Analysis: The peptide problem: Hype is outrunning the evidence McMaster News Deep Dive: Regulatory Status of Popular Compounded Peptides Holt Law 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's Overreach on Compounded Peptides FDA to weigh easing limits on unproven peptides promoted by RFK Jr.