The Effect of Estrogen & Progesterone on Bones

Progesterone and estrogen have a profound impact on bones. The loss of both hormones because of perimenopause, menopause, hysterectomy or cancer treatments can lead to weak or brittle bones. Decreased bone density can make the hip, wrist and spine especially susceptible to fractures and place women at risk for osteoporosis.

Bone Function of Estrogen

• Estrogen is a hormone produced in the ovaries that plays a critical role in maintaining healthy bone and delaying bone loss. Estrogen helps the bones absorb and conserve calcium, which in turns makes them strong.

Bone Function of Progesterone

• Progesterone is a hormone made in the ovaries and adrenal glands, and it is vital to the formation of osteoblasts, which are bone-building cells. Human bones break down with normal wear and must rebuild themselves; osteoblasts help to strengthen and replace damaged areas with new bone.

Decreased Estrogen and Bone Health

• Decreased estrogen can lead to bone loss and eventually osteoporosis. If a woman's ovaries are not producing adequate estrogen because of natural causes or medical treatments, the rate of bone loss speeds up as the amount of estrogen drops, because the bones are not absorbing calcium effectively.

Decreased Progesterone and Bone Health

• Because progesterone is necessary for bone formation, a decrease in progesterone can cause a decrease in osteoblasts, which are needed to rebuild bones. This means that bones eventually become weak and brittle, because they are not being rebuilt effectively.

Combined Role of Estrogen and Progesterone

• Estrogen and progesterone must be in balance in order to build and maintain bones. Prior to menopause, progesterone levels tend to decrease in women. This can lead to an imbalance (a "surplus") of estrogen, which can cause various health problems. As a result, both natural and synthetic forms of estrogen and/or progesterone are available as a treatment for menopausal women.