I used the nutropin and the supra and they are interchangeable. The supra is half the cost and much easier to obtain. I looked all over before I found nutropin sources and they were in the clouds with their pricing. When I switched to Supra I was in the middle of healing from a bone fusion and the healing process didn't slow at all and the usual sides I get of joint pain in my hands was still present. So in my opinion, like I said, they are the same.