Flex Free Original Formula is a rich source of purified chondroitin sulfates blended in a delicious easy-to-feed base of alfalfa meal, vegetable oil and flavorings. Chondroitin sulfates are members of the family of natural body lubricants known as glycosaminoglycans, or GAGs. They are produced in the bodies of horses, humans, and most other animals. As crucial elements of connective tissue and structural cartilage, chondroitin sulfates are involved in the bonding of collagen fibers and the retention of moisture in the cartilage tissue. Chondroitin sulfates are also found in the skin, blood vessels, and other types of connective tissue. Flex Free works to replenish these valuable nutrients throughout your horse's body.