Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis
Human clinical trials demonstrate improvements in skin hydration, elasticity, and wrinkle appearance following collagen peptide supplementation.
This 2023 open-access paper in Nutrients synthesizes randomized controlled trials on whether oral collagen improves visible and measurable signs of skin aging. It focuses on hydrolyzed collagen supplements and quantifies effects on hydration, elasticity, and wrinkles in adults. (PubMed)
Key facts
Citation: Nutrients, 2023; 15(9):2080 (PMCID: PMC10180699) (PubMed)
Design: Systematic review + meta-analysis of RCTs
Trials / participants: 26 RCTs, 1721 participants (PMC)
Intervention: Oral hydrolyzed collagen (various sources, doses, 4–24 weeks) (PMC)
Main outcomes: Skin hydration, elasticity, wrinkles / roughness
Background and aim
Collagen is the main structural protein of the dermis; its degradation and disorganization are hallmarks of skin aging. Many supplements claim anti-aging benefits, but clinical evidence has been scattered. The authors aimed to comprehensively evaluate RCTs of oral collagen for skin anti-aging outcomes using PRISMA-guided methods and quantitative meta-analysis. (PMC)
Methods
The authors searched multiple databases up to early 2023 and included placebo-controlled RCTs of oral collagen in generally healthy adults that reported objective skin outcomes. Twenty-six trials (1721 participants) were pooled. Outcomes included corneometry (hydration), cutometer measurements (elasticity), and imaging or profilometry for wrinkles/roughness. Risk-of-bias was assessed with standard tools, and subgroup analyses examined collagen source, dose, and duration. (PMC)
Main findings
Meta-analysis showed that oral hydrolyzed collagen produced statistically significant improvements in:
Skin hydration vs placebo (overall effect Z ≈ 4.94, p < 0.00001) (PMC)
Skin elasticity vs placebo (overall effect Z ≈ 4.49, p < 0.00001) (PMC)
Wrinkle/roughness measures also tended to improve in many individual trials, though heterogeneity of instruments limited pooling. Subgroup analyses suggested hydration benefits may vary by collagen source and supplementation duration, but the authors did not find clear statistically significant differences between collagen types for elasticity. (PMC)
Limitations and interpretation
The review notes several concerns: many trials had small sample sizes, industry funding, variable dosing regimens, and short follow-up (often 8–12 weeks). Outcome measures and reporting were heterogeneous, and blinding methods were not always clearly described. (PMC)
Overall, the paper concludes that oral hydrolyzed collagen appears to modestly but significantly improve skin hydration and elasticity compared with placebo over weeks to a few months, while emphasizing the need for larger, independent, longer-term RCTs to confirm durability, optimal dosing, and clinical relevance of the observed changes. (PMC)