updated March 29, 2023

Medically reviewed by
Saira Zulfiqar, PharmD

Evidence Based 171

You’ve probably heard of CBD oil. Celebrities and athletes are endorsing it and the media is constantly talking about it.

More importantly, millions of people all over the world are using 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?

In this comprehensive, evidence-based guide, we’re going to answer these and many other questions about CBD. We’re going to go in-depth and look at evidence from 150+ studies.

Here’s everything you need to know about CBD.

Table of Contents

What is CBD?

Cannabidiol (CBD) is a naturally occurring cannabis substance. It’s one of more than 120 compounds called cannabinoids (1). Most of the effects of cannabis — both recreational and medicinal — come from these natural compounds.

You’ve probably heard of tetrahydrocannabinol (THC) — the cannabinoid 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 beneficial effects on virtually every kind of health disorder. 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 get you high.

Where Does CBD Come From?

There are two types of cannabis: marijuana and hemp. Marijuana contains significant amounts of THC and lower levels of CBD. Hemp is the opposite: it has little THC (no more than 0.3%) but high CBD concentrations.

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


SourceUsually sourced from hemp (low THC, high CBD cannabis)Usually sourced from marijuana (high THC, low CBD cannabis)
IntoxicationNon-intoxicatingMakes you high
LegalityLegal in the United States and many other countriesIllegal in most countries and U.S. states
UsesDietary supplement, antiepileptic drugRecreational drug and medicine
Main Shared BenefitsPain, inflammation, nausea relief
Main Unique BenefitsAnxiety relief, anticonvulsantLowers eye pressure, stimulates appetite (3)
Common Side EffectsTiredness, drowsiness, diarrhea, dry mouthSimilar side effects to CBD, plus mind-altering effects such as memory impairment, anxiety, paranoia
Most Common ProductsCBD oil and CBD-only prescription drug EpidiolexMarijuana and THC-only prescription drugs

Hemp Oil vs. CBD Oil

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

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 plant. These parts of hemp are covered in hair-like 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 by definition. 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 after the country legalized all types of 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
  3. Medical-only use (by prescription)
  4. Completely banned

As a rough guideline, CBD is:

  • mostly legal in Europe
  • 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

How Does CBD Work? Meet the Endocannabinoid System

CBD works in two main ways: interacting with the endocannabinoid system and with other parts of the body. 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: (5)

  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) (6).
  3. Cannabinoid receptors. Receptors are proteins found in cells that respond to specific compounds and produce certain effects. 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 (7). CB1 is abundant in the brain, while CB2 is common in immune system tissues (8). 

The main role of the ECS is to maintain homeostasis — a scientific term for a healthy state of balance. To achieve that, the ECS regulates your body’s essential processes, including: (9)

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

A 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 your homeostasis, like pain, inflammation, or anxiety, the ECS steps in to bring things back into balance. 

How CBD Affects the Endocannabinoid System

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

CBD changes the function of the CB1 receptor, which might explain why it seems to reduce the intoxicating effects of THC when they’re taken together (10).

More importantly, CBD inhibits FAAH, the enzyme that breaks down the endocannabinoid anandamide (11). As a result, anandamide levels rise, so you get more of its beneficial effects.

Anandamide is known as the “bliss molecule” because it seems to reduce anxiety, relieve pain, and have other beneficial effects (12). It might also be one of the compounds responsible for the euphoric feeling you get after strenuous exercise known as the “runner’s high” (13). 

CBD can also bind to the proteins that transport endocannabinoids, such as fatty acid-binding proteins 1, 3, 5, and 7, which is another way that it may increase the effects of anandamide (14).

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, non-ECS receptors, enzymes, and transporter proteins.

So far, researchers have identified over 76 separate mechanisms or “molecular targets” that CBD works through (14). That’s a lot of possible effects!

Here’s a closer look at the key ones:

  • CBD may interact with the G-protein-coupled orphan receptors (GPRs), a group of receptors that are considered “orphans” because scientists have yet to identify which molecules are supposed to bind to them (15, 16).
  • CBD blocks GPR55, a GPR orphan receptor that is the leading candidate for the third cannabinoid receptor (CB3) (17).
  • CBD interacts with the 5HT1A (serotonin) receptor, which regulates stress, anxiety, vomiting, and other cognitive functions (14).
  • CBD may interact with serotonin 5HT3a and a7 nicotinic receptors, two other receptors involved in brain function (14).
  • CBD interacts with the GABAA receptor, which is typically activated by GABA, the main calming neurotransmitter. This may produce calming, anxiety-relieving effects (14).
  • CBD is a positive allosteric modulator of glycine receptors, which are mostly involved in motor control and pain perception (14).
  • CBD interacts with TRP receptors, such as TRPV1 and TRPM8, two receptors that detect hot and cold changes in temperature (18). These receptors are also activated by menthol and capsaicin, two common topical pain relievers (19).
  • CBD modifies the functions of delta and mu opioid receptors, which might explain its beneficial effects on opioid addiction (20).
  • CBD seems to increase the brain’s levels of adenosine, a calming neurotransmitter, which may be involved in its sleep-promoting effects (21).
  • CBD may inhibit nuclear factor (NF)-κB, a family of proteins whose dysfunction is linked to inflammation, cancer, and autoimmune disorders (22).
  • CBD can suppress the protein equilibrative nucleoside transporter 1 (ENT-1), which may play a role in its anti-inflammatory effects (23).
  • CBD seems to affect the (PPARγ) receptor, which may stimulate adult hippocampal neurogenesis (the growth of new brain cells in the adult brain), reduce inflammation, and produce other effects (24).
  • CBD may interact 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 many drugs, which is why high CBD doses can interact with medications (26).
  • CBD inhibits many other enzymes, including AANAT, the enzyme that converts serotonin to melatonin and IDO, an enzyme that breaks down the essential amino acid tryptophan (14).

Types of CBD

You’ll encounter three kinds of CBD extract: full-spectrum, broad-spectrum, and isolate. It’s important to understand the differences between them so you can choose the best type for your specific needs.

Full-Spectrum CBD

Full-spectrum CBD contains all of the cannabinoids and terpenes naturally found in hemp, as well as flavonoids, fatty acids, minerals, and other phytochemicals (plant chemicals). That includes over 120 minor cannabinoids.

Simply put, full-spectrum CBD is a whole-plant hemp extract. 

It’s believed to be the most effective form of CBD because all of its components provide beneficial effects of their own and also work together in synergy — what scientists call the cannabis entourage effect (27).

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

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.

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 effects.

People typically choose broad-spectrum CBD products when they want to maximize the benefits of CBD but avoid THC. There are two main reasons to avoid THC:

  • High THC sensitivity. Some people (like the author of this guide) are extremely sensitive to the effects of THC, which means full-spectrum CBD can cause anxiety
  • Employee drug testing. If you have to pass marijuana drug tests for your job, there’s a good chance that you will test positive when using full-spectrum CBD products since they can contain up to 0.3% THC

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. 

CBD isolate typically contains over 99% CBD but can sometimes carry traces of the minor cannabinoid CBDV because it has a similar molecular structure so it can stay behind during the refining process (29).

CBD isolate can be sold either as a pure powder 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 less effective than full and broad-spectrum CBD.

People usually buy 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

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

What is Nano CBD?

You might occasionally run into 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.

Nanotech is used in some products because CBD is a fat-soluble compound that doesn’t dissolve in water. This presents two problems. 

First, it’s difficult for our water-based bodies to absorb, especially when you swallow CBD instead of using other delivery methods. Second, it’s hard to formulate CBD-infused beverages since they don’t dissolve or mix well with water.

The most common method is called nano-emulsification or nanoemulsion, which breaks down CBD molecules into a tiny size to allow them to disperse (but not mix) in water, improving their absorption (30).

That’s why nanotechnology is mostly used in CBD drinks. However, it’s also increasingly used in other products, including CBD oil. 

Now for the big question — does nanotechnology actually improve CBD’s absorption as companies claim? 

Research suggests that it might.

Two studies compared the absorption of Sativex, a drug containing THC and CBD, with a nanoemulsion with the same cannabinoids. In both studies, the nano CBD/THC product resulted in greater bioavailability/absorption (31, 32).

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 Benefits

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

  • Antioxidant (33)
  • Anti-inflammatory (34)
  • Antiemetic (anti-nausea) (35)
  • Antidepressant (36)
  • Anxiolytic (anxiety relief) (37)
  • Antipsychotic (38)
  • Analgesic and antinociceptive (pain relief) (39)
  • Neuroprotective (40)
  • Anticonvulsant (41)
  • Antispasmodic (relieves muscle spasms) (42)
  • Anti-proliferative and chemopreventive (anti-cancer) (43)
  • Anti-angiogenic (reduces the formation of new blood vessels) (44)
  • Cardioprotective (45)
  • Antibacterial (46)
  • Antiviral, but only against certain viruses (47)
  • Immunomodulatory (helps normalize immune function) (48)
  • Anti-addiction properties (49)

With so many different effects, it’s no surprise that CBD may have a positive effect on 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 in cases that are resistant to standard treatment.

One review of 36 studies concluded that CBD reduced the number of seizures and stopped them entirely in some people (50).

As a result, the CBD-based drug  Epidiolex was approved in the U.S. and several other countries to treat Lennox-Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex (TSC), three rare and severe types of epilepsy (51).

Anxiety Disorders

Relieving anxiety is one of the most common uses of CBD. Several human studies have shown that CBD can relieve anxiety:

  • A Brazilian study found that CBD capsules reduced anxiety caused by public speaking in people with social anxiety disorder (SAD) (52)
  • A Japanese study found that CBD oil reduced anxiety in teenagers with SAD (53)
  • A Colorado study found that CBD reduced the symptoms of post-traumatic stress disorder (PTSD) in adults (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, PTSD, and obsessive-compulsive disorder OCD (55, 56).


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

There’s also a case report of a teenager with substance use disorder who suffered from severe depression, anxiety, and other mental issues. He not only improved his depression and other symptoms but was also able to quit the drugs by taking CBD (58).

However, these findings need to be replicated in high-quality clinical studies before we have solid evidence that CBD can help with depression in humans.

Pain and Inflammation

Pain and inflammation play a major role in many health disorders, including cancer, fibromyalgia, multiple sclerosis, and arthritis. Cannabis has been utilized to help with these and other pain-related issues for millennia (59).

Although these effects have been usually attributed to THC, recent research has demonstrated that CBD may also help with pain and inflammation.

For example, several animal studies have shown that CBD may help with arthritis:

  • Topical CBD treatment reduced pain and inflammation in the affected joints in rats with arthritis (60)
  • In another study, CBD given orally or by injection to mice blocked the progression of rheumatoid arthritis (61)
  • CBD reduced swelling and pain in rats with rheumatoid arthritis (62)

Meanwhile, a 2020 human study found that full-spectrum CBD oil helped people with chronic pain reduce prescription opioid painkiller use. 

After using the CBD oil for 8 weeks, over 50% of the 97 study participants lowered or stopped using painkillers and 94% said that CBD improved their quality of life (63).

Another study found that topical CBD oil improved neuropathic pain in 29 people (64).

Additionally, multiple studies of Sativex, a prescription drug combining equal doses of THC and CBD, have reported reductions in chronic pain. 

In one study, Sativex significantly reduced chronic pain caused by rheumatoid arthritis (65). A similar study in people with multiple sclerosis also reported reductions in chronic pain (66).

Finally, a 2020 review paper summarized that “CBD is a well-tolerated and safe natural compound exerting analgesic [pain-relieving] effects in various animal models of pain, as well as clinical studies” (67).

Sleep Disorders

CBD also has the potential to improve sleep. For example, early research found that CBD may have sedating effects at high doses (>160 mg) (68).

Another study found that CBD improved sleep during the first month of treatment in people with anxiety and sleep issues. However, these effects were only reported in 67% of the patients and seemed to fluctuate for the remaining two months of treatment (69).

Meanwhile, a study of CBD in people suffering from REM sleep behavior disorder reported positive effects (70). CBD also improved sleeping problems in children with autism spectrum disorder (ASD) (71) and in people with PTSD (54).

Nonetheless, researchers stress that “Research on cannabis and sleep is in its infancy and has yielded mixed results.” (68). Further research is needed.

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. 

Multiple studies have demonstrated that CBD can protect neurons (neuroprotection). Here’s a look at the main findings:

  • In one high-quality clinical trial, CBD improved the quality of life of Parkinson’s disease (PD) sufferers (72)
  • In a similar study, CBD improved psychosis in people with PD (73)
  • A pilot study of people with severe dementia found that 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)
  • Research in mice found that CBD reversed and prevented cognitive deficits in mice with Alzeimer’s disease (AD) (75)
  • A similar study reported that CBD improved memory issues related to social recognition in mice with AD (76)

Cardiovascular Diseases

The application of CBD and other cannabinoids for heart and cardiovascular health is a relatively new area of research.

Early studies suggest that CBD may have multiple beneficial effects on your heart and 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 2007 study found that CBD protected coronary artery cells from damage caused by high blood sugar (78)
  • A 2010 study found that CBD had a positive effect on cardiomyopathy, a cardiovascular complication of diabetes (79)
  • A 2017 review of multiple 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)

Skin Disorders

Another area in which CBD holds much promise is skin conditions.

This isn’t all that surprising since the endocannabinoid system (ECS) is present in our skin.

In fact, there’s mounting evidence that the ECS plays a key role in skin health and its dysfunction may be linked to many common skin disorders and symptoms, including itching, acne, eczema, psoriasis, and even tumors (82, 83).

Here’s a look at the most notable findings:

  • In one study of 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 study of isolated human sebocytes (skin cells involved in acne) found that CBD lowered inflammation and sebum production, suggesting that it “has potential as a promising therapeutic agent for the treatment of acne vulgaris” (85).
  • In another test-tube study, CBD reduced the proliferation of keratinocytes, the process which plays the central role in causing psoriasis (86).

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 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).

In addition, several studies have demonstrated that CBD can protect mice from IBD (88, 89).


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 one, it can help reduce nausea, as demonstrated by studies in mice (91). 

More importantly, CBD can work in synergy with THC. For example, one study 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).

CBD has also been demonstrated to reduce pain in mice associated with Paclitaxel, a chemotherapy medication (93). In addition, CBD may help with cancer-related depression and anxiety.

On top of that, several studies have reported that CBD may have direct anticancer effects:

  • 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).
  • CBD may suppress the release of exosomes and microvesicles (EMV), biological 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 before we know for certain that CBD can counteract cancer directly.

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 one 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).
  • In a study of cannabis addiction, smoking strains high in CBD was associated with reduced cannabis dependence (104)
  • In a study of opioid addiction, people addicted to heroin had reduced cravings when taking CBD for 3 days, with the effects persisting for another week. There was no effect in the placebo group (105).
  • A case report of a 19-year-old woman with anxiety, depression, and insomnia linked to cannabis withdrawal found that CBD greatly reduced her symptoms (106). Similar results were reported in the case of a 16-year-old patient addicted to cocaine, MDMA, cannabis, and ecstasy. Here, CBD both improved symptoms and helped the teenager quit the drugs (58).

Furthermore, many health experts, including respected American neuroscientist Yasmin Hurd, believe that CBD 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 some other countries. 


Studies in mice suggest that CBD may be able to prevent the development of type 1 diabetes (108). 

On top of that, it might also have a positive effect on the multiple complications of diabetes, which include diabetic cardiomyopathy, retinopathy, and neuropathy (109, 110, 111).


Cannabis has a long history of use for migraines. Although CBD has yet to be examined in any human or animal study of migraines, there is some evidence that it may be beneficial.

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.


CBD may also help with psychosis, which can occur in schizophrenia and other mental disorders. In one study, CBD improved psychosis in schizophrenia patients as effectively as the prescription medication amisulpride. However, it did so with fewer side effects (113).

Another 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).

All in all, researchers believe CBD holds real promise in treating psychosis and other mental symptoms of schizophrenia (115).


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

  • 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 paper reported on the benefits of CBD-rich cannabis extract (30% CBD, 1.5% THC) in 188 children with autism, with most study participants having a moderate-to-significant improvement in multiple symptoms, including seizures, depression, and restlessness (118).

Workout Benefits

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

  • Speeding up muscle recovery and improving delayed-onset muscle soreness (DOMS) through its anti-inflammatory erffects (120)
  • Relieving pain from overuse, injuries, and other causes
  • Protecting against concussions and other forms of brain trauma, which is common in contact sports
  • Supporting healthy sleep, which is needed for optimal recovery
  • Supporting bone and cardiovascular health
  • Easing muscle spasms (121)
  • Reducing nausea and potentially other digestive issues, which can help with recovery (35)
  • Reducing performance anxiety

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 claiming that CBD can help you lose weight. Having said that, there is some interesting early research suggesting that CBD may reduce appetite and have other weight loss benefits.

The most promising study was done by Korean researchers in 2016.

They applied CBD to mouse adipocytes (fat cells) and found that it “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).

A brown fat cell.

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.” 

Aside from that, two studies in rats have found that CBD can reduce appetite and body weight (123, 124). However, these results should be interpreted with caution because the doses used were quite large. 

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).


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

CBD and 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). 

Bone cells also contain GRP55 and TRPV1 receptors, which we discussed earlier as one of the molecular targets of CBD. 

This means that CBD can have beneficial effects on your bones. For example, one study found that CBD promoted the healing of fractures in rats and improved bone strength (133). 

The researchers believe CBD achieved this by supporting an enzyme involved in keeping your bones healthy and strong. 

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).

These findings suggest that CBD could help with osteoporosis, fractures, and other bone conditions characterized by loss of bone mass.

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.

MethodAbsorptionTime to Feel EffectsAverage DurationProduct Types
SublingualMedium-High10-30 min4-6 hoursCBD oil, spray, isolate
OralLow30-120 min4-8 hoursCBD capsules, edibles, drinks
InhalationMedium-HighSeconds1-4 hoursCBD vape e-liquid, CBD hemp flower
TopicalMedium10-60 min2+ hoursCBD 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.

fab cbd nighttime gummies

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. 


lazarus naturals high potency full spectrum cbd tincture

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. Learn more about the differences between CBD capsules and softgels.

CBD Gummies and Other Edibles

r&r cbd gummies

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

kiara naturals cbd salve

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 concentrate 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

cbdfx chill shot

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.


endoca 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.

This video from the CBD company Endoca is a great summary of the CBD extraction process.

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 DoseMedium DoseHigh Dose
100 lbs10 mg30 mg60 mg
125 lbs13 mg38 mg75 mg
150 lbs15 mg45 mg90 mg
175 lbs17 mg52 mg105 mg
200 lbs20 mg60 mg120 mg
225 lbs22 mg67 mg135 mg
250 lbs25 mg75 mg150 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: 40+ 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.

An example of a third-party CBD CoA document showing the cannabinoid profile of a full-spectrum CBD oil. Note the high CBD levels and the presence of other cannabinoids.

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 and, 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 just want the best overall effects, go with 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.


Leave a Comment