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 BPC 157: Miracle Healing Peptide or Hidden Danger? Everyone online is suddenly injecting peptides. But almost nobody understands the scienceor the regulation. The FDA recently shifted several peptides off the Category 2 safety risk list tied to compounding rules. First, that Is BPC 157 Legal? Understanding Its Status and Implications