How to spot a fake COA in 60 seconds

The 60-second checklist

A certificate of analysis (COA) is a laboratory's report on a sample. For research peptides it is usually the only quality evidence a buyer ever sees, which is why it is also the document most often faked, recycled or misunderstood. The seven checks below are the same ones our COA Decoder applies when you paste a certificate into it ¹. Each takes a few seconds.

1. Is there a lot number and a test date? No lot number means the certificate cannot be tied to any batch; no date means you cannot tell whether the result is recent ¹.
2. Is purity a number from a named method? Look for an HPLC purity percentage. Missing is a red flag; below 95% is low; exactly 100% is not credible ¹.
3. Is the chromatogram attached? A purity figure without its chromatogram cannot be checked ¹.
4. Does the measured mass match the peptide? A mass spectrometry result is the identity check; purity alone says how clean the sample is, not what it is ¹.
5. Is endotoxin reported? Purity and mass say nothing about bacterial toxins ¹.
6. Who did the testing? A named laboratory stating ISO/IEC 17025 accreditation is a better sign than an unnamed one ^{1 2}.
7. Whose sample was it? A certificate on a sample the seller sent in describes that sample, not necessarily your vial.

The rest of this guide explains what each check catches and how fakes slip past people who skip it.

A worked example

Here is a short certificate of the kind sellers post, the same example our COA Decoder offers as its sample ¹:

CERTIFICATE OF ANALYSIS
Laboratory: Example Analytical Laboratory
Client: Sample Supplier
Product name: BPC-157
Lot number: EX-2026-0412
HPLC purity: 100.00%
Mass spectrometry: expected mass 1419.5 Da; observed m/z 710.8 ([M+2H]2+)

Run through the seven checks, it fails quickly. The purity is 100.00%, which no chromatographic method produces. There is no test date, no chromatogram and no endotoxin result, and no accreditation is stated. The one thing it gets right is the mass: an observed value of 710.8 matches BPC-157 as a doubly protonated ion, so the identity claim is at least consistent ¹. The decoder returns 3 red findings, one amber and one informational, alongside that single good result. A certificate like this does not prove the vial is bad. It proves the certificate cannot tell you whether it is good, and the matching mass is the easiest line of all to copy from a reference table.

Lot and date: the certificate has to belong to something

A real certificate describes one batch, tested on one date. The commonest fake is not a forged laboratory report but a recycled one: a genuine certificate from an old batch, or from a different product, attached to everything a seller lists. Without a lot number you cannot tell whether the certificate describes the batch you are buying, and without a date you cannot tell whether the result predates the batch altogether ¹. Peptides degrade, so even an honest result from two years ago says little about a vial made last month.

Check that the lot number on the certificate matches the one printed on the vial or its label. If the vial carries no lot number at all, no certificate can be shown to describe it.

Purity and the chromatogram: what 99% does and does not mean

HPLC purity is the share of the material that comes out of the column as the target peptide rather than as related peptides. The COA Decoder grades it the way buyers usually do: at or above 99% is high for a research peptide, 98 to 99% is typical, and 95 to 98% is lower, with the remainder made up of other peptides or impurities of unknown identity ¹. Below 95%, more than one part in twenty is something else.

A figure of exactly 100%, or 100.00%, should stop you. No chromatographic method measures a peptide as exactly 100% pure: there are always small impurity peaks, and a perfect number usually means the figure was typed rather than measured ¹. The chromatogram itself is the evidence behind the number. It is the trace of everything that came off the column, and it lets anyone see the impurity peaks and how the percentage was calculated. A certificate that quotes a purity figure but omits the chromatogram asks you to trust a number you cannot check ¹. Remember too that purity is not safety: our guide to what a COA rarely shows covers what HPLC cannot see.

The mass check you can do yourself

Purity says how clean a sample is; mass spectrometry says what it is. A highly pure sample of the wrong peptide is still the wrong peptide, so a certificate without a mass result has no identity check at all ¹. The good news is that this is the one number anyone can verify with arithmetic.

Mass spectrometers usually report protonated ions: the molecule plus one or more protons. For a single proton the reading is the molecular mass plus about 1.007; for two, it is the mass plus two protons, divided by two, and so on ¹. Take BPC-157, whose molecular weight in our encyclopedia is 1419.55 ³. A genuine result should show an ion near 1420.56 for one proton, or near 710.78 for two. The COA Decoder accepts a match within the larger of 1 dalton and 0.1% of the expected mass, here about 1.42, because average and monoisotopic masses differ slightly for larger peptides ¹. A reported mass that matches none of these, at any common charge, means the certificate does not describe BPC-157, whatever its title says.

Two cautions. A matching mass confirms identity, not quantity: it does not tell you how many milligrams are in the vial. And a mass can be copied from a reference table as easily as a purity figure, which is why the chromatogram, the lot and the laboratory still matter.

Endotoxin: the missing line on most certificates

Endotoxins are fragments of bacteria that cause fever and inflammation when injected, and neither purity nor mass testing detects them ¹. Approved injectable drugs are tested for endotoxin as a condition of release; most research-peptide certificates stop at purity and mass. A missing endotoxin result is not proof that a vial is contaminated, but it means no one has looked. When researchers bought semaglutide from illegal online pharmacies and tested it, every vial contained endotoxin ⁴.

The laboratory: names, accreditation and what to verify

ISO/IEC 17025 is the international standard for the competence of testing laboratories, and national accreditation bodies assess laboratories against it ². A certificate that names its laboratory and states 17025 accreditation for the method used is a better sign than one that does not, though the COA Decoder treats a missing statement as information rather than a red flag, because many legitimate certificates omit it ¹. The claim is only as good as its verification: accreditation is granted for specific methods, and accreditation bodies publish directories of the laboratories they accredit and the scope of each. Checking that the laboratory exists, is accredited and lists the relevant test takes longer than a minute, and it is the step that catches outright forgeries.

Be wary of certificates that carry no laboratory name at all, a laboratory that exists only as a logo, or contact details that lead back to the seller. A seller that tests its own products is not an independent laboratory.

Whose sample was it? The question a COA cannot answer

Here is the limit of every certificate, genuine or not: it describes the sample the laboratory received. If the seller chose and sent that sample, it may have been the best vial of the batch, a different batch, or a different product altogether. The only way to know what a seller actually ships is to test vials bought the way a customer buys them. Our database of published independent test results records who obtained each sample for exactly this reason. It currently holds 12 published results, all for semaglutide bought by researchers from illegal online pharmacies: 3 passed, 3 failed and 6 were inconclusive ⁵.

The study behind most of them shows why buyer-obtained testing matters. Researchers bought semaglutide from online sellers without a prescription; half of the orders never arrived. The vials that did were labelled as 99% pure. Measured purity was 7.7% to 14.4%, the semaglutide content was 28.6% to 38.7% higher than labelled, packaging failed most of a quality inspection, and every vial contained endotoxin ⁴. A certificate printed for those products would have described something else.

When a certificate fails the checks

A certificate that fails one or two checks is not automatically fraudulent; many legitimate laboratories issue short reports, and a missing accreditation statement is common ¹. But each failure removes a reason to believe the document, and some failures cannot be explained innocently. A purity of exactly 100%, a mass that matches nothing at any charge, a lot number that does not appear on the vial, or a laboratory that cannot be found are reasons to treat the certificate as unreliable, not as evidence of quality ¹.

Asking the seller for the missing parts, the chromatogram, the endotoxin result or the laboratory's details, is reasonable, and the answer is informative either way. What no request can fix is the sample problem: a better certificate is still a certificate on the seller's sample. If you are deciding whether to inject something, the honest summary is that a perfect certificate reduces some risks, removes none of the ones described in our article on serious reactions to injected peptides, and is never a substitute for a product made and tested under regulation.

Why fakes are common

Falsified peptide and protein drugs are a documented problem, not a hypothetical one. A Belgian national medicines laboratory's review describes seized products containing the wrong active ingredient, the wrong dose or none at all, toxic contaminants, and peptides that failed clinical trials or were never approved ⁶. A French toxicology laboratory that analysed 110 products seized from bodybuilders found that, of 75 pharmaceuticals, a third were substandard in dose and a third counterfeit in content, and only 19% matched their labels ⁷. A certificate is a cheap thing to produce next to that kind of operation.

That does not make every certificate worthless. It means a certificate is a claim, and the seven checks are a way of deciding how much of the claim you can check. Our page on what research use only means explains why none of it makes a research product an approved drug.

Frequently asked questions

How can I tell if a peptide COA is fake?

Check for a lot number and test date, a purity figure from a named method with its chromatogram, a mass that matches the peptide, an endotoxin result, a named and accredited laboratory, and who supplied the sample. A purity of exactly 100% or a mass that matches nothing are red flags.

What purity should a peptide COA show?

Research peptides are commonly sold at 98 to 99% HPLC purity; 99% or more is high, and below 95% means more than one part in twenty is something else. Exactly 100% is not credible.

What mass should a BPC-157 COA show?

Its molecular weight is about 1419.55, so mass spectrometry should show an ion near 1420.56 (one proton) or 710.78 (two protons), within about 1.4.

Does a real COA mean my vial is good?

Not necessarily. A certificate describes the sample the laboratory received. Only vials bought the way customers buy them show what a seller actually ships.

Related on Grey Peptides

• COA Decoder
• Verify hub
• Published independent test results

Sources

1. Grey Peptides COA Decoder rules (assets/coa-rules.json): 12 rules, purity grades, mass tolerance and protonated-ion handling. Read October 3, 2026.
2. International Organization for Standardization. ISO/IEC 17025:2017, General requirements for the competence of testing and calibration laboratories.
3. Grey Peptides encyclopedia: BPC-157 molecular weight 1419.55 (C62H98N16O22). Read October 3, 2026.
4. Ashraf, A. R., et al. (2024). Multifactor Quality and Safety Analysis of Semaglutide Products Sold by Online Sellers Without a Prescription: Market Surveillance, Content Analysis, and Product Purchase Evaluation Study. J Med Internet Res, 26, e65440. PMID: 39509151
5. Grey Peptides database of published independent test results (/verify/test-results/, _ops/lab_db.py). Read October 3, 2026.
6. Janvier, S., et al. (2018). Falsification of biotechnology drugs: current dangers and/or future disasters? J Pharm Biomed Anal, 161, 175-191. PMID: 30165334
7. Fabresse, N., et al. (2021). Analysis of pharmaceutical products and dietary supplements seized from the black market among bodybuilders. Forensic Sci Int, 322, 110771. PMID: 33838562

Educational information, not medical advice. Each dose in this guide names its source, an approved label or a published study. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose.