It has long been appreciated that bone loss rapidly accelerates at onset of menopause. This rate of loss is reduced when physiologic doses of hormones are taken systemically. Menopausal hormone therapy (MHT), previously referred to as hormone replacement therapy (HRT), includes estrogen with or without progesterone.
Prior to publication of the Women's Health Initiative (WHI), a prospective, primary prevention trial, HRT was commonly used for osteoporosis prevention (and other things). WHI showed that risks of stroke, MI, DVT, breast cancer exceeded possible benefits such as reduced osteoporotic fractures. HRT is therefore used primarily for osteoporosis prevention and treatment only when benefit outweighs risk (such as in patients with severe osteoporosis who are unable to take other therapies or who have severe menopausal symptoms, especially early in menopause).
Conjugated equine estrogen (Premarin) 0.625mg po daily
Estradiol (Estrace) 1 - 2mg PO daily
Estradiol (Vivelle) 0.05mg daily transdermally
Progesterone in the form of medoxyprogesterone acetate (Provera) 2.5mg PO daily or micronized progesterone 200 mg PO daily, is added when a women has her uterus (to reduce the risk of endometrial hyperplasia).