Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Common side effects may include:
gas, bloating, heartburn, stomach cramps, nausea;
headache, drowsiness;
diarrhea, constipation;
swelling in your ankles or feet;
itching, skin irritation; or
puffy eyelids.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Chondroitin/glucosamine/methylsulfonylmethane side effects (more detail)
