I've asked this question in similar site, but never got an answer. I've been toying with the idea of dropping bacteriostatic water and purchasing 5 mls of sodium chloride to mix with my HCG which I've read may extend the shelf life. This is contrary to everything I've ever read on gear forums saying you should use bacteriostatic water so I figured I'd ask before I tried it. I want the product to last longer so that I can run it at a lower dose throughout the cycle. I can only get it in 5,000 iu so it's either blast at the end or spend more money than I want to and throw half of it away. Thanks!