I’m on tamoxifen and have high blood pressure, there was no noticeable difference in BP with the tamoxifen. I had labile hypertension before this all started, they like to call it “white coat” syndrome because I’m always high in the doctor’s office. That, I believe, is from low estrogen for some of us - which tracks with the problems you had on AIs.

I started on 20mg, but am now on 5 mg. I cut the pill. I won’t take 10 mg every other day - might work okay, but when trying to lower tamoxifen (before protocols changed to allow 5 mg a day) I was taking 10 mg every day and still had headaches, and I’m afraid the fluctuations of every other day will bring headaches back.

Tamoxifen doesn’t cut well - I’ve tried 3 different pill cutters. The pharmacy refuses to cut it. I now use a single edge razor blade, and put the pill on a small pile of paper, then cut. The blade is very sharp, and the softer surface of the paper seems to give enough so the pill doesn’t crumble as much. I don’t get it precisely in half, but no worries. In two days, I get the full amount, maybe a little less one day, maybe a little more the next. The half life of tamoxifen is 7 days, so there is always a quite high residual amount in my body.