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10 October 2026

Oral collagen peptides: what 26 randomised trials show for skin hydration and elasticity

Q: Do oral collagen peptides have an effect on the skin?

In the meta-analysis of 26 randomised studies, skin hydration and elasticity improved statistically significantly compared with placebo. These are instrument-based measurements over a maximum of twelve weeks; the paper contains no pooled analysis of wrinkles.

Q: Which dose and which collagen source are best?

This cannot be derived from the data. Doses ranged from 372 mg to 12 g per day; for bovine, porcine and chicken collagen, only one study each was available.

Q: How long do collagen peptides have to be taken?

Effects on skin hydration were measurable from about four weeks. The paper's subgroup comparisons do not show that longer intake works better; no study ran for longer than twelve weeks.

Oral collagen peptides: what 26 randomised trials show for skin hydration and elasticity

Peptides are among the most heavily advertised active ingredients in aesthetics: signal peptides in serums, “Botox-like” peptides in creams, copper peptides – and oral collagen peptides. Patients ask about them in consultations, and the advertising promises are big. For peptides in creams and serums, there have so far been only a few controlled studies. The best studied is hydrolysed collagen, i.e. collagen peptides as a dietary supplement. A meta-analysis from Taiwan has summarised the randomised studies on this.

Study design

The team led by Pu searched PubMed, Embase and the Cochrane Library up to December 2022 for randomised controlled trials in which healthy adults took hydrolysed collagen or placebo. A total of 26 studies with 1,721 participants were included, almost exclusively women aged between 21 and 70 years.

Dose: 372 mg to 12 g per day.
Duration: 2 to 12 weeks.
Source of collagen: fish (14 studies), porcine (2), bovine (1), chicken (1), not specified (9).
Outcome measures: skin hydration (predominantly Corneometer) and elasticity (Cutometer).

A random-effects model was used; risk of bias was assessed with the Cochrane RoB 2 tool.

What did the meta-analysis find?

Skin hydration: standardised mean difference (SMD) 0.63 (95% confidence interval 0.38 to 0.88; p < 0.00001) – 494 people on collagen, 460 on placebo.
Elasticity: SMD 0.72 (0.40 to 1.03; p < 0.00001) – 590 versus 555 people.
Time course: For skin hydration, an effect was seen after 4 weeks (SMD 0.36), 8 weeks (0.81) and 12 weeks (0.48). The comparison of “longer than 8 weeks” versus “shorter” was not significant (p = 0.26; for elasticity p = 0.77).
Collagen source: For fish collagen, the effect on skin hydration was significant (SMD 0.49; 0.20 to 0.78). For bovine, porcine and chicken collagen, only one study each was available – without a significant result.

Assessment: what the figures mean – and what they do not

Measurements, not wrinkles: The effects are considered moderate in size but relate to instrument-based measurements. The paper contains no pooled analysis of wrinkles, visible outcome or safety.
Inconsistent studies: Heterogeneity is high (I² 70% and 84%, respectively); dose, composition and duration differ widely.
“Longer is better” is not proven: The authors consider longer intake to be advantageous – their own subgroup comparisons do not support this.
Risk of bias: In 13 of the 26 studies, there were concerns about missing follow-up data. Whether the funding of the individual studies influences the result was not investigated; no protocol registration is stated.
Short duration: No study ran for longer than twelve weeks; what happens after discontinuation remains open.

Conclusion for practice

In randomised studies, oral collagen peptides measurably improve skin hydration and elasticity compared with placebo – studied over a maximum of twelve weeks and almost exclusively in women. A specific dose or collagen source cannot be derived from this, and an effect on wrinkles is not demonstrated by this paper.

In our view, collagen peptides are therefore a topic for honest counselling: a low-risk supplement with a moderate, measurable effect – not a substitute for medical procedures. Anyone who wants to assess the evidence behind treatments with confidence will find the fundamentals in our online courses.

Frequently asked questions

Do oral collagen peptides have an effect on the skin?

In the meta-analysis of 26 randomised studies, skin hydration and elasticity improved statistically significantly compared with placebo. These are instrument-based measurements over a maximum of twelve weeks; the paper contains no pooled analysis of wrinkles.

Which dose and which collagen source are best?

This cannot be derived from the data. Doses ranged from 372 mg to 12 g per day; for bovine, porcine and chicken collagen, only one study each was available.

How long do collagen peptides have to be taken?

Effects on skin hydration were measurable from about four weeks. The paper's subgroup comparisons do not show that longer intake works better; no study ran for longer than twelve weeks.

Reference: Pu SY, Huang YL, Pu CM, Kang YN, Hoang KD, Chen KH, et al. Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis. Nutrients. 2023;15(9):2080. doi: 10.3390/nu15092080. PMID 37432180. Open access (CC BY 4.0): PMC10180699.