Beauty, Hair & Collagen

The primer

This category is dominated by marketing, so calibrate expectations. Hydrolysed collagen peptides (also called collagen hydrolysate) have accumulated genuine RCT evidence — meta-analyses show modest improvements in skin elasticity, hydration, and joint comfort at 2.5–15 g per day over 8–12 weeks. Type I & III support skin, Type II supports cartilage. What actually happens: collagen is broken down into amino acids and small peptides that stimulate your body's own collagen production. Biotin (vitamin B7) is heavily marketed for hair and nails, but the evidence only supports benefit for people with an actual biotin deficiency (rare) — for everyone else, the gains are usually placebo. Notably, biotin can skew certain blood tests, so mention it before lab work. Other beauty-adjacent nutrients worth considering: vitamin C (essential cofactor for collagen synthesis), zinc, and marine omega-3s. None of these substitute for sunscreen, sleep and hydration — which remain the highest-leverage beauty interventions.