Regardless where you come down on the issue of contraception and availability of the new Plan B “morning after” pill, the Food and Drug Administration’s handing of Plan B provides ample evidence against expanded regulation of the pharmaceutical industry.

Plan B, an emergency contraction drug, was approved for sale by prescription in 1999 “indicated to prevent pregnancy following unprotected intercourse, a known or suspected contraceptive failure, or in cases of sexual assault.” When taken within 72 hours of unprotected intercourse, it reduces the chance of pregnancy by 84 percent. Plan B is not RU-486, the so-called abortion pill. It doesn’t not work if the woman is already pregnant, although reportedly it sometimes prevents a fertilized egg from implanting in the uterus.

Because Plan B is more effective the sooner it is taken, an FDA advisory panel voted overwhelmingly to recommend the drug for sale over the counter (OTC). Concerned that women under 16 may not understand the label instructions, the FDA rejected the committee’s recommendation.

To accommodate the FDA’s concerns, the drug’s maker, Barr Pharmaceuticals (NYSE: BRL), asked the FDA to allow OTC access to Plan B for women age 16 and older. A prescription would still be required for those 15 and younger. For many, that seemed like a reasonable approach, although of course it wouldn’t satisfy radicals on the Left or the Right. Now, contrary to the statutes governing the FDA and the FDA’s own rules, the matter is again on hold.

Plan B is a political football to be sure and the FDA Commissioner, Lester M. Crawford, is in a tough spot. Any discussion of contraception ” particularly an entirely new method designed to help reduce the chance of a pregnancy after intercourse ” brings out both sides, particularly the Far Left and the Far Right.

However, the FDA’s job is not to make the nation’s social policy or, for that matter, the nation’s health policy. Its sole job ” and therefore sole authority ” is to determine whether Plan B is safe and effective. It already made that decision in the affirmative. Federal law ” and the FDA commissioner’s promises to Congress ” dictates that Barr’s request for OTC status be approved. If elected lawmakers are concerned about women’s or girls’ access to contraceptives (either because they see it as too restrictive or too loose), then they are free to debate it to their heart’s content and the rest of us can watch them on C-SPAN. However, the FDA is an administrative agency charged with a specific scientific mission.

The FDA’s mishandling of Plan B does have a positive aspect. It provides an excellent case study in why we must guard against over regulation of health care, whether of pharmaceuticals or medical services. Just as it’s important to make sure our courts not legislate, it’s also important that executive branch agencies stick to their knitting.

With the new Medicare drug benefit, the federal government will soon become the world’s largest buyer of prescription drugs. Taxpayer-funded programs ” notably Medicaid and Medicare ” already account for just under half of the nation’s health spending. With more and more medical dollars in the hands of the government (gulp), lawmakers will be overcome with an urge to legislate and regulate. We must guard against this terribly perverse, inherently counterproductive instinct.

With so much public money in the mix, it is not realistic to assume a complete separation of science and politics. But that’s why we have a system of laws, due process, transparent decision-making, and limited, precise delegation of authority. The situation of Plan B and the FDA shows how this can quickly brake down if we are not watching.