Key Takeaway
Meta-analysis of 23 RCTs found collagen supplements appeared to improve skin hydration and elasticity overall, but industry-funded and low-quality studies drove the positive results while independent high-quality studies showed no effect
Summary
This systematic review and meta-analysis of 23 RCTs (1,474 participants) examined collagen supplements for skin aging. Overall, collagen appeared to improve skin hydration, elasticity, and wrinkles. However, critically, subgroup analysis by funding source revealed that only industry-funded studies showed benefits, while independent studies showed no effect. Similarly, high-quality studies showed no significant effects while low-quality studies did.
Methods
Systematic review and meta-analysis. PubMed, Embase, and Cochrane Library searched through June 2024. Included 23 RCTs with 1,474 participants. Subgroup analyses by funding source and study quality. Published in The American Journal of Medicine.
Key Results
Overall meta-analysis: significant improvements in skin hydration, elasticity, and wrinkles. Subgroup by funding: industry-funded studies showed benefits; non-industry studies showed no effect. Subgroup by quality: low-quality studies showed benefits; high-quality studies showed no significant effect.
Limitations
Strong funding bias - results driven by industry-sponsored studies. Quality-dependent results undermine overall positive findings. Authors concluded there is currently no clinical evidence to support collagen supplements for preventing or treating skin aging.