Evidence Level
Moderate
Collagen peptides have emerged as one of the most well-evidenced beauty and joint supplements. A 2019 meta-analysis of 11 RCTs confirmed benefits for skin hydration and elasticity. For joints, the Clark et al. (2008) study in athletes and multiple osteoarthritis trials show meaningful pain reduction. The Shaw et al. (2017) study on tendon collagen synthesis has changed sports medicine practice — many physiotherapists now recommend 15 g collagen + vitamin C before rehab exercises. Quality varies between products; look for hydrolyzed peptides (2-5 kDa molecular weight).