The use of noncontraceptive estrogens declined after evidence was published that they increase the risk of endometrial cancer. Nonetheless, they are still used commonly and for long periods, especially by hysterectomized women. Use of the drugs has increased recently, perhaps because the drugs have been recommended as prophylaxis against osteoporosis. The drugs are also being promoted for use in conjunction with a progestin, because it is thought that the combination may protect against endometrial cancer. Little is known about the effects of these drug regimens on myocardial infarction risk, and some progestins (in particular the 19-norprogestins) are thought to influence lipid profiles unfavorably. Insofar as myocardial infarction is a major cause of morbidity and mortality in women beyond age 49, an effect of these drugs, either beneficial or adverse, on myocardial infarction risk is of considerable public health importance.