Siim Land analyzed human clinical trials for 15 popular peptides used for longevity, recovery, and health optimization. While peptides like BPC-157 and TB-4 are widely used for joint healing, they lack human studies. Thymosin alpha-1 scored highest with extensive clinical evidence for immune support and approval in 35 countries. Growth hormone secretagogues like MK-677 and CJC-1295 showed proven effects on muscle mass and sleep quality. Epitalon demonstrated promising circadian rhythm benefits but research comes mainly from its Russian discoverer. Retatrutide emerged as the most impactful for overall health through dramatic weight loss. Most peptides had good safety profiles but limited human evidence for their popular uses.
