Ultra-Pure MSM for pets only uses OptiMSM which is the premier product for healthy joints and mobility. Sulfur, a key component of Ultra-Pure MSM for pets, supports joint, cartilage and connective tissue to sustain an active lifestyle for dogs and cats. MSM benefits overall joint health and normal range of motion to stay active. MSM plays a role in maintaining the cushion between joints to support mobility and protect healthy cartilage. It also supports synovial fluid production to keep joints lubricated. Choosing Ultra-Pure MSM from NWC Naturals Inc. will guarantee you are getting genuine OptiMSM. Please NOTE: NWC Naturals Inc. products may NOT be sold on any third-party platform. NO Amazon, Walmart, eBay, Jet, Target, Rakuten and so forth.