Collagen — what the science says

In a nutshell

For skin, an effect shows up mainly in studies paid for by manufacturers; independent and high-quality studies found none.¹
For joints, collagen eases pain slightly in the short term, but the evidence is of low quality.^2,3
For muscle growth, collagen is a weaker protein than whey.^4,5

1Skin

Moderate evidence 23 studies A summary of 23 randomised trials with 1,474 people: overall, collagen improved hydration, elasticity and wrinkles. But studies not funded by pharmaceutical companies and high-quality studies showed no effect. The authors conclude that evidence for collagen against skin ageing is lacking.¹

2Joints

Weak evidence 69 studies A review of 69 studies of 20 supplements for osteoarthritis: collagen hydrolysate markedly relieved pain in the short term; no supplement had a long-term effect. The quality of the evidence was very low.²

Moderate evidence A summary of studies in osteoarthritis: collagen lowered the overall symptom score (WOMAC) and pain on the VAS scale, but of the sub-scores it improved only stiffness.³

3Muscles and tendons

Moderate evidence — a randomised trial In older women, whey raised muscle protein synthesis more than collagen, which did not raise it at all over the longer term.⁴

A systematic review: 15 g of collagen a day raised collagen synthesis in the body, but not muscle protein synthesis more than higher-quality proteins.⁵

Moderate evidence 19 studies A summary of 19 studies with 768 people: collagen taken during long-term training slightly increased fat-free mass, strength and tendon changes.⁶

What to take from this

Don't buy collagen for your skin with high expectations — independent studies found no effect.¹
As a protein for muscle, whey or ordinary food with protein is better.^4,5
For joint pain it may help a little in the short term, but the evidence is weak.²

Sources

Written on 9 Oct 2026, based on studies available at that date. Newer research may change the conclusions.

Myung S. K., Park Y. (2025). Effects of collagen supplements on skin aging: a systematic review and meta-analysis of randomized controlled trials. Am J Med 138:1264–1277. doi.org/10.1016/j.amjmed.2025.04.034
Liu X. et al. (2018). Dietary supplements for treating osteoarthritis: a systematic review and meta-analysis. Br J Sports Med 52:167–175. doi.org/10.1136/bjsports-2016-097333
García-Coronado J. M. et al. (2019). Effect of collagen supplementation on osteoarthritis symptoms: a meta-analysis of randomized placebo-controlled trials. Int Orthop 43:531–538. doi.org/10.1007/s00264-018-4211-5
Oikawa S. Y. et al. (2020). Whey protein but not collagen peptides stimulate acute and longer-term muscle protein synthesis with and without resistance exercise in healthy older women: a randomized controlled trial. Am J Clin Nutr 111:708–718. doi.org/10.1093/ajcn/nqz332
Khatri M. et al. (2021). The effects of collagen peptide supplementation on body composition, collagen synthesis, and recovery from joint injury and exercise: a systematic review. Amino Acids 53:1493–1506. doi.org/10.1007/s00726-021-03072-x
Bischof K. et al. (2024). Impact of collagen peptide supplementation in combination with long-term physical training on strength, musculotendinous remodeling, functional recovery, and body composition in healthy adults: a systematic review with meta-analysis. Sports Med 54:2865–2888. doi.org/10.1007/s40279-024-02079-0

This is general information and does not replace a doctor. Food supplements are not medicines; buy them from trusted sellers and talk to a doctor if you are ill or take medicines.