Collagen supplements may offer real benefits, major reviews suggest

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

A new review of the evidence—pooling data from 113 clinical trials—suggests that for some health outcomes, the answer is probably yes.

But as with nutritional science, the full picture is more complex.

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

Not all collagen is the same though. Collagen found naturally in foods may be less well absorbed than the smaller forms used in many supplements.

These hydrolyzed forms – where the protein is broken down into short chains called peptides – are thought to enter the bloodstream more easily and make 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 through March 2025, drawing on 16 systematic reviews that included nearly 8,000 participants between them. The overall picture was cautiously positive.

Collagen supplementation was associated with moderate improvements in muscle health and reduced pain in people with osteoarthritis.

There were also improvements in skin elasticity and hydration – although these benefits occurred gradually, suggesting that long-term, sustained collagen intake is more important than a short-term flare-up.

Some findings were less clear. Skin elasticity and hydration results vary depending on when the studies are done, with newer research showing lower improvements in elasticity but greater improvements in hydration.

This contradiction is remarkable—it suggests that science is still resolving.

The quality of the research itself is also worth evaluating. Studies have used multiple methods, doses, and methods to measure outcomes, which makes direct comparisons difficult.

Fifteen of the 16 included reviews were rated as low or seriously low quality – not necessarily because the supplements don’t work, but because of methodological problems such as studies not being pre-registered and poor reporting on potential biases.

Most trials were also short and involved 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 greatly. 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 have used oral supplements, while others have tested collagen dressings on the skin.

The way collagen is processed also affects the size and composition of the peptides in the final product, which in turn affects how it behaves and is absorbed in the body. Combining all these different products into a single analysis is as risky as it appears.

Individual differences are also important. Factors such as sun exposure, smoking, sleep quality, environment and hormone levels all affect how skin ages and how it responds to supplements.

If studies fail to account for these variables, it becomes very difficult to know which observed changes are truly due to collagen or simply reflect differences in the participants’ lifestyles.

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This review adds to the growing body of evidence suggesting that collagen supplements are not simply expensive placebos. It appears to have real, if modest, benefits – especially for skin hydration, joint pain and muscle health.

The research base still has significant gaps. Without more rigorous, standardized studies, it’s really hard to say what those benefits are, or who is seeing them.

Studies are needed to clearly define the type of collagen used, the dose, how it is distributed and the characteristics of the people taking it.

Haba GhazalKingston University Senior Lecturer, Pharmacy

This article is republished from The Conversation under a Creative Commons license. Read the original article.