If you are ER+, have you been prescribed an aromatase inhibitor or tamoxifen? These will actually do the opposite of HRT, and will reduce levels of estradiol in the body below detectable levels. As an ER+ breast cancer survivor (so far) with a high ER score, I can say I would be very very cautious and avoid anything that will feed your cancer (or an errant cells). It's hard I know! Have you talked with your doctor?