I can't say that these had the most potent effect in my case, however they appear quite safe while also have a noticeable positive effect. They also proved to be able to increase the ERB:ERa ratio in a study.
https://assets.researchsquare.com/files/rs-1167112/v1_covered.pdf?c=1639668824The research is quite scarce and mostly focuses on soy and red clover even though I don't think these are the best supplements to manage this issue.
I only did short tests with these, but my symptoms were getting better as soon as the first day.
I took 4 mg astaxanthin two times a day and on a separate occasion I took 250 mg Resveratol (Polygonum cuspidatum root extract) also two times a day (morning and evening evidently).
The details are in my summary.
https://poiscenter.com/forums/index.php?topic=3798.0It is true that at menopause estrogens decrease, however a high estradiol level is only one cause for ERa domination, but there could be several other reasons for an altered ERB:ERa ratio. This ratio seems to play a significant role in several other diseases like asthma, multiple sclerosis, breast cancer, prostate cancer, Alzheimer's disease and actually many more, but I guess if so many people had a high estradiol level it would have been noticed already. As both ERa and ERB have about a thousand genes they modulate it is really hard to guess the exact problem. Neverthless the important thing is that treatment-wise most of the selective estrogen receptor modulators (SERM) are beneficial for me. Some of these have only a weak effect like your case with pomegranate, however combining a few of them may have a much better effect.
The ERa-mediated pathway mainly suppresses inflammation and increases cell proliferation, while ERB-mediated processes decrease cell proliferation, but increase cell repair and cell survival, although it is also a major regulator of apoptosis. Of course in other cases the ratio may be altered differently and absolute hormone levels also count. Actually in a high estradiol setting even ERa agonists may theoretically decrease ERa dominance as they could replace estradiol and result in lower activation.
It is really a trial and error method at this point and I am only in the process of figuring this out myself, however I am completely sure that estrogen receptor beta is a major factor in my case and thus likely so in other POIS cases as well.