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.
Elasticity improved at both dosesBoth 2.5 g and 5.0 g daily collagen peptide doses produced statistically significant skin elasticity improvements versus placebo over 8 weeks
What the researchers 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.
Why it 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 numbers in context
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 the study worked
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.
Who was studied
Women aged 35–55 years
What this study cannot 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.
How to read the evidence
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.
When this study was published
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.
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.
Questions still open
- 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?
Common questions
Did both collagen doses work equally well?
Did the skin improvements last after people stopped taking the supplement?
Read the original research
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
Citation
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