Semaglutide COA: how to read one — and spot a fake.

Semaglutide is the most-faked peptide on the market, which makes its paperwork the most-faked too. Whether a vendor handed you a certificate of analysis or you're deciding whether to trust one before buying, this is what a real semaglutide COA contains, what each number means, and how to tell a tested vial from a decorated one.

The four things a real semaglutide COA shows

1. Identity against a reference standard. The lab runs your sample and a certified semaglutide reference standard on the same method, and the certificate states whether they match — retention time and UV character. Without a reference standard, “semaglutide” on the report is an assumption, not a result. Identity is the line that catches the worst case: a vial of something else entirely.
2. Chromatographic purity (area %). Of the peptide-related material in the vial, the percentage that is actually semaglutide rather than related impurities or degradation products. Good material typically reads high-90s.
3. Net-peptide content — the mg actually in the vial. The number fake-friendly COAs omit. Purity and content are different measurements: a “5 mg” vial can be 99% pure and hold 3 mg. If the certificate doesn't state measured mg per vial, the label claim was never checked.
4. A way to verify the certificate itself. A PDF can be edited in five minutes, and real COAs get reused for batches they were never run on. A serious lab gives every certificate a unique ID and a cryptographic fingerprint anyone can check — ours verify publicly at kmdanalytical.com/verify, no login, no trust required.

Semaglutide-specific things to look for

• The method should fit the molecule. Semaglutide is a lipidated peptide — it carries a C18 fatty-diacid chain — and it behaves differently on column than small water-loving peptides. A lab that publishes its method (RP-HPLC, column, gradient, detection wavelength) is showing its work; a certificate with no method section is asking for faith.
• Watch the units. Research vials are labeled in mg; a COA quoting only percentages, or content in units that don't match the label, deserves a second look.
• The vial on the certificate should be YOUR vial. Chain of custody is what separates “we tested this batch once, somewhere” from “we tested the vial in this photo.” Our certificates print the intake photo of the exact vial submitted.
• Blends aren't semaglutide COAs. Cagri/sema blends and similar products need each active identified and quantified separately — one “purity” number for a two-peptide vial is meaningless.

Red flags that end the conversation

• The same COA PDF appears on multiple vendors' sites for different lots.
• Purity to four decimal places, but no mg-per-vial content anywhere.
• No lab name you can call, or a lab that turns out to be the vendor.
• A “lot number” on the COA that doesn't match the vial label.
• No way to verify the certificate — no ID, no fingerprint, no lookup.

The certain way: test your own vial

Every check above interrogates someone else's paperwork. The stronger move — especially before relying on a larger batch — is sending one sealed vial for independent testing: identity against our certified reference standard, purity, and measured mg per vial, on a certificate you can read and anyone can verify. It's $150 for a single vial, typically 5–7 business days from receipt (7 business days maximum), and the process is exactly as described here.

Test my semaglutide →