Oral Collagen Shown to Enhance Skin Hydration and Elasticity, but Efficacy for Wrinkles Remains Unverified

To assess limitations in earlier reviews, the analysis considered variations in collagen types, molecular weights, dosages, formulations, treatment durations, and outcome measures.2 The research team conducted a literature search through PubMed, the Cochrane Library, and Google Scholar, focusing on studies published until November 30, 2025. They included human randomized controlled or clinical trials evaluating oral collagen peptides or collagen-based nutricosmetic supplements against a placebo or control group, excluding studies on topical collagen, those with significant coadministration of other active ingredients, or participants with skin disorders.

The analysis sought objective metrics such as skin hydration, elasticity, wrinkle depth or count, and dermal collagen content. Secondary outcomes assessed included skin thickness, transepidermal water loss (TEWL), and adverse events. Researchers employed various methodologies, such as multilevel meta-analysis and sensitivity analyses, to test the robustness of their findings.

The most consistent results indicated improvements in physiological measures due to oral collagen. The standardized mean differences (SMD) reported were 0.44 for hydration, 0.62 for elasticity, and -0.39 for TEWL, suggesting significant enhancements in these areas. Further sensitivity analyses confirmed these findings, particularly for elasticity and TEWL, showing an SMD of 0.81 for elasticity and -0.32 for TEWL at the 12-week mark. Treatment duration appeared more critical than dosage, as meta-regression did not demonstrate a significant relationship between daily collagen intake and outcome improvements. Enhancements in skin hydration were evident as early as four weeks, while elasticity benefits were primarily observed after 12 weeks; higher doses did not correlate with greater improvements.

In contrast, results for visible wrinkles and structural aspects of the skin were less definitive. Initial analyses hinted at potential benefits for wrinkles and skin density, but these claims lost robustness following sensitivity testing. The multilevel analysis yielded an SMD of -0.02 for wrinkles, while any positive effect related to skin density was deemed likely a type I error. The authors concluded that there is insufficient evidence to support reliable structural benefits in these areas.

Widespread publication bias was noted, indicating that smaller negative studies might be underrepresented. However, even after adjusting for this missing data, no significant improvements in wrinkle outcomes were observed, reinforcing the conclusion of minimal effect in this area.

Overall, the findings imply that oral collagen peptides are most effective for enhancing skin hydration, elasticity, and barrier function rather than inducing visible structural changes like wrinkle reduction or dermal densification. The authors highlighted that variability among collagen formulations and measured outcomes, alongside predominantly short study durations, limit the interpretation of structural results. They called for more standardized formulations, uniform outcome measures, and studies extending at least 24 weeks to accurately evaluate the long-term impacts of oral collagen supplementation.

References

1. Batool A, Abbas MS, Farooq R, et al. Oral Collagen Peptides and Skin Rejuvenation: A Systematic Review and an Updated Meta-Analysis of Randomized Controlled Trials. J Cosmet Dermatol. 25, no. 7 (2026): e71041. doi:10.1111/jocd.71041

2. Myung SK, Park Y. Effects of Collagen Supplements on Skin Aging: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Am J Med. 2025;138(9):1264-1277. doi:10.1016/j.amjmed.2025.04.034