Short answer: the good ones do. A Certificate of Analysis (COA) is the single clearest sign a research-peptide vendor stands behind what it ships. Below is who publishes a public COA library, who sends reports on request, and which use independent third-party labs — on the facts, so you can verify before you order.
CD Biolab publishes a browsable public COA library — every batch documented with HPLC purity and mass-spec identity, purity figures shown per lot, and the report included with every order. If you want to see the paperwork before you commit, it is all on one page.
View CD Biolab's COA library → Shop CD Biolab →
Disclosure: CD Biolab is operated by the same team as Peptides Uncaged. We list it here on the same COA criteria we apply to every vendor.
Which companies provide a Certificate of Analysis, what kind of testing backs it, and whether it's public or on request. "Read review" opens our full breakdown; "View / Shop" opens the vendor.
| Company | COA provided? | Testing | Availability | ||
|---|---|---|---|---|---|
| CD BiolabPublic library | ✓ Yes | HPLC + mass spec | Public, every batch | View COAs | Shop |
| Dynamic PeptidesReviewed | ✓ Yes | Independent HPLC + MS, ISO/GMP | Every product | Read review | Shop |
| Amino ClubReviewed | ✓ Yes | Third-party (ISO 17025) | Per-vial QR | Read review | Shop |
| Spartan PeptidesReviewed | ✓ Yes | HPLC + MS, named lab (MZ Biolabs), signed | Public, per product | Read review | Shop |
| Midwest PeptideReviewed | ✓ Yes | Third-party | Public, every product | Read review | Shop |
| GLP-1 Research LabReviewed | ✓ Yes | Certified US labs | Public, every batch | Read review | Shop |
| Ascension PeptidesReviewed | ✓ Yes | Multi-stage, third-party | Public library | Read review | Shop |
| ZestyRat ResearchReviewed | ● On request | Independent, 99%+ | Emailed on request | Read review | Shop |
| Pinnacle Peptide LabsReviewed | ● On request | Third-party (stated) | Not posted publicly | Read review | Shop |
"On request" isn't a strike against a vendor — a report that arrives by email still lets you verify your batch. A public library is simply more convenient and more transparent up front. Testing descriptions reflect each company's stated methods; always confirm the current COA on the vendor's own page. Last verified July 2026. For research use only — not for human consumption.
For balance: Modern Aminos is well regarded for per-vial QR-code COAs and a strong Trustpilot record, and Peptide Partners is frequently cited for documentation. We earn no commission on either — they're here on merit so this list stays honest.
Yes. The reputable ones publish a Certificate of Analysis showing HPLC purity and mass-spec identity for each batch. Some post a public COA library; others send the current report on request. A vendor that won't provide any COA is a red flag.
A lab document reporting a specific batch's purity, identity and related tests, tied to a lot number, so you can verify what's actually in the vial. See our guide to reading a COA.
CD Biolab, Dynamic Peptides, Amino Club, Spartan, Midwest, GLP-1 Research Lab and Ascension publish COAs; ZestyRat and Pinnacle provide them on request.
A third-party COA comes from an independent lab (e.g. Janoshik, MZ Biolabs) with no stake in the sale — the stronger signal. A manufacturer COA is made in-house. More in our note on third-party peptide testing.
Match the lot number to your vial, then check HPLC purity %, the mass-spec identity result, and the lab's name and date. See HPLC, mass spec & endotoxin testing.