Educational only. Not medical or legal advice. This site summarizes public U.S. government statements as of October 22, 2026. It does not sell, recommend or endorse any product, and it does not give dosing information. Talk to a licensed clinician about any medicine, and check the linked FDA pages for the latest version.
What is a peptide?
Key FDA factFor regulatory purposes, FDA considers any amino acid polymer of 40 or fewer amino acids to be a peptide, not a protein. [FDA CDER MAPP 5016.3] FDA regulations define a "protein" as an alpha amino acid polymer with a specific, defined sequence greater than 40 amino acids in size (21 CFR 600.3(h)(6)). [FDA CDER MAPP 5016.3]
Approved vs. unapproved
FDA-approved drugs go through FDA's premarket review for safety, effectiveness and quality. Compounded drugs are not FDA-approved. [FDA] Unapproved versions of GLP-1 drugs such as semaglutide and tirzepatide do not undergo FDA's review for safety, effectiveness and quality before they are marketed. [FDA]