How to Read a CBD Lab Report (Certificate of Analysis): UK Guide

A certificate of analysis (COA) is the lab report that shows what is actually in a CBD product. It is the single best way to check a seller’s claims, yet most people never open one. This guide walks through a real Hemp Hub COA line by line so you know exactly what to look for.

What a CBD certificate of analysis is

A COA is issued by a testing laboratory after it analyses a sample from a specific production batch. It lists each cannabinoid the lab measured and how much of it was found. A trustworthy COA is issued by an independent lab, not by the brand itself, and its batch number matches the product you are holding.

The six things to check on any COA

1. Who tested it, and are they accredited?

Look for the lab’s name, address and accreditation at the bottom of the certificate. ISO/IEC 17025 is the international standard for testing and calibration laboratories; accreditation means the lab’s methods and competence have been independently assessed. Every Hemp Hub product is tested by ADACT Medical Ltd in Doncaster, an ISO/IEC 17025:2017 accredited laboratory.

2. Does the batch number match your product?

A COA only describes the batch it tested. Check that the batch or sample ID on the certificate (for example HOR-010 for our Horizon CBD Resin) matches the product page or packaging. A generic COA with no batch number tells you very little.

3. Which test method was used?

Most cannabinoid potency tests use HPLC (high-performance liquid chromatography), often written as HPLC-DAD or HPLC-UV. HPLC separates each cannabinoid so it can be measured on its own, and it measures the acid forms (such as CBDA) separately from the neutral forms (such as CBD).

4. Read the results column: % w/w

Results are usually given as a percentage by weight (% w/w). To turn this into milligrams, multiply by 10 for each gram. Horizon CBD Resin tested at 29.88% CBD, which is about 299mg of CBD per gram, or roughly 1,494mg in a 5g pack.

5. Understand ND, LOD and LOQ

• LOD (limit of detection): the smallest amount the lab’s method can detect.
• LOQ (limit of quantitation): the smallest amount it can measure accurately.
• ND (not detected): below the LOD, so the lab found none.
• <LOQ: present, but below the level the lab can measure precisely.

6. Check every cannabinoid, not just CBD

A good COA lists a full panel. Ours report 16 cannabinoids, including CBD, CBDA, CBG, CBGA, CBN, CBC and Δ9-THC. Looking at the full panel tells you whether a product is CBD-led, CBG-led or balanced, and whether marketing claims hold up.

Worked example: Horizon CBD Resin (batch HOR-010)

Cannabinoid	Result (% w/w)	What it means
CBD	29.88	The main cannabinoid: about 299mg per gram
CBDA	2.20	The acid precursor of CBD
CBGA	0.87	The acid precursor of CBG
CBG	0.31	A minor cannabinoid
CBC	0.11	A minor cannabinoid
Δ9-THC	<LOQ	Present below the measurable limit
THCV, CBN, CBL and others	ND	Not detected

Open the full Horizon certificate (PDF) and follow along.

Calculating total CBD

Because HPLC reports CBDA separately, labs and brands often quote a “total CBD” figure. The common formula is total CBD = CBD + (CBDA × 0.877). The 0.877 factor accounts for the weight lost when CBDA converts to CBD. For Horizon that gives 29.88 + (2.20 × 0.877) ≈ 31.8% total CBD. Hemp Hub quotes the measured CBD figure on product pages so the number matches the certificate exactly.

Red flags on a CBD lab report

• No lab name, address or accreditation.
• No batch number, or a batch number that does not match the product.
• A test date years older than the product.
• A COA that only lists one or two cannabinoids.
• Marketing claims (such as “30% CBG”) that the results table does not support.

Where to find Hemp Hub lab reports

Every current certificate is published on our Lab Reports page, and each product page includes its results table and a link to the PDF. Browse our CBD resins and extracts or hemp blends.

This guide is for general information only and is not medical or legal advice.