How to Identify Certified CBD Products and What to Avoid

Independent tests of CBD products in Europe and the US repeatedly uncover the same issue: a large proportion of products on the market don’t contain what they claim on the label. Some have significantly less CBD, others more THC than is legal, and in a few cases heavy metals or solvent residues from extraction have been found.

The good news is that this is avoidable. There is one document that tells you almost everything — and a few label signals that reveal the rest.

The COA certificate: the document that decides

COA stands for Certificate of Analysis — a laboratory report for a specific production batch. An independent laboratory takes a sample of the product, tests it and issues a protocol with precise numbers.

This is the only way to verify what’s in the bottle. Not the label, not the reviews, not the promises on the website. The certificate.

A quality seller publishes the COA, ideally directly next to the product or via a QR code on the packaging. If you can’t find it on their website and they don’t send it when asked, you have your answer — and it’s not a good one.

How to read a laboratory certificate

A COA looks like an incomprehensible table at first glance. In reality, you only need to check five things.

1. Does the CBD content match the label?

Find the CBD row and compare the value with what the packaging claims. If the bottle is 10 ml and declares 10% CBD, there should be approximately 1,000 mg of CBD.

A deviation of up to 10% is normal and acceptable — biological material is never exact to a decimal. A deviation above 20% is a warning sign.

2. Is the THC content within the limit?

The EU legal limit is 0.3% THC in the final product. On the certificate, look for the Delta-9 THC or Total THC row.

For broad-spectrum and isolate, the value should be ND (not detected) or <LOQ (below the limit of quantification). If you see a specific number, the product is not THC-free regardless of what it claims. We covered the differences between extract types in Full-Spectrum, Broad-Spectrum and Isolate.

3. Did they test for contaminants?

This is the section most people skip — and yet it’s the most important for your health. A quality COA includes tests for:

• Pesticides — hemp is a bioaccumulator that readily absorbs chemicals from the soil
• Heavy metals — lead, cadmium, mercury, arsenic; again from the soil
• Residual solvents — from extraction, if CO₂ method was not used
• Microbiology — moulds, yeasts, bacteria
• Mycotoxins — toxins from moulds

Each should show PASS or a value below the limit. If the certificate only contains a cannabinoid profile without contaminants, it is an incomplete test.

4. Who tested it and when?

The certificate must show a laboratory name — and that of a third-party laboratory, not the manufacturer’s internal department. Also check the test date. A certificate from 2022 on a product bought in 2026 proves nothing.

5. Does the batch number match?

The COA states a batch number (batch number or lot). The same number should be on your bottle. If they don’t match, they tested something else.

A detailed guide to reading lab results is also available at Prosper Wellness, which walks through each line of the certificate.

What to look for on the label

The certificate is the foundation, but the packaging itself reveals a lot. A quality product has on its label:

• CBD content in milligrams — not just “contains CBD” or “rich in hemp extract”
• Type of extract — full-spectrum, broad-spectrum or isolate
• Pack size — so you can calculate the concentration
• List of ingredients — including the carrier oil (MCT, hemp, olive)
• Country of origin of the hemp
• Manufacturing and expiry date
• Batch number
• Manufacturer contact — a real address, not just an email

Is any of this information missing? Consider a different product. Not because it’s necessarily bad — but because you can’t verify it.

Warning signs: what to avoid

Here is a list of things that should immediately raise a red flag.

No certificate or only “internal tests”

The biggest red flag of all. A manufacturer who stands behind their product has no reason to hide a certificate. Formulations like “tested in our laboratory” or “regularly checked” without a specific document mean nothing.

Miraculous promises

Cures cancer. Replaces medication. Eliminates anxiety in three days. A legal CBD product is a food supplement or cosmetic and cannot claim to treat or cure anything. Anyone who claims otherwise either doesn’t know the regulations or is deliberately ignoring them. Neither inspires confidence.

The US FDA regularly publishes warning letters to companies that sell CBD products with illegal health claims. It’s worth browsing those lists.

Suspiciously low price

Quality CBD extract has its price — CO₂ extraction, laboratory testing and certified raw materials all cost money. If you find a 10% oil for a few euros, either it contains virtually no CBD, or the manufacturer cut corners on testing.

Anonymous seller

A company with no traceable address, no history, stock photos of hemp and a contact form instead of a phone number. If something goes wrong, you have nobody to turn to. According to expert sources on fake CBD products, fictitious foreign companies are one of the most common signs of fraudulent brands.

Misleading “hemp oil” labelling

This is a classic trap. A product presents itself as a CBD oil but the ingredients list only hemp seed oil — which contains no CBD at all. It’s an entirely different product with a different value. We explain the difference in detail in Hemp Oil vs CBD Oil.

Percentages without milligrams

“Powerful 30% oil!” sounds great until you notice the bottle is 5 ml. Always calculate the total CBD in mg, not percentages — otherwise you can’t compare prices.

Quick checklist before buying

• Is the COA available and from a third-party laboratory?
• Does the batch number on the certificate match the one on the packaging?
• Does the CBD content match the label (within 10%)?
• Is the THC within the 0.3% limit (or ND for broad-spectrum)?
• Were pesticides, heavy metals and solvents also tested?
• Is the certificate less than a year old?
• Is the origin of the hemp and cultivation method stated?
• Does the manufacturer have a real address and history?
• Are claims about effects realistic?
• Does the price correspond to the CBD content?

If you can tick everything, you’re on safe ground.

How we do it

The hemp at our farm under the Kriváň peak is grown by hand, without pesticides or chemical fertilisers. Every batch undergoes an independent laboratory test and the certificate is available with every product.

The entire process from field to bottle is described on our CBD Production page — including the extraction method we use and why. Browse our full range in the CBD Oils category.

Frequently asked questions

Is a certificate legally required for every CBD product?

In the EU there is no single mandatory obligation to publish a COA for CBD products sold as food supplements. That makes it voluntary — which is precisely why it is such a good indicator of how seriously a manufacturer takes quality.

What does ND or <LOQ mean on a certificate?

ND = not detected, the substance was not found in the sample. LOQ = limit of quantification, meaning the value is below what the instrument can reliably measure. For THC in broad-spectrum products, both values are acceptable.

How do I know the certificate isn’t fake?

Check the laboratory — reputable labs have a website and accreditation. Some include a QR code or verification code on the certificate that lets you confirm the document directly with them.

Are good reviews on a shop enough?

No. Reviews can be purchased and reflect the buying experience, not the product’s composition. The certificate is the only thing that speaks to content.

Why is hemp so susceptible to contamination?

Hemp is a bioaccumulator — it absorbs heavy metals and chemicals from the soil more efficiently than most plants. It is even used to clean contaminated land. That’s why the soil where the plant grew matters more for CBD products than for most other crops.

Summary

Identifying certified CBD is not complicated once you know what to look for. The foundation is a laboratory certificate from an independent lab, with the correct batch number, a current date and a complete analysis including contaminants. The label should state the CBD content in milligrams, the type of extract, the origin of the hemp and the manufacturer’s contact details.

And above all — those who have nothing to hide, hide nothing. Transparency is the most reliable indicator of quality in the CBD market.

If you’d like help choosing the right concentration, see How to Dose CBD. For cosmetics, slightly different rules apply — we covered those in How to Choose a Reliable Brand of CBD Cosmetics.

Sources

• The Juice Warehouse, How to Identify High Quality CBD: Your Complete Quality Guide
• Treehouse CBD, How to Choose High Quality CBD Products: What to Look for on the Label
• Prosper Wellness, How to Read Your CBD Lab Results
• Skin Inc, 7 Tips to Avoid Fake CBD Products
• FDA, FDA Warns Companies Illegally Selling Food and Beverage Products That Contain CBD