Low-Molecular-Weight Collagen Peptide Supplementation Improves Cellulite Severity, Skin Elasticity, and Hair Shaft Diameter: A Clinical Study with Pharmacokinetic Evaluation

The objective of this study was to evaluate the potential applications of low-molecular-weight collagen peptides (LMWCPs), produced through enzymatic hydrolysis of fish skin-derived gelatin using a specific protease. LMWCP is enriched in Gly-X-Y tripeptide sequences, particularly Gly-Pro-Hyp (GPH). Preliminary human pharmacokinetic data showed that oral LMWCP markedly increased systemic exposure to GPH, yielding an approximately 54-fold higher area under the concentration-time curve from 0 to 2 h (3388 ± 1084 ng·h/mL) than general collagen. In a subsequent randomized, placebo-controlled trial, 114 women aged 20-50 years with thigh cellulite and self-reported hair thinning received either LMWCP (1000 mg/day) or placebo for 24 weeks. Efficacy endpoints included cellulite severity, dermal-subcutaneous border length, skin roughness, skin elasticity, and hair diameter. The LMWCP group demonstrated significant improvements in cellulite severity, dermal-subcutaneous border length, skin roughness, and skin elasticity at weeks 12 and 24 compared to the placebo group. Hair diameter also increased significantly at week 24, with a larger proportion of participants in the LMWCP group exhibiting measurable hair thickening. These findings indicate that LMWCP, characterized by high GPH content and enhanced systemic exposure resulting from targeted enzymatic hydrolysis, exerts beneficial effects on both skin and hair parameters. Daily intake of LMWCP for 24 weeks effectively reduces thigh cellulite and promotes hair thickness, supporting its potential as an orally administered functional ingredient for skin and hair health.