from what i understand, there are two main manufacturers of products for AC - one manufactures puregon, cetrotide and pregnyl, the other gonal-f, orgalutron and ovidrel. they're basically exactly the same - the only thing i've noticed from my research is that ovidrel seems to stick around longer in your system so can impact the result of HPT's for longer - but the actual action is basically the same...

HTH hun

BG