FDA warns five peptide vendors over SS-31 and other unapproved peptides
The FDA has posted five warning letters — all dated August 24, 2026, all issued by CDER's Office of Unapproved Drugs and Labeling Compliance — to online peptide vendors: Peak Performance Peptides, Royal Peptides LLC, NuScience Peptides LLC, Peptide Partners LLC, and TXP Innovations LLC (Tex Peptides). Four of the five were cited for selling SS-31 (elamipretide), and the letters for Royal Peptides and TXP specifically cite marketing claims about mitochondrial function. Because elamipretide is now FDA-approved as Forzinity for Barth syndrome, the agency has a clean “approved counterpart” enforcement hook. Each company got 15 business days to correct.
Who was warned and why?
Each letter followed a July 2026 review of the company's website. FDA identified specific peptides — GLP-1s, retatrutide, tesamorelin, PT-141, SS-31/elamipretide — cited labeling and marketing claims establishing the products' intended use as drugs under the FD&C Act, and concluded they are unapproved new drugs. No vial was tested; this is a marketing and labeling action start to finish.
Why does SS-31 matter here?
SS-31/elamipretide is the mitochondria-targeted peptide — now an approved medicine (Forzinity) for Barth syndrome. Vendors selling it online as a “research chemical” with body-function claims are, in FDA's framing, selling an unapproved version of an approved drug. That makes the enforcement unusually clean.
What does “research use only” actually protect?
Not this. Across the letters, FDA's position is that a disclaimer does not control a product's legal status: claims about what a compound does in the body, human dosing guidance, and testimonials on the seller's own website can establish human-use intent regardless of the label. Bacteriostatic water sold alongside peptides for reconstitution was treated the same way.
What should consumers take away?
Gray-market peptides are an evidence and safety lottery — and the FDA is now working through the supply chain segment by segment (telehealth marketers in March and June, compounding rules being tightened, direct-to-consumer vendors now). If a peptide has a real evidence base, it travels through trials and approvals, not a “research use only” checkout page.
Where the evidence stands
- Established: The five warning letters are official FDA enforcement records (dated Aug 24, posted Sept 1, 2026), analyzed by multiple law firms; vendor names and cited compounds are documented.
- Contested: Vendors may dispute FDA's interpretation of their marketing; 15-business-day responses were pending at last report.