FDA Warning Letters to Peptide Sellers

An official notice that FDA considers a company to be violating federal law — for peptide sellers, usually selling unapproved new drugs or misbranded products. It is not a criminal charge, and companies can respond and correct the issues.

In the letters listed here, the most frequently named compounds are Retatrutide (21), Semaglutide (19), Tirzepatide (9), SS-31 (4), PT-141 (2), Cagrilintide (2), Survodutide (1), Mazdutide (1).

We searched FDA's warning-letter database for peptide terms (peptide, semaglutide, tirzepatide, retatrutide, BPC-157 and others) and kept letters dated 2023 or later whose text concerns peptide products. Checked October 19, 2026.

No. FDA issues letters to a small share of sellers, and this list only covers letters FDA has posted. Absence from the list is not evidence of compliance.