I've tried just about every kind of gh known to medical science. (And probably some UNKNOWN to medical science!) Been on gh for about 5 years now, including Equigen a couple of times. Frankly for me if its all been exactly the same (as long as its real). I've never heard of anything to indicate that the different "brands" have different effects. Hell, Saizen and Serostim are both made by Serono. As far as I know the only possilbe chemical difference in gh's would be the deal about whether its 191 or 192 amino acid chain. I think now its all 191. Maybe some people have experienced differences in effect, but I honestly would be surprised if there is much in reality. Its not like the difference between say, dbol, deca and test cyp which of course while all three are AAS, ARE very different chemically and in many other ways, including duration of effect. Gh is all made from the identical recombinant dna process. There is some difference in them as to their storage. Some (like Pharmacia's Genotropin) have to be refrigerated before reconstitution, and some (like Serostim and Saizen) only have to be refrigerated after reconstitution. Maybe this means they are different somehow? Anyway, I personally think gh is gh. Maybe one of the real gh experts like BigA can shed some light?