Estrogen is a sex hormone that supports bone health in not only women but also in men. Estrogen is key during the growth spurt in puberty along with other hormones. For women after puberty, regular menstrual cycles are a general indicator of adequate estrogen support for the bone and other critical functions.
In the menopause transition, estrogen levels start waning then production ends with ovarian failure. A small amount of estrogen continues to be produced from the adrenal gland. Bone loss accelerates during the transition to menopause. A higher rate of bone loss continues in early menopause for an average five years. Then bone loss continues with aging at a slower rate.
Estrogen as Medicine
For postmenopausal women, estrogen is indicated for prevention of osteoporosis, not treatment. Estrogen is available by prescription in a variety of forms including tablets, patches, sprays, and creams.
Estrogen decreases the breakdown of bone. This form of therapy basically restores the balance between breakdown and formation to stabilize bone mass.
Safety concerns have limited the use of estrogen. All estrogen products have a black box warning on their labels warning of the risk of heart attack, stroke, clotting in deep veins in the legs, lungs, or eyes; endometrial and breast cancer; and memory problems. In addition, gallbladder disease, elevated blood pressure, abnormal liver function, and high triglycerides are possible. Other side effects include breakthrough bleeding, breast tenderness, ankle swelling, joint pain, and headache.
Low Dose Prevents Bone Loss
Estrogen used in low doses is effective in preventing bone loss. For example, one product called Menostar® that is a patch changed once a week is approved only for prevention of osteoporosis. The Menostar patch estradiol dose is 14 micrograms each day and each patch contains a total of 1 mg of estradiol. At the end of a two-year clinical trial showed about a 3% improvement at the lumbar spine and stable bone density at the hip.
Menostar product website