Estrogen therapy during pregnancy has been associated with an increased risk of birth defects, such as defects in the reproductive organs. Breast-feeding mothers shouldn't take estrogen because it passes into the breast milk, and its effect on infants is unknown. Estrogens may alter the effect of some other drugs, including drugs to prevent blood clots, diabetes drugs, calcium supplements, and a breast cancer drug called tamoxifen. Humidity from steamy baths and showers make the bathroom medicine cabinet a poor place to store drugs. Keep estrogens out of the reach of children.
Discard estrogens when they're no longer needed or when the expiration date is past.