GNC MSM 1000 mg: Supports Joint Cartilage* GNC MSM 1000mg capsules are taken daily to support joint cartilage health. MSM is also known as Methylsulfonylmethane and is a naturally occurring compound that serves as a source of sulfur an essential component of joint cartilage. Supports joint cartilage* 180 Capsules Gluten Free These statements have not been evaluated by the Food & Drug Administration. This product is not intended to diagnose treat cure or prevent any disease.