Peptide Testing Labs
How to read a COA, verify it, and spot the red flags
Research peptides are not checked for identity, purity, or content the way approved medications are — so independent lab reports (a Certificate of Analysis, or COA) are how the community judges quality. This guide explains what those reports measure, how to read a Janoshik-style result, and how to confirm a report is genuine rather than faked.
Why independent peptide testing exists
Because research peptides sit outside the approved-medication supply chain, nobody guarantees that a vial labeled "10 mg retatrutide, 99% pure" actually contains that molecule, that amount, or that purity. Third-party laboratories fill the gap by independently analyzing a sample and publishing a Certificate of Analysis (COA) — a document the community uses to sanity-check what is in a vial.
A COA does not make a product safe or legal, and it does not replace medical advice. What it does is give you objective data — identity, purity, and quantity — so you are not relying on a seller’s word alone. Reading one correctly is a basic harm-reduction skill.
What a peptide test report measures
| Test | What it measures | Why it matters |
|---|---|---|
| Mass spectrometry (identity) | The molecule’s exact mass | Confirms the vial actually contains the labeled peptide, not a cheaper substituteBest |
| HPLC purity (%) | Share of the sample that is the target peptide | Higher purity means fewer impurities and by-products; many look for 95%+ |
| Quantification (content) | Actual mg of peptide vs the labeled amount | Under-filled vials are common — this confirms you are dosing what you think |
| Sterility / endotoxin | Microbial and bacterial-endotoxin contamination | Most relevant for injectables; high endotoxin can trigger reactions |
How to read a Janoshik-style report
Janoshik Analytical is one of the most commonly referenced peptide-testing labs, so many community reports follow its format. Start with the peptide name and the measured mass — they should match the expected molecular weight for that peptide. Next, read the purity percentage (the proportion that is the intended molecule) and the quantification (how many mg were actually found versus the label).
A typical "good" result shows the correct identity, a high purity figure, and a content close to the labeled amount. A vial labeled 10 mg that quantifies at 6 mg is under-dosed by 40% — useful to know before you reconstitute, because it changes your real concentration and unit math.
How to verify a test report is genuine
Red flags in a peptide COA
Signs a report is faked, cherry-picked, or not actually about your vial.
After you read the report: dose math and tracking
Once you trust the identity and content, the practical next step is the math: the measured mg (not just the label) sets your true concentration after reconstitution, which sets your dose in syringe units. Use the reconstitution and syringe calculators to convert accurately, and log your vial’s tested values so future doses stay consistent.
This guide is educational and about quality verification, not sourcing. Research peptides are not approved medications; decisions about whether to use them belong with a qualified healthcare professional.
Guide FAQs
Check three things: identity (the measured mass matches the peptide’s expected molecular weight), purity (the percentage that is the intended molecule, often 95%+), and quantification (actual mg found versus the labeled amount). A good report shows the right molecule, high purity, and content close to the label.
Use the report’s unique order/verification code on Janoshik’s official verify portal and confirm the peptide, batch, date, and values match what you were shown. Screenshots can be edited; the portal cannot. No verifiable code means the report is unverified.
A Certificate of Analysis typically reports identity (mass spectrometry), purity (HPLC %), and quantification (actual mg). Some also include sterility or endotoxin testing for injectables. It reflects the tested sample, not necessarily every vial in a batch.
Many in the research community look for 95%+ purity, with higher being better, but purity alone is not enough — content (actual mg vs label) and verified identity matter just as much. A high-purity vial that is under-filled still changes your dosing.
At-home kits are generally less reliable than accredited lab analysis (mass spec + HPLC). They can be a rough screen, but a verifiable third-party COA is the stronger signal for identity, purity, and content.
Yes. Shotlee lets you store each vial’s tested content and concentration, then log doses and side effects against it, free — so your real (tested) numbers drive your dose math.
Log Your Tested Vials in Shotlee
Store tested content and concentration, then track every dose against your real numbers — free.