MEGA Grand Flex™ is an ideal equine joint supplement for senior horses, competition horses, and horses in various disciplines. We recommend using MEGA Grand Flex when a more aggressive approach is needed. MEGA Grand Flex contains all the important co-factors contained in original Grand Flex, plus 12,500 mg of Glucosamine and 10,000 mg of MSM per measure to promote healthy joint function. For a more powerful approach, Grand H.A. can be added, or you can switch to Grand H.A. Synergy. When results have been achieved, it may not be necessary to use MEGA Grand Flex on a long-term basis; we recommend following with our original Grand Flex, Grand Complete, or Grand H.A. for long-term maintenance and joint support.