The morning-after pill known as Plan B is steeped in controversy again. The Department of Health and Human Services has taken the rare step of overruling the Food and Drug Administration and its science advisors and will not allow the pill to be sold over the counter in drugstores unless a woman can prove she is older than 17. 

The stunning override of the FDA is bad public policy.  This is a case of politics triumphing over science yet again when it comes to matters of reproduction, contraception and abortion in the U.S.

Plan B has stirred strong emotions from the minute its manufacturer sought FDA approval. During the Bush administration, abortion foes tried to stifle the drug on the grounds that it works as an abortion agent even though the drug actually prevents a fertilized egg from implanting in the womb, which is not in the scientific sense of the term an abortion. Some docs and pharmacists made headlines by saying they would not prescribe the pill even in the case of a rape.  Some hospitals will not stock it.

Plan B won't be available OTC for younger teens

But the pill has been shown safe time and time again. The FDA panel that approved it for over-the-counter use simply could not find any scientific reason to worry about its safety. The benefits of preventing unwanted pregnancies and the risks of surgical abortions are significant.

So why not let any woman, even a girl of 14 or 15, have access?  Because, politically at least, saying a young girl can protect herself against an unwanted pregnancy is not the most popular stance to take.

The fact is that many teen girls have sex – and many will not talk about it with their parents.

Sometimes that sex is coerced or forced. Sometimes it is a relative or friend who is the exploiter.

These are not scenarios that we like to admit to. But they are real. That's why the pills should be readily available on drugstore shelves, but include an insert listing resources where young girls can get help.

Making Plan B hard to get doesn't protect these young girls. It puts them in an even worse spot.

Read more columns by Art Caplan:

Shame on school for rejecting boy with HIV

Vatican push for adult stem cells can't ignore good science

Art Caplan, Ph.D., is the director for the Center for Bioethics at the University of Pennsylvania.  Follow him on Twitter @ArthurCaplan.