Doctor's Best Vegan Glucosamine Chondroitin MSM (GCMSM) contains three ingredients known to support healthy joints and joint function: glucosamine, chondroitin and MSM (methylsulfonylmethane). This unique combination uses GreenGrown® 100% vegetable source glucosamine sulfate, highest purity OptiMSM®, and Mythocondro®, the first formulation to contain non-animal chondroitin sulfate. Non-animal derived chondroitin provides greater concentration and 43% higher absorption than chondroitin sulfate of animal origin. Vegan GCMSM (OptiMSM®) supplies the building material for proteoglycans, a component of cartilage that helps support joint structure and function. It also provides sulfur, the key element for joint health, hair, skin, and nails. GreenGrown® Glucosamine and Mythocondro® Chondroitin are both manufactured by environmentally-friendly, patented fermentation technology and are suitable for vegans.