Guide · 7 min read
Is a peptide vendor legit? A COA checklist
You can't inspect a research-peptide vendor's lab, so their testing paperwork is most of the evidence you have. This checklist turns "is this vendor legit?" into questions you can actually answer from their COAs, with a simple way to score the result.
Disclosure: PeptideCOACheck earns a commission if you buy from Peplogix through our links. That doesn't change the checklist, and we suggest applying it to Peplogix exactly as you would to anyone else. We don't test products or rate vendors.
Why the COA is the right place to start
Website design, reviews and social media presence are easy to buy or fake. Testing evidence is harder to fake well and, importantly, it is checkable: you can match batch numbers, confirm reports with labs, and compare data across products. A vendor whose paperwork survives scrutiny isn't guaranteed to be honest, but a vendor whose paperwork falls apart has told you what you need to know.
The checklist
Score one point for each "yes". Work through a few different products, not just the vendor's best-sellers.
Availability: can you see the evidence?
- Is there a COA for every product? Not just a "lab tested" badge, but an actual report you can open.
- Is it batch-specific? The report shows a batch or lot number, and the vendor tells you which batch you'll receive (or prints it on the vial).
- Is the full report available? A complete PDF from the lab, not a cropped screenshot. See how to tell if a COA is fake.
- Is it recent? Tested within roughly the last 12 months, and refreshed when batches change.
Content: does the report prove anything?
- Is identity confirmed by mass spectrometry? HPLC alone shows purity, not identity. A credible report includes a mass that matches the compound's reference molecular weight.
- Is purity measured by HPLC with a chromatogram? A number with a chromatogram and peak table, not a bare "99%". See what a good HPLC purity is.
- Is content measured? Some reports state the measured amount per vial. That shows whether "10 mg" really is about 10 mg.
- Are method details shown? Column, detection wavelength, gradient or instrument. Real labs usually state them.
- Do the numbers make sense? No purity over 100%, no suspicious exact 100.0%, and a mass that isn't a better match for a different peptide.
Independence: who did the testing?
- Is the lab named and independent? A third-party lab with its own website and address, not the seller's "quality department". See third-party testing explained.
- Can the report be verified? A report ID, QR code or lookup on the lab's own domain, or a lab that confirms reports by email.
- Did verification actually match? Pick two or three reports and confirm them yourself. Score this point only if they all match.
Behavior: how does the vendor handle questions?
- Do they answer COA questions directly? Ask which batch you'd receive and for the matching report. A clear answer is a good sign. Deflection or hostility is not.
- Are COAs different across batches? Real data changes slightly from batch to batch. Identical chromatograms for different batches or compounds suggest recycling.
- Are claims limited to what the paperwork shows? Research-chemical vendors shouldn't make health or effect claims. Claims beyond the COA are a reason for more caution, not less.
Scoring
| Score | Reading |
|---|---|
| 13–15 | Strong, checkable evidence. Still verify the COA for the batch you actually receive. |
| 9–12 | Some solid evidence with gaps. Ask about the missing items before buying. |
| 5–8 | Weak evidence. You're mostly relying on trust. |
| 0–4 | Little or no verifiable testing. Treat products as untested. |
Some items count for more than others. A failed lab verification (item 12) or a mass that matches the wrong compound (items 5 and 9) should outweigh a high score elsewhere.
Scam patterns that a COA check catches
- The recycled report: one genuine COA from years ago, reused for every batch since. Batch numbers and dates give it away.
- The borrowed lab: a real lab's name and logo on a report the lab never issued. Lab verification catches it.
- The cropped screenshot: only the purity number is shown, never the batch, date or mass. Ask for the full PDF.
- The wrong peptide: the report's mass matches a cheaper, similar compound. Our checker flags masses that belong to another peptide.
- The perfect seller: every product at 99.9% or 100%, every time. Real data varies.
What a COA check can't tell you
Even a perfect score describes paperwork, not the vial in your hand. It can't detect a forgery that uses genuine-looking numbers and passes casual inspection, problems after testing such as storage or shipping, or anything about suitability for any use. Independent testing of your own sample is the only direct evidence, and nothing on this site is medical advice.
Check one of the vendor's COAs now. The checker scores mass, purity, date, lab and red flags.
Open the COA checker →Sources
- Janoshik help center: how reports can be verified: Example of how a lab confirms a report is genuine.
- PubChem (U.S. National Library of Medicine): Reference formulas and masses.
- PeptideCOACheck methodology: The rules the checker applies to each COA.
- PeptideCOACheck affiliate disclosure: How this site earns money.
Last updated . Written and maintained under our editorial policy. Found an error? See corrections.
Frequently asked questions
How can I tell if a peptide vendor is legit?
Look at its testing evidence. A credible vendor publishes a batch-specific COA for each product from a named independent lab, lets you verify the report with that lab, shows full chromatograms and mass spectra, and answers questions about batches. Then confirm a sample of its reports with the labs yourself.
Does having COAs mean a peptide vendor is legit?
No. COAs can be edited, recycled from older batches, or issued in-house. What matters is whether the COA matches your batch, comes from an independent lab, and can be verified with that lab.
What are signs of a peptide vendor scam?
Common warning signs include no COAs or only cropped images, one COA reused for many batches, labs you cannot find or contact, reports the named lab cannot confirm, prices far below everyone else, payment only by irreversible methods, and pressure to buy before you can ask questions.
Is this checklist a guarantee?
No. It reduces risk by focusing on evidence you can check, but no checklist can prove what is in a particular vial. Independent testing of your own sample is the only direct evidence.
Does PeptideCOACheck rate or approve vendors?
No. We do not test products, rate vendors or approve sellers. We earn a commission from one vendor, Peplogix, which is disclosed on every page. Apply the same checklist to them too; our Peplogix review shows how its COAs score on it.
Educational content only. Not medical advice. PeptideCOACheck does not rate, approve or endorse vendors. Research peptides are sold for laboratory research purposes only.