Collagen Supplementation: Evidence and Skepticism for Skin and Lifting

The source provides a comprehensive overview of the available evidence concerning collagen supplementation, particularly its effects on skin outcomes and lifting-related results. It notes that while some studies, especially industry-funded or low-quality research, show benefits for skin hydration and elasticity, high-quality studies often yield non-significant results, leading to skepticism about cosmetic efficacy. For physical performance, recent meta-analyses indicate that collagen supplementation combined with training may improve fat-free mass and maximal strength compared to non-protein placebos; however, the author questions the practical applicability of these findings since collagen is a low-quality protein compared to other viable sources. Ultimately, the author maintains a pessimistic view due to the messy evidence, methodological biases, and the lack of studies comparing collagen to more effective protein alternatives like whey or simple amino acids such as glycine.