I am currently taking HGHpro by Anabolic Innovations. It contains 600mg GABA per serving. Hard to say what is giving me the biggest effect as it contains multiple ingredients including Alpha-Size, but the sleep has been pretty top notch on it. I have alot of problems with sleep so it has been good for me. As for GH properties, I am not sure if I have have a raise in GH, but my recovery has been off the charts. Might be because of the increased sleep though, so who knows.