I also tried the smarttendon for awhile but it was slightly more expensive..and had half the amount of MSM that the Smart MSM had. I thought she responded better to the higher amount of MSM, and since I also have a couple more horses on supplements (have a easy keeper on their ez keeper supplements to ensure he gets what he needs) it worked better for me and she loves the taste of the pellet version they have. And I love the smartpaks..very convenient and if someone else has to ever feed my horses, already measured and their name is on the package. And even though you are getting the reoccuring smartpaks, its easy to change it to something else the next month if the MSM isnt working, but I know it will help. And they have various supplements to try in a vast range of prices, which I think is great.