What Are the Side Effects of Glucosamine and Chondroitin?

Glucosamine and chondroitin are safe and effective supplemental drugs for arthritis. However, there are some uncommon and usually gentle side effects.

Glucosamine is an important element in cartilage repair and production. A decreased supply of glucosamine may cause a delay in cartilage repair, which will later result in cartilage damage. It is safe to take glucosamine supplements for long periods of time. Glucosamine is best taken with chondroitin; it is effective in relieving pain caused by arthritis.

Glucosamine side effects

• Over-dosage of glucosamine may cause gastric upset such as soft watery stools and nausea. It also causes indigestion and heartburn. For that reason, glucosamine should be taken with foods.


• Glucosamine is extracted from shellfish. If you are allergic to shellfish, you must first consult your doctor before taking any glucosamine supplements.


• Glucosamine has no proven undesirable effects to pregnant women; however, it is still recommended to consult your physician first.


• Resistance in insulin production might happen when taking glucosamine. It lessens the process of insulin metabolism. Glucosamine is classified as a carbohydrate, but the body cannot break down this carbohydrate into glucose, so it does not contribute to the increase of blood sugar in the body. On the other hand, there are issues that influence secretion of insulin and levels of blood glucose in the body. It is highly advised to check the blood sugar level when taking glucosamine supplement.

The side effects of glucosamine and chondroitin are considered mild, but to prevent them precaution is still suggested.

Chondroitin is taken from the windpipe of cattle or from shark cartilage. Protoglycans are the product of chondroitin sulfate and proteins in the body. Protoglycans are the substance surrounding the cartilage, ligaments and tissues. Thus, chondroitin protects the cartilage and helps in reduction of pain and inflammation.

Chondroitin side effects

• Like glucosamine, chondroitin can also cause gastric upset when taken orally.


• Some testimonies include irregular heartbeat and hair loss.


• Chondroitin via optical drops can increase the possibility of having an intraocular hypertension, which is a critical condition. A short-term swelling on the cornea may also occur.


• Chondroitin reacts with NSAIDs drugs and anticoagulant medications, so mixing of these medications may be risky. First consult your doctor before taking chondroitin with NSAIDs and anticoagulants.


• Chondroitin glucosamine side effects also include upset stomach, diarrhea or constipation.


• Chondroitin is not recommended for lactating and pregnant women, same as glucosamine.


• Other side effects of chondroitin are swelling of the ankles and eyelids.