Yeah ahem'
Well breast cancer risk. Plus I use to use estrogens cream along with anti androgens. It really calm the shedding down, but I swallow like a balloon and I am having a lot of trouble losing this weight. I think it is water. Anyway. Never use estrogens massively IMO.
It works great for transgenders. Again, the research is not definitive. You can't say there is a risk. There may be a risk. There may be a risk to anything though. I just got done dermarolling, and covered my head in Estriol afterwards. I'm only using it once a week because I don't want to be a woman, but if I was a woman I'd take the minimal risk of using it every day for a few months.