Joint supplements usually combine some of glucosamine, chondroitin, MSM, collagen and turmeric. They are generally well tolerated, and the evidence that they help is mixed and modest rather than clear. Some people report benefit; trial results have been inconsistent.
Two things are worth knowing before starting one: glucosamine is often derived from shellfish, and both glucosamine and chondroitin have been linked to raised INR in people on warfarin.
Common side effects reported with this supplement or ingredient
- Nausea, heartburn or stomach discomfort, less likely when taken with food
- Loose stools or constipation
- Headache
- Drowsiness or difficulty sleeping
- Skin rash or itching
Turmeric or curcumin in a joint formula carries its own considerations, including a bleeding tendency at higher intakes and rare reports of liver injury. See turmeric side effects and MSM side effects.
Possible interactions with medicines, chronic conditions or pregnancy
- Warfarin. Glucosamine and chondroitin have both been associated with raised INR and bleeding. If you take warfarin, do not start a joint supplement without telling the clinic managing your INR. See warfarin side effects.
- Shellfish allergy. Glucosamine is commonly made from shellfish shells. Products made without it exist, so read the label rather than assuming.
- Diabetes. Whether glucosamine affects blood sugar is debated and any effect appears small, but it is reasonable to watch your readings when starting.
- Pregnancy and breastfeeding. There is not enough evidence to establish safety, so these products are generally avoided.
Who should speak to a healthcare professional before using it?
Anyone whose joint pain is getting worse rather than staying the same. A supplement is a reasonable thing to try for long-standing wear-and-tear joint pain. It is the wrong response to a joint that is hot, swollen, locking, giving way, or painful at night and at rest, because those point to something that has a name and a treatment.
Inflammatory arthritis in particular does better the earlier it is treated, and months spent on a supplement are months not spent on treatment that changes the outcome.
Also speak to someone first if you take warfarin or another blood thinner, have a shellfish allergy, have diabetes, or have liver disease.
Dose, product-quality and stacking risks
Joint formulas often overlap with turmeric capsules, omega-3 and collagen taken separately, which means doubling up on the same ingredients. Trials of these products generally ran for months, so if you are going to try one, give it a fair trial and then stop if nothing has changed rather than continuing out of habit.
Supplements in South Africa are regulated as complementary medicines, and the checks applied are not the same as those for prescription medicines. See how supplements are regulated in South Africa.
When to stop and get medical advice
Emergency care for swelling of the face, lips or throat, difficulty breathing, or a widespread rash after a dose.
Stop and seek advice for unusual bruising or bleeding, blood in urine or stool, yellowing of the eyes or skin, dark urine, or persistent nausea.
Tell your doctor and pharmacist what you take, including supplements. Most people leave supplements off the list because they do not think of them as medicines, and that is exactly how avoidable interactions get missed.
Related supplement safety guides
- Supplement side effects
- Supplement and medicine interactions
- Taking too many supplements
- When to see a doctor about a supplement
- Report a supplement side effect
See also muscle and joint medicine side effects.
Medical Disclaimer: This content is for informational and educational purposes only and does not constitute medical diagnosis, prescription, or professional advice. Always read the patient information leaflet and consult a qualified doctor or pharmacist regarding any medicine or health concern.