Guide
How do you read a Certificate of Analysis?
By Jake, founder · Published · Updated
A Certificate of Analysis has four load-bearing parts: a header identifying the laboratory and its accreditation, sample identification tying the document to one product lot, a results table pairing each measured value with its specification and method, and the analyst's sign-off. Read it by checking identification first, then whether every result is an actual number.
A Certificate of Analysis is a laboratory's formal statement of what it measured in a specific sample. Reviewers, whether TIC providers, retailers or auditors, read COAs in a fixed order and reject them for a short list of mechanical reasons. Reading your own COAs the way a reviewer does is the cheapest quality control available.
1. The header: who measured, and on whose authority
The top of the document identifies the laboratory: name, address, contact details, and an accreditation reference, the identifier under which the lab is accredited to perform the reported methods. Reviewers use the contact details to confirm the document's authenticity directly with the lab, so a COA missing the lab's contact information or accreditation reference is commonly rejected before its results are even read.
2. Sample identification: which product, which lot, when
This section ties the paper to a physical batch. Expect the product name, the lot or batch code, the date the sample was received, and the date of the report. The lot code appears under many labels across labs (“Lot”, “Lot No.”, “Batch”, “Batch #”, “Lot/Batch Code”), but whatever the label, it must match the code printed on the product it is meant to cover. A COA is a per-lot document: results for one batch carry no authority for the next batch of the same product.
3. The results table: the part that is actually the COA
Every well-formed results table pairs six pieces of information per line:
| Column | What it contains | Why a reviewer needs it |
|---|---|---|
| Analyte | What was measured | Determines whether the required tests were run at all. |
| Result | The measured value | The substance of the document; everything else is context. |
| Unit | The unit of the result | A result without a unit is unverifiable; units must match the product label. |
| Specification / limit | The acceptance criterion applied | Shows what the result was judged against, and whose criterion it is. |
| Method | The analytical method used | Ties the result to an accredited, repeatable procedure. |
| Pass / fail | The lab's judgment | A summary only, never a substitute for the result itself. |
4. Non-detect notations, and the subtlety inside them
When a laboratory finds none of an analyte, the result is written as a non-detect. The notations vary: ND, BDL (below detection limit), Not Detected, or a less-than sign with the detection limit, such as “< [detection limit]”. These all mean the same thing: the method could not see the analyte below a certain concentration.
The subtle point reviewers check and sellers miss: a non-detect only demonstrates compliance if the method's detection limit is at or below the required limit. If a method cannot see below a level higher than the specification, “Not Detected” proves nothing about whether the product meets that specification: the analyte could be present anywhere between zero and the detection limit. When comparing a COA against a requirement, the detection limit, not the word “ND”, is what carries the argument.
5. Pass wording that is not a result
Some COAs fill the result column with “Conforms” or “Complies”. That is a judgment, not a measurement. It tells the reader that the lab was satisfied, not what was found. A reviewer verifying the document against an external requirement needs the number: the measured value, its unit, and the specification applied. COAs whose results are pass-words only are routinely bounced back for the underlying data, so ask the laboratory or manufacturer for the numeric version before a reviewer has to.
6. Multi-page continuation
Longer COAs continue across pages, and each continuation page should repeat the sample identification and page numbering (“page 2 of 4”). Verify you hold every page: a truncated COA, often the result of a bad scan or a partial email attachment, reads to a reviewer as missing results, and is treated as such.
What makes a COA unusable for verification
- Age. Older than the accepted window, the strictest reported figure being 182 days, regardless of content.
- Missing fields. No lot code, no dates, no lab contact details, no accreditation reference, or results without units.
- Wrong product version. Results for an expired or superseded formulation do not cover the product currently sold.
- Unit mismatch.Result units that do not correspond to the units on the product's supplement facts panel cannot be reconciled by a reviewer.
Document-age window applied here: 182 days, the strictest reported value; other sources report 274 and 365 days. Last verified 2026-07-24. This is provider policy, not regulation, so confirm the current figure with your TIC provider before relying on it.
Frequently asked questions
- What does ND mean on a Certificate of Analysis?
- ND means Not Detected: the laboratory looked for the analyte and found none above the method's detection limit. It appears in several forms: ND, BDL (below detection limit), 'Not Detected', or a less-than sign followed by the detection limit. A non-detect only demonstrates compliance if that detection limit is at or below the required limit.
- Is 'Conforms' or 'Complies' an acceptable result on a COA?
- Not for verification purposes. 'Conforms' and 'Complies' are the laboratory's pass/fail judgment, not a measured value. A reviewer verifying the document needs the number itself, with its unit, alongside the specification it was judged against.
- What makes a COA unusable for TIC verification?
- The common disqualifiers are age (older than the accepted window, the strictest reported figure being 182 days), missing fields such as lot code or lab contact details, results for an expired or superseded product version, and units that do not match the product's label.
- Does a COA cover a product or a specific lot?
- A specific lot. The sample identification section ties the results to one production batch via the lot or batch code. Results from one lot say nothing authoritative about another lot, which is why platforms and retailers ask for COAs per lot, not per product.