Four Decades of the Birth Control Pill
"Like some of these targeted estrogen replacement therapies, they're trying to find drugs that interact with estrogen receptors that don't make people have headaches, don't make them gain weight, don't affect clotting," Roberts says.
"Maybe we want to catch just the ovum and not make it mature. Or make a minor change in the uterus so the ovum can't implant. Most of the research is on trying to refine them, to do just exactly what you want, like 'smart bombs.'"