Most supplements for knee pain have weak or mixed evidence. UK NICE guidelines do not recommend glucosamine or chondroitin for osteoarthritis. Turmeric (curcumin) has some small positive trials. None of them rebuild cartilage.
Evidence summary
| Supplement | Evidence |
|---|---|
| Glucosamine | Large trials mostly no better than placebo; NICE does not recommend |
| Chondroitin | Mixed results; NICE does not recommend |
| Turmeric / curcumin | Some small trials show pain relief; quality varies |
| Fish oil | Weak evidence for knee pain |
| Collagen | Small, mostly industry-funded studies |
Safety
Turmeric and fish oil can interact with blood thinners. Glucosamine is often made from shellfish. Tell your doctor what you take.
If you want to try one, give it 2 to 3 months and stop if nothing changes.