How to Read a Supplement COA: Our Own Certificate, Line by Line

To read a supplement certificate of analysis, check five things in order: who issued it, the lot number, the method beside each result, the result against its limit, and what was never tested. Below, we read our own certificate that way — including the fine print.

This page is a satellite of how to choose a beef organ supplement. That guide says a certificate beats a “third-party tested” sentence; this one shows what to do with the certificate once you have it open.

What is a certificate of analysis, and what is not one?

A certificate of analysis is a document that names the test method used, the limit for each test and the actual result, for one identified lot. Those three elements are what the FDA’s manufacturing rule requires of a certificate a manufacturer relies on, and a page that carries none of them is describing testing, not showing it.

The definition follows the FDA’s compliance guide to 21 CFR Part 111, read 16 September 2026, which lists those three elements under 111.75(a)(2)(ii)(B). Three other documents get mistaken for one. A supplier specification states what a material is supposed to meet, before any batch is tested; our New Zealand ovary document is one, and our Lab Tests page labels it as such. A facility certificate — ours is NSF/ANSI 455-2 — covers the plant, not any batch. And “third-party tested” is a sentence with no lot, no method and no number.

Who issued the certificate, and why does it matter?

The letterhead tells you whose measurement you are trusting. Our finished-product certificate for lot 0125252 was issued by Makers Nutrition, the contract manufacturer that filled the capsules, and signed by its quality assurance associate. The only independent document we publish is the allergen screen by Contract Testing Laboratories of America, an outside laboratory with no stake in the result.

Neither is a flaw; what matters is telling them apart. A manufacturer’s certificate is the release record for the batch — it is how the plant decided the lot could ship. An outside laboratory’s report answers the narrower question a customer paid to ask. We name both because our audit of 59 beef organ supplements found that 21 publish any certificate at all, and among products marketed to women, 4 of 16. The NIH Office of Dietary Supplements adds the caution that quality seals from outside organizations indicate a product was properly made and contains what the label says — not that it is safe or effective. The same limit applies to any certificate, ours included.

What do the lot number and the fine print tell you?

A certificate covers the lot printed on it and nothing else. Ours reads product code BN-C412, lot 0125252, manufactured 10/2025 — the number to match against the bottom of your bottle. The allergen report carries its own fine print: the results represent the sample submitted and do not constitute a guarantee of quality for the entire product it was taken from.

That is standard laboratory language, worth taking literally. Under the FDA rule a manufacturer must verify that a subset of finished batches, chosen by a statistical sampling plan, meets its specifications — or test every batch. So one published certificate proves one lot was tested; it does not by itself show that every lot is. If the lot on your bottle is not the one on our page, ask us for that lot’s document. A certificate with no lot number at all is not a certificate of analysis.

Why the dates differ from one document to the next

The allergen sample was received on 30 October 2025 and reported on 7 November; the finished-product certificate carries the October 2025 manufacturing month; each New Zealand organ document is dated when that consignment was released. Separate materials, separate tests, separate dates — one document covering all of them would mean one party vouching for everyone else’s work.

How do you read the assay line against the label claim?

On lot 0125252 the five organs and the collagen each measured 100.00 percent of label claim by FTIR; biotin measured 11.64 mg against a 10.00 mg claim by HPLC (116.4 percent) and zinc 13.83 mg against 10.00 mg by ICP-MS (138.3 percent), all inside the 100 to 150 percent specification each line must meet.

Results above 100 percent are how the rule is written, not a mistake: 21 CFR 101.36(f)(1) requires an added vitamin or mineral to be present at no less than the label amount and accepts reasonable excesses within good manufacturing practice, so manufacturers formulate above the claim to stay above it through shelf life. The 13.83 mg of zinc remains well under the 40 mg a day upper limit in the NIH zinc fact sheet; biotin has no established upper limit. A result below 100 percent is the line that fails. The method column matters too. FTIR compares a powder’s infrared fingerprint and reports how much of that material is present against the claim — it says nothing about the vitamin A, B12 or iron inside the powder, which is why we print no nutrient figures for our organs on the Supplement Facts page. Two lines are easy to skip: weight variation, 670.00 mg per capsule against a 692.92 mg target, ±10 percent, and disintegration, 23 minutes in sodium acetate buffer.

What do “less than”, MDL and NMT mean on a certificate?

“Less than” means not detected above the method’s floor, not zero. Our allergen report shows gluten at less than 4 ppm beside a method detection limit of 4 ppm; the specification column says “Report”, meaning no pass-or-fail limit was set and the number is simply stated. NMT means “not more than” — the ceiling a result must stay under.

So the gluten line reads: tested by ELISA, nothing found down to 4 parts per million, against the 20 ppm threshold the FDA sets for a “gluten-free” claim — the document our gluten-free page rests on. The heavy-metal panel has two floors. Arsenic came back at 0.216 mcg per unit and cadmium at 0.091, each against a limit of NMT 3; lead read below the limit of quantification, 0.010, and mercury below the limit of detection — measured but too small to put a number on. Microbiology is a count: 140 colony-forming units per gram of total aerobic bacteria against a limit of 10,000, yeast and mold under 10 against 1,000, and Salmonella, E. coli and S. aureus absent, by USP methods 2021 and 2022. One footnote deserves attention on any certificate: the allergen report says its specifications were provided by the customer. A limit is only as strict as the specification someone wrote.

What does a certificate of analysis not tell you?

It tells you what was measured in one lot, and nothing about what was not. Ours has no pesticide or glyphosate panel; the five New Zealand organ documents are supplier specifications, not assays we commissioned; and no line on any certificate says whether the product does anything — a certificate measures what is in the capsule, never what it does.

The gaps are the reason to read one at all. A 2022 case series in JAMA Network Open (Crawford and colleagues, PubMed 35947382) analyzed 30 immune-support supplements bought on Amazon: 13 had accurate labels; of the other 17, 13 listed ingredients that were not detected and 9 contained substances not on the label; none carried a third-party seal. Immune products, not organ supplements, and a small sample; the point survives. A label is a claim; a certificate is where someone measured it. Why publishing the test is a choice rather than a duty is in the complete guide. And 100 percent of claim says nothing about whether 150 mg of an organ matters — no controlled trial has tested a multi-organ product, ours included.

The short version

How to read a supplement COA comes down to five checks. Who issued it — a contract manufacturer’s release certificate and an outside laboratory’s report are different documents, legitimate as long as you can tell which is which. The lot number, matched to your bottle. The method beside each result. The result against its limit — above 100 percent of claim is by design, below is a failure, “less than” means below the floor, NMT is the ceiling. And what was never tested. Women Bloom publishes eight documents on one page, says which are certificates and which are specifications, and names who signed the finished-product certificate — because the reading only works if the paperwork is there to read.*

Last reviewed: 16 September 2026. Certificate values are transcribed from the Makers Nutrition finished-product certificate of analysis and the Contract Testing Laboratories of America allergen report for lot 0125252, both reproduced on our Lab Tests page. Regulatory references: FDA Small Entity Compliance Guide to 21 CFR Part 111, 21 CFR 101.36(f)(1) and 21 CFR 101.91, read 16 September 2026. This article is general information, not medical advice. Talk to your physician or a registered dietitian before starting any supplement.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.