It is weird -- the conversion product binds to the receptor with more affinity than GHB itself, but it obviously is not as strong in the real world -- also, its effects among individuals seems to vary much more than with GHB. About 5% or so get basically nothing from it, most get a nice relaxation, then others get fairly twisted, with no real rhyme or reason to it (i.e. it is not just a matter of having used GHB/GBL or other drugs in the past, being larger, etc.)