A peptide COA is only worth reading for two numbers: identity and dose. Identity confirms the vial holds the labeled compound; dose confirms how much is actually in it. The endotoxin, sterility, and heavy-metal panels suppliers flex are mostly optional - and the founder of the biggest testing lab in the space says so himself.
*Last updated: July 2026 - BodyHackGuide research desk*
This is the single most argued-about question in our r/BodyHackGuide community on Reddit, so instead of adding another opinion we went to the source that actually runs the tests.
What is a peptide COA?
A certificate of analysis (COA) is a lab report on a specific batch of a compound. For research peptides it typically lists purity by HPLC, identity by mass spec, and a set of optional add-on panels: endotoxin, sterility, heavy metals, residual solvents. Sellers post them as proof a vial is legit. The problem is that most buyers grade the wrong parts of the sheet.
The only two numbers that matter: identity and dose
If you read nothing else on a COA, read these two.
Identity answers "is this even the right molecule?" Mass spec confirms the molecular weight matches the labeled peptide. One catch almost nobody mentions: HPLC purity and mass spec do not fully confirm the amino-acid sequence, so a peptide missing a single amino acid can read 99% pure and still be the wrong compound.
Dose answers "did I get the amount I paid for?" A vial labeled 5mg that actually holds 3mg is the single most common way this market shorts people, and it is invisible unless the lab quantifies the real milligrams.
Peter Magic, founder of Janoshik Analytical (the most-used testing lab in the space), put it plainly on the Peptide of the Week podcast: "the best value test by far is the identity and the dose... everything else is rather optional."
Why endotoxin, sterility, and heavy-metal tests are mostly theater
Here is the part sellers do not want framed this way. The person who could charge you for every one of those add-on panels is the one calling them low value. In his words: "naturally it would be good for my business to tell everyone how important this testing is. and most of it is completely useless."
Heavy metals is the clearest example. Metals are not part of how peptides are made, so there is no route for them to get in. Janoshik has tested thousands of vials and, per Magic, has not had a single heavy-metal positive. The reason a test ever flags something is that the instrument used (ICP-MS) is sensitive enough to detect a trace of almost anything. His example: you could detect uranium in your drinking water, and it still would not be at a level that harms you. When a lab advertises that "60% of tested peptides contain heavy metals," that is a sales tactic, not a safety warning, because the levels are nowhere near dangerous.
When endotoxin testing actually matters
Endotoxin is the honest exception, and it is worth understanding because it is the one add-on that can catch a real problem.
Endotoxins come from bacterial cell walls. Old-school peptides like human growth hormone were grown in E. coli bacteria, so endotoxin contamination was a genuine risk. Modern research peptides are made by solid-phase synthesis, which has nothing to do with bacteria, so endotoxin should be a non-issue.
Magic originally said endotoxin testing was pointless for that reason, then reversed himself on the record: his lab started seeing samples that came back badly contaminated, from people reporting real local reactions (swelling, itching, pain). His takeaway was blunt: he was wrong, and endotoxin can matter for injected material. Sterility follows the same logic if you are actually injecting. So these are not zero, they are just far down the priority list behind identity and dose.
How bad is the market, really?
Bad enough that identity and dose are not a formality. Per Magic's own count, roughly 1 in 20 samples he tests is either the completely wrong compound or has nothing usable in it at all. During one recent three-week stretch, large distributors sent him around 600 samples that came back empty. Most never reach buyers because the distributor tests and rejects the batch, which is exactly the point: testing for identity and dose is what catches this.
How to read a COA in 60 seconds
- Find the identity result. Confirm mass spec matches the labeled compound. No identity, no deal.
- Find the quantification (dose). Look for actual milligrams measured, not just the number printed on the vial.
- Check HPLC purity %. Higher is better, but remember purity does not prove the sequence, so it sits under identity.
- Treat endotoxin and sterility as bonuses, relevant mainly if you are injecting finished material.
- Ignore the "7x tested / 20x tested" badge count. More panels is marketing, not proof.
- Verify the lab. A named, reputable testing lab and a batch-specific report beat a wall of green checkmarks.
Red flags on a COA
- Only endotoxin, sterility, and heavy-metal checkmarks shown, with no HPLC purity % or dose quantification.
- "Injectable grade" stamped on a vial with no real endotoxin number behind it.
- A COA with no testing lab named, or one you cannot verify against the lab's own database.
- Recycled or AI-generated graphs (a growing problem the labs themselves flag).
Test-by-test: what each one actually tells you
| Test | What it confirms | How much it matters |
|---|---|---|
| Identity (mass spec) | It is the right molecule | Critical |
| Dose / quantification | You got the amount claimed | Critical |
| HPLC purity % | Fraction that is the target compound | High (but not a sequence check) |
| Endotoxin | Bacterial contamination | Situational, matters for injectables |
| Sterility | Microbial contamination | Situational, matters for injectables |
| Heavy metals | Trace metal contamination | Low, essentially never an issue for peptides |
| Residual solvents | Leftover synthesis solvents | Low for most buyers |
The bottom line
The whole point is that identity and dose are the only numbers that decide whether you got what you paid for. That is exactly why every batch at BHG Labs ships with a batch-specific identity and dose COA you can actually read, no wall of decorative checkmarks. Same reason we built a free reconstitution calculator to handle the dosing math, and a compound wiki that breaks down what each peptide does before you ever open a COA.
*Sources: Peter Magic (founder, Janoshik Analytical) on the Peptide of the Week podcast; FDA guidance on bacterial endotoxins and pyrogens. For research and educational purposes only. None of this is medical advice.*
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