I casually asked my doctor yesterday (who knows I juice and even advocates it) if there was any advantage to reconstituting my growth hormone with bacteriostatic water rather than the sterile water that comes with the kit. He basically told me, that if bacteriostatic water worked better, it would have been included in the GH kit to begin with. It was his opinion that as long as the GH is refrigerated after constitution it should be good for 6 or 7 days, which is longer than it takes to use the whole thing anyway. He claims that the reason the instructions say to use within 24 hours is because the GH is prescribed for AIDS patients who already have immune deficiencies and is basically a liability issue.....People with healthy immune systems shouldn't have any problems with a refrigerated sterile water solution according to him. His main point was, the people at Serono determined that sterile water works best with Serostim.....so use it.