In January 2013, the Food and Drug Administration made a safety announcement regarding the insomnia drug zolpidem. In the announcement, they warned drug manufacturers that the recommended dose of zolpidem should be halved for women. The warning came after researchers performed pharmacokinetic trials with 250 women and 250 men. The trials found that 15% of the women and 3% of the men who had taken the recommended dose of zolpidem still had enough drug in their blood 8 hours later to cause impairment. STATE: Is there evidence that women are more likely than men to have impairing zolpidem levels 8 hours after dosing?