People are turning themselves into lab rats': the injectable peptides craze sweeping the US Well actually The Guardian Should peptides be allowed in natural bodybuilding? If it's natural, what does that actually mean? Many peptides aren't detectable in standard urine tests Some support recovery, healing, and overall health Yet Synthetic Peptides Banned! World Natural Bodybuilding Federation NFL and NFLPA inform players of addition to banned substance list: BPC 157, an experimental peptide not approved for use by humans that has been found in supplements and recovery treatments. BPC 157 for erectile dysfunction