Everyone is different I've been on gh for 4yrs with maybe a month or two off when I started I ran humatrope and nutropin aq and saw great results with 3iu ed but since I've switched to many different generics and still see and feel results but I run 5 to 6 iu with them. I've gone as high as 12iu but to me the results didn't match the cost . I've been on grey tops for awhile and they seem to be on point. Hands down the nutropin aq pen carts were amazing to say the least. For me other compounds come in to play for my gh results slin/test/t3 all change the game when added for me