FDA Puts BPC 157, TB 500, and 5 Other Peptides Under the Microscope: What Prescribers Need to Know About the 503A Review Lengea FDA Peptide Update: Category 2 Removals Explained 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 Which non FDA (United States Food and Drug Administration) approved peptides, such as BPC 157 (Body Protection Compound 157) and TB 500 (Thymosin Beta 500), are likely legitimate for medical use under strict supervision?