Go Pills Air Force: What They Are, What's In Them and Who Authorizes Them
The go pills air force crews carry are prescription stimulants: dextroamphetamine and modafinil.3 Flight surgeons may prescribe them to counter aircrew fatigue when commanders authorize it,4 and only flight surgeons dispense them.3 In November 2012, modafinil was the only Air Force-approved go pill;2 a 2025 congressional research report lists both.4
Personal account, not medical advice. Modafinil is a prescription medicine, and a Schedule IV controlled substance in the United States. Nothing here is a recommendation to start, stop or change anything. Talk to a doctor.
What go pills are, and who can issue them
Wikipedia's article on go and no-go pills says the terms refer to medications meant "to increase wakefulness or to induce sleepiness in order to ensure adequate alertness or rest in preparation for upcoming tasks".1 A go pill is "a wakefulness-promoting agent used for fatigue management, especially in a military combat-readiness context".1
The go pills military aircrews carry are prescription stimulants: the OPSS page on stimulants for flight crew alertness calls them "prescription medications (dextroamphetamine or modafinil)", so they "can only be dispensed by a flight surgeon", and says the use of go pills, and of the ground test that goes with them, "is optional".3 Which go pill is approved can also depend, in some cases, on the aircraft type, and the controls on dextroamphetamine are generally stricter than those on modafinil.3
For go pills for pilots, the Congressional Research Service (CRS) overview of sleep and fatigue in military aviation sets out the chain of authority: "A flight surgeon may prescribe stimulants, commonly called go-pills, when authorized by a unit commander to counter aviator fatigue and improve alertness and performance."4 The same overview says the services limit pharmacological measures to specific operational circumstances and run authorization through medical and command channels, and that in all services the use of these measures is voluntary.4
From amphetamine to modafinil: why the switch
Amphetamine came first. Wikipedia's article records that methamphetamine was used historically, such as during the Second World War, and that amphetamine is "no longer approved officially for use by the U.S. Air Force".1
The 2004 Air Force news article gives the timeline in its own words: "For more than 60 years, dextroamphetamine was the Air Force's 'go pill' of choice. In December, a new compound, modafinil, was approved for some bomber missions."5
The aeromedical reason comes from the researchers. Dextroamphetamine is authorized for use by the aircrews of all U.S. military services, the 2012 helicopter study notes, but "its potential for abuse and subsequent addiction is of aeromedical concern", and the authors wanted an alternative stimulant "that displays a low affinity for dopamine uptake binding sites".6
The study records that the U.S. Air Force authorized modafinil military use for certain missions in 2003, including dual-pilot bomber missions longer than 12 hours, extended in 2006 to single-seat fighter operations.6
Wikipedia's list of psychoactive drugs used by militaries records where that left things: "As of November 2012, modafinil is the only drug approved by the Air Force as a 'go pill' for fatigue management", and the use of dextroamphetamine is no longer approved.2 The 2025 position reads differently: the CRS overview updated on 13 May 2025 still lists modafinil for the Air Force alongside dextroamphetamine for all services.4
What the military trials found
The first trial is Caldwell and colleagues' 2004 study of F-117 pilots. It used a "quasi-experimental, single-blind, counterbalanced design" and tested modafinil in 10 Air Force F-117 pilots during 37 hours of continuous wakefulness, with 100 mg given after 17, 22 and 27 hours without sleep.8 The results: modafinil "attenuated flight performance decrements on six of eight simulator maneuvers", and the study reports that it "maintained flight accuracy within approximately 15-30% of baseline levels, whereas performance under the no-treatment/placebo condition declined by as much as 60-100%", with benefits "most noticeable after 24 to 32 h of continuous wakefulness".8
The study records a caution. At least at that dose, the drug's effects "were not subjectively salient", and personnel "should be cautioned regarding this particular drug characteristic".8 The authors' own conclusion is narrower: "Although modafinil did not sustain performance at predeprivation levels, the present study suggests that modafinil should be considered for the military's armament of short-term fatigue countermeasures."8
The Air Force's own news article reports the same findings plainly: while the pilots were on the medication their performance "significantly improved", especially after 25 hours without sleep, and during the simulator tests modafinil "significantly" reduced the effects of fatigue during flight maneuvers.5 The limit came with it: aircrew members "did not entirely maintain performance at fully rested levels", and the comparison to dextroamphetamine stayed provisional: "Until more research is done, scientists said modafinil should be viewed as an option to, but not as a replacement for, dextroamphetamine."5
The second trial is Estrada and colleagues' 2012 military helicopter study. Eighteen UH-60 Black Hawk helicopter aviators each completed 15 flights during two 40-hour periods of sustained wakefulness, and the study gave three doses at 4-hour intervals of modafinil (100 mg), dextroamphetamine (5 mg) or placebo, with each aviator receiving two of the three conditions.6 Twelve of the 15 data-collection flights were flown in an actual helicopter.6 Its results, in the authors' words, "showed that modafinil, like dextroamphetamine, maintained alertness, feelings of well-being, cognitive function, judgment, risk perception, and situation awareness of sleep-deprived aviators consistently better than placebo and without side effects of aeromedical concern".6
The same paper is candid about what it did not show: the authors write that the lack of significant drug effects for flight performance may have been due to the relatively short duration of the flights.6 Recovery sleep differed as well: the placebo group slept an average of 15 minutes longer than the modafinil group, with greater sleep efficiency.6
A 2004 editorial in the same journal addressed fatigue and go/no-go pill use in extraordinarily long combat sorties.12
Ground tests, last resort and no-go pills
OPSS describes the ground test as a requirement for each individual who will use them, with flight surgeon supervision, "sufficiently in advance of need, to determine individual tolerance and dosing", followed by "a specified period of non-flight status".3
The services recommend caffeine over go pills, and reserve go pills for situations when "all other fatigue countermeasures have been exhausted or have been determined inadequate for the immediate situation".3 The CRS overview puts the same order in place: flight surgeons may prescribe approved agents as a fatigue management measure "when administrative and behavioral measures are known or expected to be insufficient".4
Across the aisle sit the no-go pills. Wikipedia's article lists the drugs approved as no-go pills by the U.S. Air Force for aircrew and AFSOC forces as of November 2012: temazepam, zaleplon and zolpidem, with restrictions on subsequent flight operations of 12, 4 and 6 hours respectively.1 The CRS overview describes sedative-hypnotics a flight surgeon may prescribe for limited periods when authorized by a unit commander to aid sleep initiation where an operational need exists, and records the Department of Defense's caution that these have a "wide range of side effects" that can affect readiness.4
Civilian aviation differs: the CRS overview states that Federal Aviation Administration (FAA) regulations do not permit the use of stimulants, while FAA-certified medical examiners may authorize sedative-hypnotics and melatonin supplements for occasional or limited use by civilian pilots.4
Pilots versus air traffic controllers
Can pilots take modafinil? Military rules for pilots differ by service and, in some cases, by aircraft type.3 As of its 2020 update, OPSS recorded that Navy policy preferred modafinil over dextroamphetamine, and that the Army had not yet approved it.3 Estrada describes Air Force authorization for certain missions in 2003 and for single-seat fighter operations in 2006.6 OPSS's 2020 account says the Air Force's approved medications list covered modafinil for all flight crew with a few exceptions.3
For U.S. air traffic controllers, the FAA's controller drug guidelines list modafinil as unacceptable.9 The therapeutic drug guidelines for air traffic control specialists (ATCS), tied to the September 1998 agreement between the National Air Traffic Controllers Association (NATCA) and the FAA and hosted by Leftseat, list modafinil among stimulants that are "not acceptable", and the same document says it "shall not be used by any ATCS as authority or permission for use of any medication while performing ATCS duties".9
Research involving air traffic control students exists, and it is research rather than practice. Phillips and colleagues ran a randomized controlled trial in 48 U.S. Naval air traffic control students, giving a 150 mg dose of armodafinil or a placebo, then testing psychomotor vigilance 8 to 11 hours after the dose.10 The armodafinil group showed "significantly fewer lapses of attention compared to the control group", and the authors concluded that the results "justify additional investigation into the efficacy of armodafinil to promote sustained vigilance in military operational settings".10
Alongside it is a study of air force crewmembers, not controllers. Wingelaar-Jagt and colleagues tested 200 mg of modafinil against 300 mg of caffeine and a placebo in 32 Royal Netherlands Air Force volunteers after a median 17 hours awake, and reported "statistically significant effects of caffeine and modafinil compared with placebo on all endpoints, except for VigTrack mean tracking error", with modafinil "effective for longer than caffeine, which is consistent with its longer half-life".11 The paper's title describes air force crewmembers rather than controllers, and the authors are clear about the setting: the study "was performed in a controlled laboratory environment and used relatively simple tasks", so its findings "should be carefully extrapolated to real-life scenarios".11
The civilian view: what long-term use adds
None of the flying above is mine; I never served in the military. What more than a decade of ordinary use adds is a distinction the helicopter study also ran into: alertness held up on the drugs, while flight performance showed no significant drug effect.6
In my own experience, the two split apart. Once, after taking far too much, I was wide awake and useless. On another stretch of daily use, I looked busy while getting little done. In both cases, being awake and getting work done had come apart.
The 2004 study recorded a related concern: personnel might escalate the dose without flight surgeon approval because they could not feel the drug working.8 The military system surrounds the pill with a ground test, a commander's authorization and monitoring by flight surgeons.34 My own early dose-finding was the opposite of a ground test: too much, too often, at odd intervals. A ground test exists to catch exactly that.
Last resort is the other half of the design. My own practice narrowed in the same direction over the years, to only when a specific task justified it, and never after a poor night's sleep. That is a description of what I did, not a rule for anyone else.
The BBC's 2024 feature puts the same limit in one line. Wingelaar-Jagt, a coauthor of the Dutch trial, tells the BBC: "It's a countermeasure against fatigue, but it does not take away the fatigue itself."7
Written by The Night Owl, a long-term user of modafinil who is not a doctor, pharmacist or healthcare provider. This page describes one person's experience alongside published research. It is not medical advice.
Sources
1: Wikipedia. Go and no-go pills. Accessed 25 September 2026. https://en.wikipedia.org/wiki/Go_and_no-go_pills
2: Wikipedia. List of psychoactive drugs used by militaries. Accessed 25 September 2026. https://en.wikipedia.org/wiki/List_of_psychoactive_drugs_used_by_militaries
3: OPSS. Stimulants for Flight Crew Alertness. Updated 6 May 2020. https://www.opss.org/article/stimulants-flight-crew-alertness
4: Congressional Research Service. Management of Sleep and Fatigue in Military Aviation (IF11881, version 5, updated 13 May 2025). https://www.congress.gov/crs-product/IF11881
5: Woodring, J.C. (Tech. Sgt., U.S. Air Force). Air Force scientists battle aviator fatigue. Air Force Print News, 30 April 2004. https://www.af.mil/News/Article-Display/Article/137025/air-force-scientists-battle-aviator-fatigue/
6: Estrada, A., Kelley, A.M., Webb, C.M., Athy, J.R. and Crowley, J.S. Modafinil as a replacement for dextroamphetamine for sustaining alertness in military helicopter pilots. Aviation, Space, and Environmental Medicine, 2012. https://gwern.net/doc/modafinil/2012-estrada.pdf
7: Gorvett, Z. The drug pilots take to stay awake. BBC Future, 14 March 2024. https://www.bbc.com/future/article/20240314-the-drug-pilots-take-to-stay-awake
8: Caldwell, J.A., Caldwell, J.L., Smith, J.K. and Brown, D.L. Modafinil's effects on simulator performance and mood in pilots during 37 h without sleep. Aviation, Space, and Environmental Medicine, 2004. https://pubmed.ncbi.nlm.nih.gov/15460629/
9: Leftseat. Therapeutic Drug Guidelines for Air Traffic Control Specialists (guidelines tied to the September 1998 agreement between the National Air Traffic Controllers Association and the Federal Aviation Administration; document offered in fulfillment of that agreement's Medical Qualifications article). Accessed 25 September 2026. https://www.leftseat.com/air-traffic-controller-specialists-atcs-2/
10: Phillips, J.B., Simmons, R.G. and Arnold, R.D. A single dose of armodafinil significantly promotes vigilance 11 hours post-dose. Military Medicine, 2011. https://pubmed.ncbi.nlm.nih.gov/22128728/
11: Wingelaar-Jagt, Y.Q., Bottenheft, C., et al. Effects of modafinil and caffeine on night-time vigilance of air force crewmembers: A randomized controlled trial. Journal of Psychopharmacology, 2022. https://pmc.ncbi.nlm.nih.gov/articles/PMC9912306/
12: Schultz, D. and Miller, J.C. Fatigue and use of go/no-go pills in extraordinarily long combat sorties. Aviation, Space, and Environmental Medicine, 2004. https://pubmed.ncbi.nlm.nih.gov/15086130/