Red clover and Black Cohosh were the menopause supplements popular when I went thru menopause 20 years ago. I found much relief from hot flushes etc with Remifemin which is refined Black Cohosh.
However I’d be very wary about taking a phytoestrogen if you had Er+ breast cancer as the hormone therapy is designed to knock off the oestrogen that caused the cancer.Maybe as a start check the Herbs app to see what it says about the ingredients and definitely talk to your oncologist before going down this path.
I tend to agree with @Zoffiel and think it may be just a marketing ploy on behalf of the company.I seem to remember major concerns from the medical profession years ago about Black Cohosh but not sure why as Remifemin was hugely popular esp as serious concerns were being raised about HRT.
I also remember similar concerns about soy milk which also supplied phytoestrogens.