Bioidentical hormones have the same chemical structure as hormones produced in the human body. There have been many studies demonstrating their safety. At this time, with the ready availability of bioidentical hormones, there is no reason to use non-human formulations. There is a track record of benefit and safety for women taking controlled doses of these hormones, in carefully selected formulations, under medical supervision. Horse hormones and progestins for hormone replacement should become obsolete. Patient demand will make this happen.