Massive collagen review finds skin and joint benefits, but no athletic boost

The largest umbrella review of collagen research (nearly 8,000 participants across 113 randomized trials) finds collagen supplements can improve skin hydration and elasticity and reduce osteoarthritis pain with longer use; modest improvements in muscle and tendon structure; little evidence for enhanced athletic performance or recovery; mixed or inconclusive results for metabolic and dental health; overall, collagen may support healthy aging but is not a quick fix for sports performance, and more high-quality trials are needed.