BPC 157: Experimental Peptide Creates Risk for Athletes Some peptides are FDA approved drugs. Some are legal supplements. Some are neither. The same word, peptide, covers all three categories. The regulatory status of the specific compound is what determines legality. FDA Targets GLP 1 and Peptide Compounding, Advertising and 'Research Use Only' Labeling Gray Market Peptides: So Much Hype, So Little Data