Collagen Peptide Supplements Improve Skin Elasticity in a Placebo-Controlled Trial
Taking 2.5 g or 5.0 g of collagen peptides daily for 8 weeks significantly improved skin elasticity in women, with benefits lasting even after they stopped taking the supplement.
Quick Facts
What This Study Found
Oral supplementation with specific collagen peptides (2.5 g or 5.0 g daily for 8 weeks) significantly improved skin elasticity compared to placebo in women aged 35–55. The improvement was statistically significant in both dosage groups, and the effect persisted even 4 weeks after supplementation ended — particularly in older women.
Skin moisture and transepidermal water loss showed positive trends in subgroup analyses but did not reach statistical significance overall. No side effects were reported throughout the study.
Key Numbers
n=69 · 2.5 g and 5.0 g daily doses · 8-week treatment · significant elasticity improvement vs placebo · effect persisted 4 weeks post-treatment
How They Did This
Double-blind, placebo-controlled trial. 69 women aged 35–55 were randomized into three groups of 23: 2.5 g collagen hydrolysate, 5.0 g collagen hydrolysate, or placebo, taken once daily for 8 weeks. Skin elasticity, moisture, transepidermal water loss, and roughness were measured at baseline, 4 weeks, 8 weeks, and 4 weeks after stopping supplementation.
Why This Research Matters
This is one of the earlier well-designed RCTs demonstrating that orally ingested collagen peptides can measurably change skin properties. The fact that improvements in elasticity persisted after supplementation stopped suggests the peptides may stimulate longer-term changes in the skin's collagen matrix rather than just providing a temporary effect.
The Bigger Picture
Collagen supplements are one of the most popular anti-aging products on the market, but for years the evidence behind them was thin. This study was among the first rigorous, placebo-controlled trials to show that specific collagen peptides taken orally can measurably improve skin elasticity — not just in theory, but in objective measurements. It helped shift the scientific conversation from skepticism toward evidence-based acceptance of oral collagen for skin health.
What This Study Doesn't Tell Us
Small sample size of only 69 participants (23 per group). Only women were included, so results may not generalize to men. Subgroup findings on moisture and water loss did not reach statistical significance. The study was 8 weeks long, which may not capture long-term effects or safety.
Questions This Raises
- ?Would longer supplementation periods produce even greater or more lasting improvements in skin elasticity?
- ?Do these benefits extend to men or to populations outside the 35–55 age range?
- ?Which specific collagen peptide sequences are responsible for the skin elasticity effects?
Trust & Context
- Key Stat:
- Elasticity improved at both doses Both 2.5 g and 5.0 g daily collagen peptide doses produced statistically significant skin elasticity improvements versus placebo over 8 weeks
- Evidence Grade:
- This is a double-blind, placebo-controlled randomized trial — one of the stronger study designs. However, the sample size is small (69 participants), and some secondary outcomes did not reach significance, so the evidence is rated moderate rather than strong.
- Study Age:
- Published in 2014. This was a pioneering study in oral collagen peptide research, and its findings have been supported by subsequent larger trials. The core results remain relevant.
- Original Title:
- Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology: a double-blind, placebo-controlled study.
- Published In:
- Skin pharmacology and physiology, 27(1), 47-55 (2014)
- Authors:
- Proksch, E, Segger, D, Degwert, J, Schunck, M, Zague, V, Oesser, S
- Database ID:
- RPEP-02478
Evidence Hierarchy
Frequently Asked Questions
Did both collagen doses work equally well?
Both the 2.5 g and 5.0 g daily doses produced statistically significant improvements in skin elasticity compared to placebo. The study did not find a clear dose-dependent effect between the two active groups.
Did the skin improvements last after people stopped taking the supplement?
Yes. When researchers measured skin elasticity 4 weeks after supplementation ended, the collagen groups still showed higher elasticity than placebo — especially among the older women in the study.
Read More on RethinkPeptides
Cite This Study
https://rethinkpeptides.com/research/RPEP-02478APA
Proksch, E; Segger, D; Degwert, J; Schunck, M; Zague, V; Oesser, S. (2014). Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology: a double-blind, placebo-controlled study.. Skin pharmacology and physiology, 27(1), 47-55. https://doi.org/10.1159/000351376
MLA
Proksch, E, et al. "Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology: a double-blind, placebo-controlled study.." Skin pharmacology and physiology, 2014. https://doi.org/10.1159/000351376
RethinkPeptides
RethinkPeptides Research Database. "Oral supplementation of specific collagen peptides has benef..." RPEP-02478. Retrieved from https://rethinkpeptides.com/research/proksch-2014-oral-supplementation-of-specific
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.