They want complete medical history.
I don't believe HRT is an issue at all, and I don't think there are any interactions from T suppression with commonly used medications in dentistry.
From what I know, dentists will want to know if you are on anything that alters blood clotting (warfarin, aspirin etc), blood pressure, and bone metabolism (drugs for osteoporosis) if you are going to be having surgery in your mouth.