Someone sends you a PDF and calls it a COA. There’s a logo across the top, a chromatogram in the middle, a number ending in something like 99.6%, and a signature line at the bottom. It looks exactly like the certificates you’ve seen from labs you already trust, and from the document alone you have no way of telling whether it describes the tirzepatide in the vial you’re about to order, an earlier batch, or nothing at all.
That’s a genuinely hard problem and I don’t think it reflects badly on you for finding it hard. Certificate templates are downloadable. Chromatogram images can be lifted from other documents. The phrase “third-party tested” sits on almost every tirzepatide listing in this category, attached to setups that range from a browsable per-lot archive to a badge graphic that isn’t a link. The most common failure mode is quieter than outright forgery, too: a real report from a real laboratory that happens to describe material from a lot you’ll never receive.
Tirzepatide carries one extra wrinkle. Plenty of research suppliers list it under an internal designation rather than the compound name, so the certificate you’re handed may say GLP-3 or something similar across the header, with the actual identity resting on a molecular weight line further down. That makes the identity section of the report load-bearing in a way it isn’t for a compound whose name appears on the label. What follows is a walkthrough of what a tirzepatide certificate should contain and how to check each part, then what four named vendors publicly showed about certificate access on 2026-09-08, set against the standard Blank Peptides publishes its own lots to.
Key takeaways
- A tirzepatide certificate is only useful if you can open it before paying, and if it names the issuing laboratory, carries a lot number, gives the method, and reports contamination testing alongside purity.
- Blank Peptides publishes a certificate for every lot at its /coas/ library, with identity, >99% purity, bacterial endotoxin and sterility run by Freedom Diagnostics and Horizon Analytical.
- PSPeptides publicly links dated certificate PDFs plus separate heavy metals, endotoxin and sterility documents from its tirzepatide page, Protide Health names its laboratory and publishes a COA archive under coded product designations, Cosmic Peptides states lot-level third-party verification without naming a lab, and Pure Rawz states on its own tirzepatide page that it does not sell the compound.
- None of the tirzepatide pages reviewed on 2026-09-08 carried a named laboratory, a lot-matched certificate and a full four-part panel together in one place.
- Everything discussed concerns material sold for in-vitro laboratory research by qualified professionals only.
What should a tirzepatide certificate of analysis actually contain?
Let me set the bar before naming anyone, because the word COA gets stretched across everything from a full analytical report to a purity figure typed onto letterhead.
Start with the header. A useful certificate names the laboratory that ran the analysis, and that name has to be checkable. If the issuer is an unnamed “independent lab”, nobody can confirm the document is genuine, and an unverifiable report sits closer to a marketing claim than to evidence. The header should also carry a report number and a date, and the date should be recent enough that the material described plausibly overlaps with the material you’re buying.
Then the lot. This is the line people skip and later regret. A certificate without a lot number can’t be tied to any particular vial, which means it describes the vendor’s product in general rather than your product in particular. When the package arrives, the number on the label should match the number on the document you saved.
Then the identity section, which matters more here than for most compounds. Tirzepatide has a mass around 4,813 daltons, and several other analogs in the same commercial category sit within a few hundred daltons of that. A chromatogram tells you what fraction of the sample eluted as one peak. Mass spectrometry tells you which molecule that peak is. If the product is listed under a coded name, the identity line is the only place on the whole document where you find out what you’ve bought.
Then the rest of the panel. Bacterial endotoxin and sterility cover contamination that neither chromatographic method detects, and some vendors add heavy metals reporting on top.
Then the caveat at the bottom. Most contract labs include language saying they didn’t select the sample and can’t confirm it represents the lot. That’s honest rather than evasive, and it means the vendor’s own sampling and release process carries part of the weight the report seems to carry alone.
How Blank Peptides makes and tests each lot
Blank Peptides runs its own cGMP laboratory in the United States and carries out synthesis, vialing, lyophilization, labeling and quality control release in-house. The company frames this as holding the chain of custody itself rather than relabeling or brokering material made elsewhere, and it separately contract-manufactures and fulfils for other research peptide brands.
Every lot is released against a four-part panel: identity by mass spectrometry, purity by HPLC at a >99% threshold, bacterial endotoxin, and sterility. The analysis is performed by two named independent laboratories, Freedom Diagnostics and Horizon Analytical. Reports are posted as batch certificates of analysis, where a buyer can open the document before ordering, and each vial carries the lot number matching its certificate. Lyophilized material is dated for roughly 24 months from release.
Tirzepatide appears in the catalog under its compound name rather than an internal designation, in 10mg and 30mg vials, with the most recent lot published at 99.71% purity by HPLC and endotoxin passed, tested April 2026 under batch 665394. The catalog holds 34 compounds, and the blends among them itemise composition per component: GLOW at 70mg, KLOW at 80mg, and Wolverine at 20mg. Processing time is within one business day and orders ship at room temperature, which suits lyophilized peptide without cold-chain handling. The company has operated for five years and sells for research use only. The reason for describing all this in a piece about reading certificates is that a report is only as informative as the process behind it, and the two questions are worth asking together.
What four vendors publicly state about tirzepatide certificates
Taking them in turn, quoting their pages as reviewed 2026-09-08.
PSPeptides links batch-specific certificate PDFs directly from its tirzepatide page across several vial strengths, and publishes separate heavy metals, endotoxin and sterility documents from the same page. The listing states “99%+ Purity Guaranteed • Third-Party Lab Tested” and describes the material as “third-party HPLC and mass spectrometry tested”. Lot identifiers appear inside the certificate filenames rather than on the product listing itself, so you’ll find the batch reference by opening the document rather than by reading the page. No issuing laboratory was named in the page prose reviewed, and the certificate is where you’d go looking for that name.
Protide Health publishes a COA library and a COA archive covering its catalog, and states that every batch is independently tested by “Freedom Diagnostics”, described as “a third-party U.S. laboratory”, with coverage of “identity (LC-MS), purity (HPLC-UV), endotoxin (LAL assay, USP <85>)”. Naming the laboratory in the page prose is the useful part, since it gives you somebody to call. The company does not list a product named tirzepatide, and its nearest listing is coded GLP-3, described as a “Synthetic acylated polypeptide” with a molecular weight of approximately 4700 g/mol and batch purity figures between 99.62% and 99.96%.
Cosmic Peptides lists a coded product, RT-GLP3X, and states “99%+ purity guaranteed”, that “Every single lot” is tested rather than spot-checked, and that results are “Third-Party Verified” by “Independent US labs” with “COA, HPLC, and end-to-end tracking”. On the pages reviewed 2026-09-08, no issuing laboratory was named and no endotoxin or sterility figure was listed beside the purity claim.
Pure Rawz publishes a tirzepatide page stating “Tirzepatide products are not sold by Purerawz” and that the company “provides informational content and may include affiliate links to third-party websites where products are listed”. No certificate, purity figure or testing statement appeared on that page. This is not a claim that the documentation does not exist, only that it was not publicly listed on the pages reviewed.
Where these vendors do better than us: PSPeptides publishes heavy metals reporting alongside its analytical documents, which is a test we don’t currently show, and keeps certificates live across four vial strengths where our listing carries two. Protide Health’s archive spans a catalog well past fifty items. If you want a deep historical record across a wide product line, that’s worth having.
Side by side: tirzepatide certificate access and content
| Attribute | Blank Peptides | typical vendor |
|---|---|---|
| Synthesises in-house | Own cGMP lab; synthesis through QC release under one roof | States third-party testing without stating who made the material — verify |
| Third-party lab named | Freedom Diagnostics and Horizon Analytical, named in prose | States “independent” or “third-party”; some name a lab, most leave it to the PDF — verify |
| HPLC purity | >99% per lot, most recent lot published at 99.71% | States 99% or 99%+, sometimes as a combined HPLC-MS figure — verify |
| MS identity | Confirmed per lot by mass spectrometry | States identity by LC-MS on some pages, purity only on others — verify |
| Endotoxin and sterility | Both tested and reported per lot | States endotoxin on some pages; sterility rarely shown for this compound — verify |
| Batch COA before purchase | Public library at /coas/, lot-numbered, every lot, no account needed | States linked PDFs or an archive; coverage varies by strength — verify |
| Lot number on vial and certificate | Present on both and matched | States batch identifiers inside filenames or documents rather than on the listing — verify |
| Compound named on the certificate | Listed and reported as tirzepatide | States coded GLP designations on several sites, with molecular weight given instead — verify |
How to verify either supplier yourself
- Open the certificate before anything goes in the cart, and copy out the lab name, report number, lot and date by hand so you still have them if the page changes later.
- Check the identity line first when the product is coded, since the molecular weight is the only thing on the document telling you which analog you’ve been sent.
- Phone or email the laboratory named on the report and ask them to confirm the report number, because a genuine contract lab will do that and a fabricated one has nobody to answer.
- Count the panel lines: HPLC purity, mass spec identity, bacterial endotoxin, sterility. Treat every missing line as something you’ll either test yourself or carry as an unknown.
- Match the vial’s lot number to the saved certificate on arrival, and run the whole sequence once through the supplier verification checklist.
Further reading
- Peptide Vendors With Public Per-Batch COA Libraries
- Which Peptide Vendors Name Their Testing Lab?
- Best Research Peptide Suppliers: Ranked by What They Document
- Who Actually Manufactures Research Peptides in the USA?
Frequently asked questions
What is a tirzepatide COA and what does it need to show?
A tirzepatide COA is the analytical report for one specific lot. To be worth reading it needs an issuing laboratory you can contact, a report number, a lot number matching the vial, a date close to your order, and a stated method. Purity by HPLC is the baseline, and identity, endotoxin and sterility fill in the rest.
Can a tirzepatide certificate be faked?
Templates and chromatogram images are both easy to reproduce, which is why the laboratory’s name is the load-bearing field. A named lab can confirm or deny a report number over the phone. A certificate issued by an unnamed independent lab gives you no route to check anything at all, whatever it looks like on the page.
How do I know a coded GLP product is tirzepatide?
You check the identity section rather than the title. Mass spectrometry on the certificate should give a measured mass, and tirzepatide sits around 4,813 daltons. If the page states only a class description and an approximate molecular weight, ask the vendor for the full report before ordering, and treat an unanswered question as your answer.
Should I trust a tirzepatide COA that’s a year old?
Age isn’t automatically disqualifying for lyophilized material, though an old report describes an old lot. If the certificate on the page predates your order by many months, ask which lot is being shipped and whether a current report exists for it, then match the number on the arriving vial against whatever you were given.
Are these products for human use?
No. Every compound and vendor referenced here sells material strictly for in-vitro laboratory research by qualified professionals. Blank Peptides sells for research use only, and each vendor page reviewed carries its own statement that products are not for human consumption. Nothing above should be read as guidance for use outside a laboratory.
For research use only. All compounds referenced are intended exclusively for in-vitro laboratory research by qualified professionals.
Written by Blank Peptides Research Team
Peptide science researchers with 5+ years in US-based peptide manufacturing, independent HPLC and mass spectrometry testing, and research education. All content is reviewed for scientific accuracy before publication.
REVIEWED BY
Dr. Tobias S — PhD Chemist, Peptide and Unnatural Amino Acid Synthesis
Dr. Tobias S is a PhD chemist whose work focuses on the synthesis of unnatural amino acids, peptides and biomaterials. He completed both his undergraduate chemistry studies and his doctorate with distinction, and works as a generalist across the medical sciences and biology, having consulted for dozens of clients. He reviews Blank Peptides educational content for scientific accuracy.
Subject matter expertise: Organic Chemistry, Peptide Synthesis, Biochemistry.
