Hi EllaAurora, I've seen this on another thread and meant to reply but I forgot. Foggy brain these days. As far as I know, and trust me, I have been reading a lot about all types of HRT, the gel is 'the same', and I'm quoting it because one can never know unless you have access to the pharmaceutical company. 17-beta estradiol is the same as estradiol hemihydrate, at least when it comes to its function as a hormone. Regarding absorption it can be tricky. I've only read one article about this and it's very technical. I can post a link if you're interested. That said, there's a possible different explanation for different experiences with the 'new' Oestrogel. The PIL has been changed recently. Now it says they can be manufactured by Delpharm (Belgium) or Besins, so maybe there are minor but still important differences between them. I have read on an old thread (can't remember which one right now) that Besins intends to bring the manufacturing process back to France. Hope this helps. Cheers.