How different peptide therapies may affect your body Prenuvo blog Unauthorized injectable peptide drugs seized and sold by Canada Peptide may pose serious health risks Canada.ca Sources: U.S. Food and Drug Administration (FDA) Compounding and the FDA (503A & 503B guidance) FDA warning letters on unapproved peptide products National Institutes of Health (NIH) PubMed In 2026, the question "Are peptides legal?" has been answered with a decisive regulatory crackdown. , The FDA has moved beyond general oversight into targeted enforcement. Popular wellness FDA to weigh easing limits on unproven peptides promoted by RFK Jr. FDA Targets GLP 1 and Peptide Compounding, Advertising and 'Research Use Only' Labeling