collagen supplements side effects
Itâs not clear what the side effects might be. Other collagen products, such as bovine collagen and gelatin, have caused allergic reactions. Since collagen type II contains chondroitin and glucosamine, large doses might lead to the same side effects as those seen with chondroitin and glucosamine supplements. These side effects include nausea, heartburn, diarrhea and constipation, drowsiness, skin reactions, and headache.