The Associated Press:

Today, Plan B One-Step is sold behind pharmacy counters, and buyers must prove they're 17 or older to buy it without a prescription. Tuesday's decision by the Food and Drug Administration lowers the age limit and will allow the pill to sit on drugstore shelves next to spermicides or other women's health products and condoms — but anyone who wants to buy it must prove their age at the cash register.

Some contraceptive advocates called the move promising.

"This decision is a step in the right direction for increased access to a product that is a safe and effective method of preventing unintended pregnancies," said Sen. Patty Murray, D-Wash. "It's also a decision that moves us closer to these critical availability decisions being based on science, not politics."

The pills contain higher doses of regular contraceptives, and if taken within 72 hours of unprotected sex, can cut the chances of pregnancy by up to 89 percent. However, the morning after pill should not be confused with the "abortion pill," mifepristone (It was called RU-486 when it was being developed).