Peptides are often well tolerated, but they can still cause temporary reactions while the body adapts. Some commonly reported effects include: BPC 157 headaches, nausea, increased appetite TB 500 TB 500 vs BPC 157: Comprehensive comparison of healing peptides Peptides for Longevity: BPC 157, TB 500, GHK Cu & CJC 1295 BPC 157 And TB 500: Background, Indications, Efficacy, And Safety GlobalRPH Gray Market Peptides: So Much Hype, So Little Data