How to read a Merit certificate of analysis

The question sales hears most from a clinic or research buyer isn't about price. It's “is this real” — proof of purity and identity, not a number on a product page. Merit tests every lot through an independent laboratory and publishes the certificate before the lot ships. This walks through one certificate, line by line, using an actual Merit lot as the example.

The lab, named

Every Merit certificate of analysis is issued by ILS Laboratories, an ISO/IEC 17025 accredited testing laboratory in San Diego, California. The accreditation and the lab's address are printed on the certificate itself, and every certificate carries a verification link and access code that resolves on the lab's own domain, not ours. That is the specific, checkable fact behind “third-party tested”: a named lab, an accreditation standard, and a document you can verify without asking us. Much of the category cites an unnamed or offshore lab, or no lab at all.

One lot, read line by line

The example below is a real Merit certificate for a 10mg tirzepatide lot (LOT2026-06-0001, COA-2026-8L06KX, issued 7/30/2026). Every current lot has its own certificate at meritsciences.com/coa — the numbers below describe this one lot, not a standing spec.

Header: what lot this is

The top of the certificate identifies the material and ties the document to one physical batch: compound and labeled content (“Tirzepatide - 10mg”), lot number, a unique COA number, the date the sample was received and the date it was tested, the sample's physical appearance, and the client of record. If any of these don't match the vial in front of you, the certificate isn't for that vial.

Identity: is it the molecule on the label

Identity is reported separately from purity because they answer different questions. This certificate confirms identity by HPLC retention-time matching: the sample is run against a reference standard for the named compound under the same chromatographic conditions, and its retention time is compared. A match confirms the sample behaves like the reference compound; a mismatch fails the lot outright, regardless of how clean the purity trace looks.

Purity: how much of the vial is the target peptide

Peptide purity is measured by RP-HPLC with area normalization at 214nm — the main peak's area as a percentage of all peptide-related peaks, excluding non-peptide process impurities. This lot reported 99.41% against a specification of 95.0% or higher. That's an area ratio, not a mass measurement, which is exactly why the certificate also reports net peptide content separately: for this lot, 10.57mg of actual peptide, reported rather than pass/failed against a spec, because label claim and analytical net content are two different figures by design.

What else gets tested

Beyond identity and purity, this certificate's full QC panel covers:

• Heavy metals (ICP-MS) — arsenic, cadmium, lead, mercury and chromium, each against its own limit. This lot: not detected on four of five, chromium at 0.377 ppm against a 10 ppm limit.
• Sterility (PCR) — screens for microbial growth. This lot: no growth detected.
• Endotoxin (USP <85>) — bacterial endotoxin, reported as a quantitative EU/mL value rather than pass/fail, since no single universal threshold applies across research-use matrices. This lot: 0.084 EU/mL.
• Fentanyl screen — an immunoassay contamination check. This lot: not detected.

The sign-off

The certificate closes with a named lab director's signature and issue date, plus the COA number, access code and a verify link to the lab's own portal. That link is how a buyer confirms the document in front of them was actually issued by the lab, not edited after the fact.

What this page is not

This is a reading guide for one document type, not a claim about what any compound does. It reports identity, purity and contamination-screening results only. It says nothing about dosing, protocols, or outcomes, and none of it is guidance on preparing or administering any compound.

Frequently asked

Does ISO/IEC 17025 accreditation mean a product is FDA-approved?

No. ISO/IEC 17025 is an accreditation of a testing laboratory's competence and quality system, audited by an accreditation body. It says the lab that ran the test is qualified to run it. It says nothing about a compound's regulatory status, and no compound discussed here is FDA-approved.

Why does identity get tested separately from purity?

Purity measures what fraction of the detected material is the main peak; it says nothing about which molecule that peak is. A vial could return a clean purity result and still be the wrong compound. Identity testing, run separately, is what confirms the material matches the compound named on the label.

Where do I find the certificate for the lot I actually have?

Every current lot's certificate is linked from its product page and archived at meritsciences.com/coa, searchable by lot number.

For research use only. Not for human or veterinary use. Not FDA-approved. This article explains how to read a certificate of analysis; it is not medical, dosing or regulatory guidance, and the lot referenced is shown for illustration — always check the certificate for your own lot.