With the long-awaited approval of the abortion pill mifepristone in the US, scientists are hoping that the climate of public opinion will now be more amenable to studying its other medical properties.

As far back as 1993, a panel of the National Academy of Science's Institute of Medicine called for extensive studies of the drug for other health benefits. However, the ardent antagonism generated by abortion foes meant that the drug was too tightly controlled, until now, to permit additional studies.

“[The drug] has tremendous potential,” says Eric Schaff, professor of family medicine at the University of Rochester, who has studied its effect against uterine fibroid tumors, a condition affecting one-third of all women older than 40 and a leading cause of hysterectomies.

Other researchers who have examined the drug in small-scale trials have been encouraged by its potential against meningiomas of the brain and spinal cord and certain breast, ovarian and prostate cancers.

The drug is also effective in Cushing syndrome, which results from overproduction of the hormone cortisol—mifespristone binds to glucocorticoid receptors and prevents the cortisol from binding. “I also think it has tremendous potential as a once-a-week or once-a-month contraceptive, and as a drug to induce labor,” says Schaff.

At present, 37 patients are receiving the drug 'off-label' for conditions other than abortion, under the Food and Drug Administration's “compassionate use” program.