Hmm im not sure but I used sand clear on one of my mares a while back, it worked, if I could get her to eat it... I would mix it in with some sweet and somehow she would figure out how to eat everything but the sand clear... even though its like really small like sand almost lol.. so sooner or later I started to put some syrup in the mix so that the sand clear would stick to the sweet feed:) then it started working..
Metamucil has the same active ingredient, psyllium fiber, as Sand Clear. There's no reason to pay 3 times as much for the same product. I buy Walmart's Equate brand. Works just as well as the higher priced stuff.