It goes up particularly after she passes menopause, presumably because that is when she loses the protective effect of natural estrogen.

Hysterectomy is considered a last resort after failure of treatments that suppress natural estrogen or, if possible, conservative surgery to remove the excess tissue.

Butylparaben is estrogenic, meaning it mimics natural estrogen in the body.

That would prevent a woman's own natural estrogen from binding there.

Both are chemically different from natural estrogen, which could not be taken as a pill because it is broken down by the digestive tract.

These compounds compete with natural estrogen for a docking site on cells throughout the body.

The study will try to determine whether hormone drugs take the place of natural estrogen in protecting the hearts of older women.

Phytoestrogens are much less powerful than pharmaceutical or natural estrogen, and they enter the cells through a different receptor.

These substances act as weak estrogens and block the action of natural estrogen in some tissues.

The loss of natural estrogen as women age may contribute to the higher risks of heart disease seen after menopause.