Collagen supplements can help your skin and joints, large new study finds

Collagen supplements have become one of the bestselling products in the wellness industry, promising everything from smoother skin to stronger joints. But do they actually work?

A major new review of the evidence – pulling together data from 113 clinical trials – suggests that, for some health outcomes, the answer is probably yes. But as ever with nutrition science, the full picture is more complicated.

Collagen is a protein the body makes naturally. It gives skin its structure and elasticity, supports bones and muscles, helps wounds heal and plays a role in protecting organs. The problem is that production slows as we age, which is why so many people turn to supplements to top it up.

Not all collagen is the same, though. The collagen found naturally in food may be less well absorbed than the smaller forms used in most supplements. These hydrolysed forms – where the protein has been broken down into shorter chains called peptides – are thought to pass more readily into the bloodstream and making it easier for the body to transport these fragments to tissues where they may have biological effects, potentially supporting skin, joint and muscle health.

The new review examined research published up to March 2025, drawing on 16 systematic reviews that between them included nearly 8,000 participants. The overall picture was cautiously positive.

Collagen supplementation was linked to moderate improvements in muscle health and reduced pain in people with osteoarthritis. There were also improvements in skin elasticity and hydration – though these benefits built up gradually, suggesting that taking collagen consistently over a longer period matters more than a short-term burst.

Some of the findings were less clearcut. Results for skin elasticity and hydration shifted depending on when the studies were conducted, with newer research showing lower improvements in elasticity but greater improvements in hydration. That inconsistency is worth noting – it suggests the science is still settling.

The quality of the research itself is also worth scrutinising. The studies used a wide variety of methods, doses and ways of measuring outcomes, which makes direct comparisons difficult.

Fifteen out of the 16 reviews included were rated as low or critically low quality – not necessarily because the supplements don’t work, but because of methodological problems such as studies not being registered in advance and poor reporting on potential biases. Many trials were also short and included few participants, which limits what we can reliably conclude about long-term effects.

Not all collagen is equal

Part of the problem is that collagen supplements vary enormously. Some are derived from animals, such as cows, pigs and chickens, and others come from marine sources, including fish, jellyfish and shellfish. There are even so-called “vegan” collagen alternatives. Some studies used oral supplements, while others tested collagen dressings applied to the skin.

The way collagen is processed also affects the size and composition of the peptides in the final product, which in turn influences how it behaves and is absorbed in the body. Lumping all these different products together in a single analysis risks obscuring as much as it reveals.

Individual differences matter too. Factors such as sun exposure, smoking, sleep quality, environment and hormone levels all affect how skin ages and how it might respond to supplementation. If studies fail to account for these variables, it becomes very difficult to know whether any observed changes are genuinely due to the collagen or simply reflect differences in participants’ lifestyles.

This review adds to a growing body of evidence suggesting collagen supplements are not simply expensive placebos. There appear to be real, if modest, benefits – particularly for skin hydration, joint pain and muscle health.

The research base still has significant gaps. Without more rigorous, standardised studies, it remains genuinely difficult to say what is driving those benefits, or who is most likely to see them. Studies need to clearly specify the type of collagen used, the dose, how it was delivered and the characteristics of the people taking it.

Heba Ghazal does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.