Why RFK Jr. backs peptides but questions vaccines STAT Injectable peptides touted as new fountain of youth. But the science isn't there CBC Radio What's behind the trendy peptide injections being sold by influencers and RFK Jr. allies AP News In the era of Make America Healthy Again, the popularity of peptidesshort chains of amino acids that often act as signalling molecules in the bodyhas risen sharply. Many compounding pharmacies, which produce