Has anyone independently verified a Homopeptide tirzepatide batch COA?

What I have: Homopeptide · tirzepatide.

The claim is plausible, which is exactly why I want to check it.

I am able to read a paper if someone points me at one.

Is there data behind this, or is it received wisdom?

Answer first: vet the documentation before you vet the supplier, because documentation is the only thing you can assess before spending anything.

Independent submission costs a fraction of a mid-sized order at any of the services this community uses, and it converts an opinion into a number attached to your own material.

The pre-order sequence: request a lot-specific certificate for the exact line, check that it names a lot code rather than a batch family, check that it carries the column, gradient and detection wavelength, and check the analysis date is recent relative to the lot.

Testing narrows uncertainty. It does not turn research-grade material into something with release testing behind it.

Ask for the lot-specific certificate before ordering. It is free and it is decisive.

A certificate without a method section is a claim rather than a measurement, and that distinction does most of the work here.

Ask what happens if a result comes back outside specification. The answer is informative regardless of what it is, and the question itself tells you something about how it lands.

Repeat the exercise on a second lot months later. Lot-to-lot agreement is the property that actually predicts your next order, and it cannot be established from one submission.

The independent testing services this community references — Janoshik, Medutest, PeptideMeter and VendorInvestigate — publish results that can be searched by supplier, compound and date, which makes prior lots checkable.

Small first order, independent submission, then scale. In that order.

Worth being precise here: this is the most answerable question on the site, because every step is cheap and every step is checkable.

Published third-party data on a named lot is worth more than any aggregate rating, because it is about a specific object rather than about an average of other people's objects.

Aggregate community ratings, including the one on this site, are opinion averages rather than measurements and should carry less weight than a single result on your own lot.

Write your accept threshold down before the result arrives.

Answering this needs to know whether you have already ordered, because the pre-order checks and the post-arrival checks are different lists.

Set your accept threshold before you see the result. Deciding after the number arrives is how thresholds become negotiable, and everybody does it unless they wrote it down first.

Published inter-laboratory comparisons of peptide purity routinely find spreads of half a per cent to a per cent on identical material, which sets a realistic expectation for agreement.

Match the code on the glass to the code on the certificate. Everything else is secondary.