The effect of oral supplements containing collagen peptides rich in X-Hyp or X-Hyp-Gly compared with normal collagen hydrolysates on skin elasticity and collagen holes: a randomised double-blind clinical study

Collagen peptides enriched with X-Hyp or X-Hyp-Gly have demonstrated resistance to digestive and systemic enzymes, suggesting their potential for improved absorption efficiency and enhancement of skin properties. This study aimed to evaluate the effects of oral supplementation with collagen peptides rich in X-Hyp or X-Hyp-Gly on skin properties in a clinical setting. A double-blind, randomized study was conducted on 30 healthy adult participants aged between 22 and 30. Normal collagen hydrolysates were used as the control, and each participant received a daily powdered drink containing either 5 grams of collagen peptides or hydrolysates (n = 15 in each group) for a period of 42 days. Skin elasticity was evaluated using the Cutometer, revealing a significant increase in the intervention group's skin elasticity (R2 values: 0.86 to 0.92, P < 0.001; R7 values: 0.77 to 0.84, P < 0.001). Collagen synthesis in the dermis was assessed using the SIAscope, demonstrating a substantial increase of 30.67 in the intervention group, while the control group exhibited a marginal increase of 0.49. In vitro digestion and cellular transport models were employed to evaluate the absorption and transport of Hyp-containing collagen peptides. LC-MS analysis demonstrated a significantly higher proportion of small peptide oligomers below 500 Da in the CP product compared to the control group (approximately 70% vs. 50%) after digestion. Additionally, the CP product exhibited a greater uptake of peptides (27%) compared to the control group (21%). These findings highlight the potential use of Hyp-containing collagen peptides with a low molecular weight in food supplements for improving skin health.