Zesty Paws Mobility Bites soft chews include premium OptiMSM, BiovaPlex and Serrazimes for deluxe mobility support. Plus, these chewables also include Glucosamine Hydrochloride, Chondroitin Sulfate, Hyaluronic Acid and Zinc Sulfate. These chews help maintain the health, lubrication and resiliency of joints and connective tissue to promote mobility, and they also help maintain healthy cartilage and joint health.