Short answerMaybe a little, but the evidence is uneven. Pooled results show some benefit on one pain scale and none on another, and many trials were small.
Not enough evidence yet
What it is
Collagen is the main protein in cartilage, tendon and bone. Supplements are made from animal sources and sold as powders and capsules. Some are broken into small pieces, called hydrolysed collagen, and some are left whole. The idea is that eating collagen gives the body material to repair cartilage.
What the research shows
pooled the placebo controlled trials of collagen for arthritis. Taken together, collagen lowered the total score on a standard arthritis questionnaire and lowered pain on a visual scale by about 17 points on a 100 point scale. But on the pain and function parts of that same questionnaire, the difference from placebo was not significant. Only stiffness improved.
Results varied a lot between trials, doses and products differed, and many trials were small and short. Some were run or paid for by the companies that sell the products. A bigger and more independent trial is needed to know whether the benefit is real. also found that no supplement showed a lasting effect.
Risks and effort
Collagen supplements are generally well tolerated. Some people get a bloated or full feeling or a bad taste. Check the label if you have a fish or shellfish allergy, because some collagen comes from marine sources.
What usually works instead
Exercise and strength work for the leg muscles, and weight loss where that applies, have the best evidence. Anti-inflammatory gels and tablets can also help for a while. See Osteoarthritis of the Knee and Does exercise work for knee arthritis?.
Questions people ask
Does collagen rebuild cartilage?
No trial has shown that it does. The studies measured pain and function, and not new cartilage.
Is hydrolysed or undenatured collagen better?
Both types have been studied in small trials. There is not enough evidence to say that one works better.
Is collagen for skin and for joints the same thing?
The product may be the same, but the research is separate. Skin studies do not show what it does for a knee.
How long should I try it for?
Most trials ran for three to six months. If you try it, give it that long and stop if you notice no change.
Sources
Select a source to read what the study or guideline found, in plain words, with a link to the original.
Last reviewed 24 October 2026. Next review due October 2027.
