Hormone therapy after hysterectomy/menopause is a way to replace the oestrogen you’ve lost, either with oestrogen and progestin or with oestrogen alone. Women who have had their uterus and ovaries removed typically receive only oestrogen replacement therapy (ERT). Women who have only had their ovaries removed, on the other hand, require both oestrogen and progestin. This is because oestrogen can raise the risk of uterine cancer on its own. This danger is eliminated when progestin is added.

Both ovaries are rarely, if ever, removed without the uterus. Only one ovary is frequently removed, obviating the necessity for HRT at the time of surgery.