@part I cut a 10 mg tamoxifen pill in half. I use the terms “cutting” and “in half” loosely. Those pills are not designed to be cut, the pill is not packed tight and it crumbles easily. I’ve tried 3 different pill cutters. The pharmacy refuses to cut the pills - my guess is because they know it will crumble.
I have found some success using a single edge razor blade with the pill on a padded surface.

I had started with the 20 mg and could not tolerate it. So I had extra 20s when they switched me to 5mg. For a while I cut the 20s into quasi 1/4s and used the best pieces from that.

I am now using the 10mg cut in half-ish. I’m okay with taking a little more one day, and the other “half” the next day. That is no different than the method they say I can do, which is a 10 mg every other day. But the cut pill does have a crumbly edge and loses small pieces when storing it. I’m kind of okay with the idea that I may only be taking about 4.5 mg but I may not be getting enough everyday to meet that endoxifen concentration that is therapeutic and needed to block the estrogen receptors.

I do not want to take 10 mg every other day as it could potentially bring back the worst of the side effects I was having on that dose. (When I couldn’t tolerate the 20 mg, I reduced my dose myself to 10 mg everyday to see if it helped. It did not.)

More info, maybe helpful?!? I was 69 when I started tamoxifen. A few side effects within the first couple of weeks. It took 3 months to fully feel the effects of the drug. I never had full blown hot flashes, only poor thermal regulation. If I did over-heat from a hot car or exercise it took an uncomfortable amount of time to finally cool down. Some mood swings. Genitourinary syndrome of menopause disappeared (yea!) No body aches/pains. After 3 months on 20mg I developed headaches 24/7. No cause could be found. A brain MRI was done, nothing extraordinary (haha). It was decided it was the tamoxifen. On 5 mg headaches went away.