CBD Third-Party Testing: Why It’s Important, Tips & More

By | Updated on January 12, 2024

Medically reviewed by
Kimberly Langdon

Evidence Based 5

Key takeaways:

  • Third-party testing refers to CBD companies sending their products to independent laboratories. These tests measure cannabinoid levels and check for contaminants to ensure safety and accuracy.
  • Third-party testing is the most important factor when shopping for CBD. It’s best to check the third-party test results before buying to at least make sure the CBD content matches the label.
  • Third-party tests help you find high-quality CBD products by showing the levels of minor cannabinoids and sometimes terpenes. Ideally, you want a minor cannabinoid content of over 10%.

The CBD market remains largely unregulated, so there are plenty of ineffective and potentially unsafe products.

Many don’t contain the advertised amount of CBD or other cannabinoids. Contaminants are an issue as well, with some products carrying heavy metals, pesticides, and other harmful substances. This is where third-party testing can help.

Reputable CBD brands send product samples to specialized labs for independent testing and share the test results on their website.

Keep reading to learn why third-party testing is important, the types of tests, how to read them, expert tips, and more. 

The Importance of Third-Party Testing

Third-party testing is essential when shopping for CBD because the industry is not strongly regulated. It’s easy for companies to lie about the potency of their CBD products or use low-quality, contaminated hemp to source their CBD extracts. 

Studies have consistently shown that many CBD products contain inaccurate CBD levels:

  1. One 2022 study of 80 CBD products found that nearly half were off from the label by more than 10% (1)
  2. Another 2022 study of 121 edible CBD products found that many were not only inaccurate but also contained heavy metals (2)

Third-party tests can help protect you by giving an unbiased look at the potency and purity of CBD products. They’re done by a lab unaffiliated with the company and should provide impartial results (more on that later). 

That’s why any CBD brand worth its salt pays an independent hemp testing lab to analyze its products and shares the resulting documents called certificates of analysis (CoAs) on its website. It’s an easy way to build trust with shoppers.

If the CoAs are unavailable, incomplete, or outdated by a few years, you should look for a different CBD company. 

What Do Third-Party Labs Test For?

Third-party labs can do various tests, each of which has to be run separately and has varying costs. These tests can be divided into two main categories:

  1. Potency tests, which measure the amounts of cannabinoids and terpenes
  2. Contaminant or purity tests, which check for the presence of various contaminants
Test TypeChecks For
Cannabinoid ProfileLevels of CBD and other cannabinoids
Terpene ProfileLevels of terpenes
Heavy MetalsHeavy metals like lead and arsenic
PesticidesCommon pesticides
Residual SolventsResidual solvents like ethanol
Microbiological ContaminantsMold, fungi, bacteria, and parasites
Other ContaminantsRodent feces, eggs, vitamin E acetate, & more

Cannabinoid Profile

The most common test a third-party lab runs is called a cannabinoid profile or potency test. This test shows the concentrations of individual cannabinoids, like CBD, THC, CBG, CBN, and CBDa.

First and foremost, this test helps confirm that you’re getting the right amount of CBD, which is usually the only cannabinoid with a labeled quantity. Second, it helps verify the levels of THC, which should be present in full-spectrum CBD products but not exceed 0.3%.

Thirdly, the profile test verifies that you’re getting proper broad-spectrum or full-spectrum CBD products by checking for the presence of minor cannabinoids like CBG, CBC, and CBN. If they’re not present or are found in very small quantities, then the product is either mislabeled or of low quality.

Example third-party test showing the cannabinoid profile findings.

Terpene Profile

A terpene or terpenoid profile test shows you the concentrations of terpenes, common plant compounds that are responsible for the unique aroma of cannabis, lemons, roses, lavender, pine trees, and other plants.

Research suggests that terpenes have a wide variety of beneficial properties, such as relaxing, sedative, and anti-inflammatory effects, and play an important role in the cannabis entourage effect (3).

Terpenes such as beta-caryophyllene, limonene, linalool, alpha-pinene, and humulene should be present in high-quality full-spectrum and broad-spectrum CBD products. 

Still, terpene profile testing is relatively rare because:

  • It’s only needed for full-spectrum and broad-spectrum products
  • Companies rarely make claims about terpenes
  • Most consumers don’t know much about terpenes
  • Terpenes are fragile, so it’s not easy to make CBD products with significant amounts; many companies would rather not do the test than show that their products contain little to no terpenes

Heavy Metals

Hemp is a bioaccumulator, which means it readily absorbs heavy metals and other contaminants from the soil (4). While this is great for phytoremediation — using plants to clean up contaminated soils — it’s not so helpful for making CBD products.

Third-party tests usually check for the heavy metals lead, cadmium, arsenic, and mercury, which are known to have negative health effects and can accumulate in hemp plants. That’s why third-party testing for heavy metals is important. 


Pesticides are often used in farming to control insects, weeds, and other unwanted pests. Although pesticides are not widely used in hemp cultivation, they can still find their way into hemp thanks to its bioaccumulating properties.

Like heavy metals, pesticides can be harmful to our health, so third-party tests check for a long list of potential pesticides (5). 

Residual Solvents

Solvents are compounds used to isolate CBD and other beneficial compounds from cannabis plants. A residual solvents test looks for leftover amounts.

This test isn’t as important for CBD because most brands use carbon dioxide (CO2) for extraction, which doesn’t leave behind any solvents or ethanol, which many people already consume in the form of alcoholic beverages.

Still, most CBD brands run a full panel of tests for potential residual solvents to give customers peace of mind. 

Microbiological Contaminants

Another type of purity test looks for microbiological contaminants, including mold, fungi, parasites, and bacteria, some of which can be harmful. For example, most labs test for salmonella bacteria and aspergillus molds. These tests will usually be labeled as “microbiological,” “mycotoxins,” or “bacterial.” 

Filth/Foreign Material

These tests check for the presence of unwanted foreign material, such as rodent feces, hairs, and insect eggs or parts.

How to Read Third-Party Test Results

When you open a third-party CoA document, you will see key details at the top, like the name of the lab and the CBD company, the tested product, and the date. Some CBD companies also add easy-to-read summaries of the test results and attach them at the top before the full CoA.

Cannabinoid Profile

To read a cannabinoid profile/potency test, look for the name of the cannabinoid; its concentration will typically be written as a percentage (of the total weight of the product) as well as milligrams (mg) per millimeter (ml) or gram (g).

Many labs will also list the total amount of CBD per package or unit and the sum of all cannabinoids to make things easier.

Sample third-party CoA with highlighted amounts of CBD, delta-9 THC, and total cannabinoids per 1 ml of CBD oil.

Terpene Profile

Meanwhile, when reading a terpene profile test, the main thing to look for is that there are multiple terpenes present. Alternatively, if the company makes claims about including specific terpenes in the product, you should be able to identify them on the test document.

Terpene profile with highlighted terpenes and their amounts.


Reading contaminant test results is relatively straightforward. Look for the name of the contaminant (like lead or salmonella) and whether it says pass or fail. Remember that some contaminants (like ethanol) are considered safe under certain levels, so a test might detect them but still give a pass.

Third-party heavy metals test highlighting the tested metals and the results.

Using Third-Party CoAs to Find High-Quality Products

The main goal of reading third-party tests is to ensure the product is safe and accurate. But here’s a pro tip — you can also use them to compare the quality of different CBD products.

The best example is when you’re looking for broad and full-spectrum CBD products, which can contain wildly different amounts of cannabinoids and terpenes. Let’s say you’re shopping for full-spectrum CBD oil — arguably the best all-around CBD product.

You might find two 2000 mg full-spectrum CBD tinctures from different brands.

But when you look at the third-party tests, one contains 400 mg (20%) of minor cannabinoids (THC and other non-CBD cannabinoids) and several terpenes, while the other one has only 100 mg (5%) of minor cannabinoids and zero terpenes.

The first tincture would have stronger and greater effects, making it the superior choice. 

I attached a screenshot below showing a similar real-life scenario with third-party test results for two full-spectrum CBD oils — you can see that the second oil contains more minor cannabinoids plus terpenes, making it the better option.

In my experience, tinctures that contain higher minor cannabinoid levels and terpenes are noticeably more effective, highlighting the power of the cannabis entourage effect. That’s why I always check the third-party CoAs for any product I’m testing or interested in buying.

I prefer full-spectrum products that contain at least 10% minor cannabinoids, but more is better.

How is Third-Party Testing Done?

Third-party testing is a rigorous process that requires specialized equipment and a team of educated lab technicians.

It’s a step-by-step process that involves receiving the CBD product sample, analyzing it, and reporting the results in a certificate of analysis (CoA) document, which the CBD company can then share with its customers.

Most third-party hemp testing labs use the following testing methods:

  1. High-performance liquid chromatography (HPLC) takes a liquid sample and separates out the substances inside it and detects their concentrations. This is usually the method used for cannabinoid profile testing.
  2. Gas chromatography (GC) is a variation of the above method that uses gas instead of liquid. It can be used for both cannabinoid and terpene profile testing but is more common for terpenes because they’re fragile. 
  3. Mass spectrometry (MS) ionizes a sample and tests it to determine the molecular weight, which tells you which compounds you’re dealing with. This method is mostly used to detect heavy metals and other contaminants and is often combined with chromatography.
  4. Polymerase chain reaction (PCR) testing checks for microbiological contaminants like bacteria and fungi. This is the same type of test used to detect COVID-19.
An HPLC machine I came across at the 2023 Bangkok Hemp Expo.

Lab Shopping and Lab Quality

One important caveat to keep in mind is that much like the CBD market it serves, the third-party lab industry is largely unregulated. Not all labs are trustworthy, and there is a monetary incentive for unscrupulous behavior.

In fact, one dirty secret of cannabis & CBD third-party testing is what’s known as “lab shopping.” It refers to companies sending their product samples to multiple labs and then choosing to work with those that give them the most favorable test results.

For example, one lab might correctly show that the company’s CBD products are inaccurate and contain heavy metals, while another will report high CBD levels and no contaminants.

In that situation, the brand might choose to work with the second lab, even if it’s using inaccurate testing methods or knowingly distorting the test results. This punishes honest labs and rewards bad ones and is an ongoing issue.

That’s why I recommend quickly checking the third-party lab used by your chosen CBD brand.

A simple Google search is usually enough to see if the lab can be trusted by looking at its website and customer reviews. Low-quality labs will typically reveal very little information about what they do and the people running the lab. 

You can also look for labs with the Trust In Testing certification, which was launched in 2023 by two leading labs to help promote testing quality and transparency.

Always Buy Third-Party Tested CBD Products

In conclusion, third-party testing is arguably the most important consideration when buying CBD products. Whether you’re shopping for CBD oil, gummies, capsules, topicals, vapes, or something else, independent testing helps ensure that you’re getting a safe, potent, and accurate product.

I recommend only buying from brands that provide up-to-date, comprehensive potency & contaminant third-party CoAs. If you want to be diligent, you can take the additional steps of checking the CoAs yourself and also Googling the third-party lab to see if it’s legitimate.

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