A few weeks ago I had an appointment with an endocrinologist, and she had checked my bloodwork, and told me my estrogen levels were on the lower end of the normal range, and wanted to put me on patches to bring my levels up a bit. While I was living in the States I was on Estrace tablets, sublingually dissolving them. My levels under this method were moderately high and my endo and I were happy with the results. When I moved to Finland, I started on Progynova as Estrace isn't anywhere to be found here. The tablets are coated, which makes dissolving them sublingually less of an option. My bloodwork here suggests that my levels dropped on them.

I have been severely depressed for the last year or more. We thought my depression was due to my antidepressant not being effective anymore. We switched me to a new antidepressant and it didn't do much good over several weeks of adjustment. When I started with the Estradot patches, I didn't give much thought to it, I just put the patch on and forgot about it. Fast forward 8 hours later, and my wife were having a conversation and she mentions to me that my mood was the best she's seen in months. My mood seems to be carrying over the next couple days as well, and it's better than it has been in a long time.

Is it possible that the increase in estrogen is really causing a mood change this quickly?

Perhaps. I know of some studies where women with post-partum depression and/or psychosis improved quite rapidly upon taking either estradiol patches or sublingually. No anti-depressant or antipsychotic worked but estradiol did!