I'm another nearly zero side effect GH user. I had never even tried it until this past March/April, and started at 3iu. I felt the tingling arms and hands at night a little, happened maybe twice initially, and once in a while with dose increases . I've since gone all the way up to 18iu to asses tolerance, all with minimal to no sides. Just tingling fingers at night a few times as I was increasing doses. I'm at 14iu/night right now with zero sides. I'm glad on the one hand, but being able to take this much makes you want to take this much, and it's definitely a cost that adds up. I'll probably settle on 12iu as a cost/benefit dose for the next few years. Really glad I took the plunge, the 24/7 muscle fullness is something I've always sought, but couldn't quite achieve by other means.