The birth control pill has been called the most important scientific advance of the 20th century, and no wonder. Fifty years after its approval by the Food and Drug Administration, it is still one of the leading methods of contraception, in the United States and around the world.

Much has been written about how it revolutionized sexual and social relationships, allowing women to defer pregnancy, enter the work force and make life choices their mothers could not — or, if you prefer, spawning promiscuity and undermining the foundations of marriage.

But the pill also led to profound changes in the F.D.A. itself — a revolution in what Dr. Margaret Hamburg, the current food and drug commissioner, calls regulatory science. Many of the steps that underlie modern drug approvals — extensive clinical trials, routine referrals to panels of outside experts, continuing assessments of a medicine’s safety, and direct communications between the F.D.A. and patients — were pioneered to deal with evolving concerns about the pill’s safety.

In regulatory terms, the pill brought about a kind of reformation: just as Martin Luther insisted that individual Christians could communicate directly with God without the mediation of priests, the pill eventually led the F.D.A. to communicate directly with patients without going through doctors.