I am using it on two of mine, one a mare that used to tye up, I think it has helped as touch wood she hasn't since I've started using it and I feed it to my other horse because he is on a lot of improvised linseed and was advised to use it.
I am using it for my EMS pony over the winter. She has soaked hay and has been on a weight loss plan for about a year. I use Equimins vitamin E and selenium.