The oral contraceptive so universally embraced it became known simply as “the pill” was a decades-long dream of family-planning advocate Margaret Sanger, although none of the men who realized her vision started out with that purpose. In the 1930s scientists began discovering the roles of steroid hormones in the body and contemplated their therapeutic potential, but extracting hormones from animals was prohibitively expensive for most medical uses. Then, in 1939, Penn State chemist Russell Marker devised a method for making steroids from plants that remains the basis of hormone production even today. The company he founded, Syntex, soon developed an injectable synthetic progesterone derived from a wild yam.

Progesterone was an attractive drug candidate for treating menstrual irregularities that contributed to infertility because its natural role is to prevent ovulation during pregnancy and parts of a woman’s menstrual cycle. In 1951 Syntex chemist Carl Djerassi—who would later become famous for his prodigious literary output—synthesized a plant-derived progestin that could be taken in convenient oral form.

When Sanger and her wealthy benefactor, Katharine Dexter McCormick, approached steroid researcher Gregory Pincus about creating a contraceptive pill in 1953, he was working for the small and struggling Worcester Foundation for Experimental Biology in Massachusetts. But 20 years earlier at Harvard University, Pincus had scandalized polite society by carrying out successful in vitro fertilization of rabbits; Sanger believed he had the daring and know-how to produce her long-sought pill.

Pincus in turn recruited an infertility doctor, John Rock, who was already using progesterone to suspend his patients’ ovulation for a few months in the hope that their fertility would rebound. Still under the guise of fertility research, Rock and Pincus conducted their first human trial in 1954, injecting 50 women with synthetic progestins over the course of three months. All 50 stopped ovulating for the duration of the trial and resumed when the drugs were withdrawn. After several more years of experimentation, the first contraceptive pill was approved by the U.S. Food and Drug Administration in June 1960.