I used it when on test prop (250 mg a wk), Reforvit (25mg pill a day), and HGh (4 I.U. a day) and did not gain too much fat (think HGh lowers your insulin sensitivity). I got up to 10 I.U. a day, after workouts, but it was hard to keep my meals so timed out. So I only stayed on it for a week...