I am also curious about this. I know many people like taking oral Glutamine, but every decent study I have seen on its nitrogen retention benefits involves an injectable form.
I do take oral Glutamine becuase it is relatively cheap, but I doubt it has much real affect.
why cant it work via injection? is it too small of a dosage that needs to be continuously feed into the bloodstream? thats the only reason can think of. not trying to argue, merely asking for my own sake. thanks