There’s no clear-cut answer to this question. The thing is, anabolic steroids are not used in multi-dose vials in medicine — only in ampoules. That’s why there are no official medical guidelines for this. In such cases, we have to rely on the experience of practicing athletes.
From my own experience, if stored properly, a vial can last for a very long time. I’ve personally used vials that had been opened for several years without any problems. However, we can’t be 100% certain it’s safe in every case, and here’s why:
- Each time the stopper is pierced, a small number of bacteria can enter. Some of them will be killed by the benzyl benzoate inside, but there’s no guarantee.
- Air also enters through punctures, causing the oil to oxidize. Oxidized oil usually turns dark, almost black, and such a product should not be used.
I know people who have used oxidized oil — nobody died, but the PIP (post-injection pain) was significant.