Women who take sleeping pills have been inadvertently double-dosing, according to a new announcement from the Federal Drug Administration. Today FDA regulators told the makers of sleep-aid prescriptions such as Ambien, Zolpimist, and Edluar to cut recommended doses for women in half. The order comes after new findings about the different ways men and women respond to zolpidem, the active ingredient in most sleeping pills. 

Women eliminate zolpidem from their bodies slower than men. By studying people eight hours after they took sleeping pills, FDA researchers found that 10 to 15 percent of women still had   enough zolpidem coursing through their bloodstreams to impair driving. Only three percent of men exhibited the same prolonged wooziness. That's why recommended doses of Ambien will soon go from 10 milligrams to 5 milligrams for women. FDA Center for Drug Evaluation and Research deputy director Robert Temple told The New York Times's Sabrina Tavernise: 

Most people thought that by the morning it is gone. What we’re reminding people is that is sort of true, but that in some women who take a full 10 milligram dose, and in a lot of people who take the control release dose, it is not entirely true. Some people will be impaired in the morning.

The news that women may have been taking too much sleeping medication without even knowing it is kind of freaky, since too much Ambien can make people do things in their sleep they won't remember later—things like "driving, or preparing and eating food," according to Mayo Clinic sleep specialist Eric Olson.