营销话术证据 B · meta 分析
口服玻尿酸 / 胶原嫩肤
真相
口服的玻尿酸在消化道里就被分解了；对皮肤起作用靠局部（注射或外用），不靠肠道吸收。
机制速览
胶原是把身体撑起来的脚手架：皮肤、骨、软骨、肌腱、韧带、血管壁、巩膜里的结构，大多是它搭出来的。它也是身体里含量最高的蛋白质，约占总蛋白的 25-30%。
来源（1）
- Khatri, M., Naughton, R. J., Clifford, T., Harper, L. D., & Corr, L. (2021). The effects of collagen peptide supplementation on body composition, collagen synthesis, and recovery from joint injury and exercise: a systematic review. Amino Acids, 53(10), 1493-1506. Systematic review of 15 RCTs (from 856 articles screened) combining collagen peptides with exercise: 12 in recreational athletes, 2 in elderly participants, 1 in untrained pre-menopausal women. Outcomes: joint pain and recovery from joint injury, body composition, muscle soreness and recovery, muscle protein and collagen synthesis; no skin endpoint, and the abstract reports no pooled effect estimate. Collagen synthesis rates were elevated with 15 g/day, with no significant effect on muscle protein synthesis vs isonitrogenous higher-quality protein (abstract, PMID 34491424; full text, PMC8521576).