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How to Read a CBD Label and Certificate of Analysis (COA)

Check the product you have. As you tick off the items, you’ll see what’s missing.

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This list doesn’t show whether a product is safe or effective; it only shows how transparent the label is. For the rules on selling CBD in Turkey, see the regulation page.

How to read a certificate of analysis (COA), step by step

  1. 1. Check who prepared the document

    The top of the document should show the laboratory’s name, address and accreditation number (e.g., ISO/IEC 17025). The laboratory should be independent of the manufacturer. The name or signature of the person who approved the document should also be there.

  2. 2. Match the batch number

    The batch/lot or sample number on the document should be the same as the number on your bottle. The product name and type (oil, capsule) should also match. If they don’t match, the document tells you nothing about your bottle.

  3. 3. Check the dates

    Find the sampling date and the date of analysis. The analysis should have been done close to when the product was made. Don’t trust a document that is undated or very old.

  4. 4. Understand the units

    Results may be given in mg/g, mg/ml or as a percentage (%). Convert them to the same unit before comparing them with the label. If you’re not sure, ask your pharmacist for help.

  5. 5. Check the amount of CBD

    Look at the “total CBD” line; this line takes CBDA into account in addition to CBD. If the amount found differs from the label by more than 10%, research counts the product as mislabeled.

  6. 6. Read the THC lines

    Look at the Δ9-THC, THCA and “total THC” lines; THCA can convert to THC with heat. “ND” (not detected) does not mean zero; look at the limit of detection or quantification (LOD/LOQ) next to it.

  7. 7. Look at the other cannabinoids

    This table shows whether the full-spectrum, broad-spectrum or isolate claim holds. An isolate should contain no significant cannabinoid other than CBD; in a broad-spectrum product, THC should be “ND.” If you are an athlete, check substances such as CBG and CBDV against the current doping list.

  8. 8. Check the contaminant tests

    There should be separate tables for heavy metals (lead, arsenic, cadmium, mercury), pesticides and residual solvents. Each line should show the limit value and a “pass/fail” result. If these sections are missing, the document is incomplete.

Warning signs

  • The label or seller claims the product cures a disease (cancer, autism, epilepsy, etc.) or replaces medicine.
  • Phrases such as “no side effects,” “safe for everyone” or “100% natural, harmless” are used.
  • There is no certificate of analysis (COA), or it isn’t provided when you ask.
  • There is no batch (lot) number on the bottle or box.
  • The batch number on the COA doesn’t match the one on the bottle, or the document belongs to another product.
  • The label says “hemp oil,” “hemp extract” or “cannabinoids” but doesn’t state how many mg of CBD are in the bottle.
  • Use is described only by number of drops; it doesn’t say how many mg of CBD are in 1 ml or 1 drop.
  • The COA doesn’t show the laboratory’s name, address or accreditation details, or the document comes from the manufacturer’s own lab.
  • The COA shows only CBD; there are no THC or contaminant (heavy metal, pesticide, solvent) tests.
  • The product says “THC-free” but the COA has no THC measurement.
  • The COA is undated or very old; the bottle has no expiration date.
  • The carrier oil, ingredients or manufacturer contact details are not listed.

Frequently asked questions

Is a product with a certificate of analysis (COA) safe?

Not on its own. A COA only means something if it comes from an accredited laboratory independent of the manufacturer, carries the batch number of the bottle in your hand, and includes contaminant tests along with CBD and THC. In one study, the label accuracy of products that said “tested by an independent lab” was no different from those that didn’t. Your doctor decides whether the product is right for you.

Can I trust the amount of CBD on the label?

Not always. In most studies, fewer than half of products had a CBD amount that matched the label: 31% of 84 products in the US, 38% of 29 products in the UK, and 54% of 80 products in the US. The gap goes both ways: some products have less CBD than stated, others more. In a regulated market (Canada), 90% of CBD labels were within tolerance, but 40% of THC labels were outside tolerance.

Are hemp seed oil and CBD oil the same thing?

No. Hemp seed oil is a cooking oil pressed from the seeds. According to the FDA, the seeds do not naturally contain CBD or THC; trace amounts may be picked up during processing. In 20 seed oils sold in Turkey, CBD was at most about 0.02 mg per ml; in the same study, trace THC was detected in all but one sample. If the bottle doesn’t say how many mg of CBD it contains, don’t count the product as CBD oil.

Can a product labeled “THC-free” cause a positive urine test?

A positive result is not expected with pure CBD: none of 218 urine samples collected after 100 mg of pure CBD tested positive on confirmatory testing. However, CBD products containing small amounts of THC did cause positive results, and THC was found in some products labeled “THC-free.” If you will be tested, check the THC result and the limit of quantification on the COA, and talk to your doctor.

What is the difference between a prescription CBD medicine and CBD oil bought online?

The approved CBD medicine (Epidiolex/Epidyolex) contains purified CBD, and each ml is known to contain 100 mg of CBD. Its effects and side effects were studied in double-blind, placebo-controlled trials; its label lists the dose, interactions and liver test monitoring. In unregulated products, the contents often don’t match the label, and THC or contaminants may be present. To find out which products can be sold in Turkey and under what conditions, see our page on regulation in Turkey.

What should I bring to my doctor about the product I use?

Bring the bottle or a photo showing the label and batch number, the certificate of analysis for the same batch, a list of all the medicines you take, and how many mg of CBD you take a day. Because CBD can change the blood levels of some medicines, your doctor may order liver tests or drug levels. The personal warnings tool on this site prepares a summary you can take to your doctor.

Sources

Show 26 references

Trusted sources from around the world

Show 3 references
  • FDA: Warning letters sent to CBD productsUS Food and Drug Administration (FDA), English

    Warnings sent about CBD products sold with claims to treat diseases, and some product test results.

  • UK FSA: CBD products listUK Food Standards Agency (FSA), English

    A public, searchable list of CBD products going through the authorization process for sale in the UK.

  • ConsumerLab: CBD product testsConsumerLab (independent testing organization), English, August 2026

    Lab testing of the amount of CBD and THC in CBD products on the market. Most results are available to members only (paid).

These sources sell no products. All trusted sources