Go and no-go pills

In the U.S. military, no-go pill's (and their opposite go-pills) refers to a hypnotic medication taken to ensure adequate rest in preparation for upcoming tasks or for rest and recovery, or to a stimulant medication meant to increase wakefulness. As of November 2012, medications approved as no-go pills by the U.S. Air Force for Special Operations include:

• Temazepam (Restoril), with a 12-hour restriction on subsequent flight operation
• Zaleplon (Sonata), with a 4-hour restriction on subsequent flight operation
• Zolpidem (Ambien), with a 6-hour restriction on subsequent flight operation

Go pill

In contrast to the sleeping agents, a go pill refers to a wakefulness-promoting agent used for fatigue management, especially in a military combat-readiness context; this is contrasted with a no-go pill, which is used to promote sleep in support of combat operations. A go pill generally contains one of the following drugs:

• Amphetamine (methamphetamine having been used historically, such as during the Second World War), which is a strong psychostimulant drug; no longer approved officially for use by the U.S. Air Force, possibly due to safety concerns brought up in the wake of incidents like the Tarnak Farm incident.
• Modafinil, a wakefulness-promoting drug (or eugeroic)

The U.S. Air Force uses dextroamphetamine as one of its "go pills", given to pilots on long missions to help them remain focused and alert. Conversely, "no-go pills" are used after the mission is completed, to combat the effects of the mission and "go-pills".