Background: Topical as well as oral 'collagen' is widely popularized and claimed to possess anti-aging properties for the past several years. Few placebo-controlled trials exist.

Objectives: Primary: To evaluate the effect of collagen hydrolysate (CH) ingestion for 4 weeks on skin elasticity. Secondary: To compare the effects of CH ingestion on skin elasticity between sun-exposed and sun-protected areas.

Materials and methods: This study was a prospective, randomized, double-blind placebo-controlled trial comparing the effects of daily intake of 5-g oral CH and placebo in post-menopausal women. Participants were evaluated for skin elasticity, using cutometer at baseline, 2 and 4 weeks after randomization and 4 weeks after discontinuation of study agents.

Results: A total of 36 participants were enrolled. Skin elasticity measured from left and right cheeks in participants receiving CH increased compared to placebo (p=.006, .03, respectively). After 4 weeks of discontinuation of study agents (week 8), skin elasticity measured from both left and right cheeks remained different between CH and placebo group (p=.01, .004, respectively).

Conclusions: We demonstrated significant improvement of skin elasticity in sun-exposed areas after 4 weeks ingestion of marine CH. The improvement of elasticity remained 4 weeks after discontinuation of study agents. There were no severe adverse effects during the study.