Sterile water is water that doesn’t have any microorganisms, also known as ‘microbes’, in it. … Bacteriostatic water is sterile water that contains a bacteriostat, a chemical that prevents the growth of bacteria in the vial. The bacteriostat used is benzyl alcohol. It won’t " kill" bacteria, but you can re enter the vial. Sterile water really should be used once. Hypothetically, if you use sterile water to mix a drug, it should be used once and not really entered again even with a new syringe, but that is to protect different scenarios. I doubt there would be any problems if 10iu vial of hgh was used 3 days, but maybe not so much for a week or more. BAC doesn’t degrade 99% of meds out there.