Tirzepatide is FDA-approved only as Eli Lilly's Mounjaro and Zepbound; research-labeled tirzepatide is a different, unapproved product that FDA has warned sellers about. Six of the eight vendors we rate list it; on October 7, 2026, PSPeptides posted the most complete lot-matched testing, and American Peptides, our #1 overall pick, had lot-matched COAs for every size but named no lab.
Notice: Research peptides are sold for in-vitro laboratory research only. They are not FDA-approved, not for human or animal consumption, and this page is not medical advice.
This page covers prices and certificates only, with no dosing, protocol or human-use content, per our policy. Our criterion: a tirzepatide certificate that names the lab and the lot beats a "third-party tested" badge. We don't test products; we check what each vendor publishes.
What tirzepatide is, and how research vials differ
Tirzepatide is a peptide that activates the GLP-1 and GIP receptors, per FDA's Zepbound announcement. Lilly sells it as Mounjaro, approved May 13, 2022, and Zepbound, approved November 8, 2023. Approved uses and trial data are covered in semaglutide vs tirzepatide.
A research-labeled vial is not Mounjaro or Zepbound. It isn't made under Lilly's approval, wasn't studied in Lilly's trials and isn't reviewed by FDA for quality. Nothing on this page is about the prescription products.
Regulatory section: shortage, compounding and "research" labels
- Shortage over. FDA determined the tirzepatide injection shortage was resolved on December 19, 2024. It didn't intend to act against outsourcing facilities until March 19, 2025, and says the enforcement-discretion period for state-licensed pharmacies "has ended" (FDA, content current as of April 1, 2026).
- 2026 compounding moves. On February 6, 2026, FDA said it would restrict GLP-1 ingredients used in mass-marketed non-approved compounded drugs. On April 30, 2026, it proposed excluding semaglutide, tirzepatide and liraglutide from the 503B bulks list (Pharmacy Times).
- "Research" labels. FDA's GLP-1 page (current as of October 1, 2026) says it has warned companies selling tirzepatide and other GLP-1-class drugs "falsely labeled 'for research purposes' or 'not for human consumption'" (FDA).
- Warning letters. FDA's September 2025 letter to GenLabMeds cites tirzepatide products. The August 24, 2026 Peptide Partners letter listed "GLP-2 T (Tirzepatide)" as an unapproved new drug despite "for research use only" labels.
More: FDA peptide regulation in 2026 and our regulatory news log.
Tirzepatide by vendor
Prices checked October 7, 2026, including any displayed sale price. $/mg is price divided by labeled mg. "With our code" is arithmetic, not a checkout quote; we couldn't confirm whether codes stack with sale prices. Vendors appear in our editors' order.
| Vendor | Listed as | Price (size) | $/mg | With our code | Tirzepatide COA evidence |
|---|
| American Peptides | TIRZ-GLP2 | $100 (10 mg); $85 Subscribe & Save | $10.00 / $8.50 | No code | Lot-matched PDFs for 10-100 mg (e.g. lot TIR10-0803); no lab named |
| NextGenPeps | GLP-TZ | $126, was $158 (10 mg); out of stock | $12.60 | No code | Bioviridian, Sep 25, 2026, 99.76%; no lot shown |
| PSPeptides | Tirzepatide | $54.99 (10 mg) to $199.99 (60 mg) | $5.50 to $3.33 | $49.49 for 10 mg with CHECKED ($4.95/mg) | North American Diagnostics, batch PSP-08202026TZ, Aug 2026, 99.97%, plus safety panel |
| Ascension Peptides | T-10, T-30 | $90, was $124.99 (10 mg); $180, was $249.99 (30 mg) | $9.00 / $6.00 | $45 for T-10 with AFFILIATE50OFF, first order ($4.50/mg) | Kovera Labs, batch 35-05260628, May 26, 2026 (30 mg) |
| Licensed Peptides | LP2-T | Login required | - | Affiliate5 (5% off) | Report images by lot, e.g. V260423-7 (10 mg) |
| Alpha Pro Peptides | GLP-2 | $55.99 (10 mg); $64.99 (30 mg) | $5.60 / $2.17 | No code | Lot AP-T10-0426, May 18, 2026, 99.85%; lab not named on testing page |
PSPeptides' full ladder: 10 mg $54.99, 15 mg $64.99, 20 mg $79.99 (out of stock), 30 mg $114.99, 40 mg $144.99, 50 mg $174.99, 60 mg $199.99. With CHECKED, the 60 mg works out to $179.99 ($3.00/mg), the same per-mg figure as Ascension's T-30 with a first-order code ($90).
Peptide Plugs and Swiss Chems had no tirzepatide listing on October 7, 2026; Swiss Chems' store search returned zero results.
Notes on each vendor's documentation
- American Peptides: the product page names tirzepatide in its title and lists 10, 20, 30, 60 and 100 mg, but only the 10 mg price. Its COA page has current and superseded lots for each size, with no lab, date or purity shown. The page lists both "99.9% Purity" and "≥99%." Review
- NextGenPeps: the GLP-TZ page calls it a dual GLP-1/GIP agonist "conceptually aligned with ... tirzepatide" without saying it is tirzepatide. Its COA library has a September 2026 Bioviridian report and a December 2025 Bioregen one. No lot numbers. Review
- PSPeptides: the product page links a certificate plus endotoxin, sterility, heavy metals and fentanyl reports for each size. The 10 mg certificate reports 99.97% purity and 9.76 mg measured. The page also lists reconstitution volumes and points to a separate dosage guide, which we count against PSPeptides. Review
- Ascension Peptides: the T-10 page describes a 39-amino-acid GIP/GLP-1 dual agonist but doesn't name it; its certificate file names say "Tirzepatide." The June 2026 Kovera entry had no download link, so the newest linked T-10 report is a February 2026 MZ Biolabs one. T-30 links a May 2026 Kovera report. Review
- Licensed Peptides: its purity reports page lists LP2-T from 5 to 60 mg; some file names say "GLP-2-T." Lot V260123-1 appears on three LP2-T sizes and, per our review, also on a 5-Amino-1MQ report. Prices need a free account (research access). Review
- Alpha Pro Peptides: its store lists GLP-2 at 10, 30, 40 and 60 mg (60 mg out of stock) under a site-wide "Buy 1 Get 1 Free" banner. The 30 mg price looks low next to the 10 mg, so confirm it in the cart. Its testing page shows May 2026 lots for all four sizes (10 mg: certificate, 10.75 mg measured). Review
Why code names are a labeling concern
TIRZ-GLP2, GLP-TZ, T-10, LP2-T and GLP-2 are all sold without "tirzepatide" as the product name. FDA identified "GLP-2 T" by name in the Peptide Partners letter, so a code doesn't change the legal analysis. It does make certificates harder to match to vials. Our method counts code names against a vendor.
How to check a tirzepatide COA
- Match the lot to the size. American Peptides, PSPeptides and Alpha Pro post one per size.
- Check identity by mass spectrometry, not just HPLC purity, especially when the product name is a code.
- Compare measured mg with the label before any concentration math.
See how to read a peptide COA, peptide purity vs net content and the COA checklist.
Independent test data
Finnrick's tirzepatide page lists 262 vendors and 2,744 tests. None of our eight vendors appeared in its public rows on October 7, 2026; ranks 9-20 require an account. Every certificate above was commissioned by the vendor. More: what is Finnrick?
Codes and vendor links
We have affiliate relationships with PSPeptides (CHECKED, 10% off), Ascension Peptides (AFFILIATE50OFF, 50% off a first order) and Licensed Peptides (Affiliate5, 5% off), and may earn a commission. See peptide coupon codes. In our editors' order:
Bottom line
PSPeptides pairs the deepest tirzepatide testing with low per-mg prices, though its dosing-related content is a labeling problem. American Peptides, our #1 overall pick, has lot-matched certificates for every size without naming the lab. Ascension's first-order code matches PSPeptides' lowest per-mg price on its 30 mg vial, if it applies to sale prices. None of these vials is Mounjaro or Zepbound. Related: retatrutide vendors, our homepage shelf and the best peptide vendors in the USA.
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