Oral hyaluronan relieves wrinkles: a double-blinded, placebo-controlled study over a 12-week period

BACKGROUND Hyaluronan (HA) has critical moisturizing property and high water retention capacity especially for human skin. This study aimed to evaluate the effect of oral intake of HA. METHODS The mean molecular weight (MW) of HA is 2 k and 300 k. Sixty Japanese male and female subjects aged 22-59 years who presented with crow's feet wrinkles were randomly assigned to the HA 2 k or HA 300 k at 120 mg/day or the placebo group. The subjects were administered HA at a rate of 120 mg/day or a placebo for 12 weeks. The skin wrinkles were evaluated by image analysis of skin wrinkle replicas, and their skin condition was evaluated using a questionnaire survey. RESULTS During the study period, the HA groups showed better level of the whole sulcus volume ratio, wrinkle area ratio, and wrinkle volume ratio than the placebo group. After 8 weeks of ingestion, the HA 300 k group showed significantly diminished wrinkles compared with the placebo group. Skin luster and suppleness significantly improved after 12 weeks in all groups compared with the baseline. CONCLUSION The results suggest that oral HA (both HA 2 k and HA 300 k) inhibits skin wrinkles and improves skin condition.