Objective　To investigate the safety and efficacy of hyaluronic acid for improving skin condition, a placebo-controlled double-blind comparative study was conducted in women who were concerned about wrinkles and dryness.
Methods　Twenty-eight women were allocated to one of 2 groups receiving either a hyaluronic acid-containing diet or a placebo diet 3 times daily for 8 weeks. The daily intake of hyaluronic acid was 240 mg. The efficacy endpoints included skin moisture content, skin elasticity, and wrinkle characteristics based on skin replica analysis at baseline（before intake）, and 4 and 8 weeks of intake. The safety endpoints included physiological, hematological, and blood biochemical adverse events.
Results　The hyaluronic acid group（compared to the placebo group）showed a tendency toward improved skin moisture, had significantly improved skin elasticity at 8 weeks of intake compared with baseline, and had significantly improved mean maximum wrinkle depth at the corner of the right eye at 4 weeks of intake. Mean wrinkle area ratio and maximum wrinkle area ratio at the corner of the left eye were significantly increased at 4 and 8 weeks of intake compared with baseline in the placebo group, but not in the hyaluronic acid group. No adverse events related to food intake were observed, suggesting that intake of hyaluronic acid is safe.
Conclusion　The results suggest the efficacy of a diet containing hyaluronic acid for improving skin moisture, elasticity, and wrinkles.