Abstract
Collagen dietary supplements are becoming increasingly popular as a means to reduce signs of skin ageing. The objective of this three-way, randomised, placebo-controlled, double-blind study was to examine and contrast the effects of dietary supplementation with a daily dose of 5 g hydrolysed collagen with 80 mg of vitamin C (CP product) and their combination with 30 mg of hyaluronic acid (CPHA product) over 16 weeks. Validated methods were utilised for the objective evaluation of skin parameters. In total, 87 subjects (women, 40-65 years) completed the entire trial, distributed across the groups as follows: placebo group (n = 29), CPHA group (n = 28), and CP group (n = 30). The results showed beneficial effects of both test products, with notable enhancements in dermis density, skin texture, and a reduction in the severity of wrinkles. In contrast, the administration of either of the products did not yield any significant impacts on skin elasticity or hydration. Observation of the investigated skin parameters did not show superior effects of the addition of hyaluronic acid (HA) to collagen. Therefore, the ability of supplementation with HA to improve the effects on investigated skin parameters beyond the supplementation of collagen alone cannot be confirmed.