I haven't had anyone on it in a long time but when we put an old pony on it, within days, everywhere he rolled looked like it had snowed, from him shedding his long hair. Didn't take long at all for that result.
Cool!! This will be his 3rd day today! He is on a very low dose, 1/2 teaspoon a day. Will check bloodwork in 30 days and change him accordingly. He has always been lethargic and has had fat pockets and never really had a good summer coat, but did shed out but with blotchy patches of hair left. He did have lyme disease and has been treated for that, and also has IR, but diet and excercise has left him 150lbs lighter, but still cresty and fat deposits. T4 was below the range, so we are treating him.