This systematic review and meta-analysis evaluates the efficacy and safety of oral and topical peptides for improving hydration, elasticity, wrinkles, and luminosity in aging skin. 19 randomized controlled trials with 1341 participants were analyzed. The peptides significantly improved skin hydration and brightness with a modest wrinkle reduction effect (MD = 0.27, p = 0.04). Oral polypeptides had the greatest benefit (MD = 1.5, p = 0.01). Effects on skin elasticity and density were inconsistent. The peptides were well tolerated with minimal adverse effects. The authors recommend larger studies with standardized outcomes and histopathological evaluation. The registration identifier is CRD420250652779.