GLC 5500 Powder (2 lbs.) The Only Full Spectrum Glucosamine + Chondroitin is fully patented and 100% pure. Our pharmaceutical- grade composition of all four bio-available glucosamines optimizes cartilage repair and hydration by elevating and sustaining levels more effectively than any other brand. Unlike other products that substitute perna mussels or unproven herbal agents in place of true chondroitin sulfate, GLC 5500 contains clinically proven CS A-4 to help reduce degenerative enzymes and speed healing. Athlete or old family friend, you demand the best for your horse, and GLC 5500 delivers!