How Modafinil Promotes Wakefulness

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What Is Modafinil?

Modafinil is sometimes called a "wakefulness-promoting agent." This medication works to reduce sleepiness caused by conditions including narcolepsy, sleep apnea, and shift work sleep disorder.

It is available as a tablet taken by mouth, usually once a day. Most people who work during the day take the drug in the morning. However, shift workers who take the drug to promote wakefulness take the drug before their shifts begin.

This article discusses how modafinil works to promote wakefulness. It also explores the potential side effects of the medication and its potential for misuse.

How Modafinil Works

Modafinil, also known by its brand name Provigil, is a central nervous stimulant. Central nervous stimulants are substances that stimulate the brain. These medications impact the body by speeding up physical and mental processes.

Researchers believe that this drug works by affecting chemical messengers known as neurotransmitters.

Modafinil appears to make chemical messengers like monoamines, catecholamines, dopamine, serotonin, adenosine, and noradrenaline more available in the spaces between cells. Modafinil affects several parts of the brain, including the hypothalamus, hippocampus, and amygdala.

The result of these changes is reduced sleepiness. Because it is a mild stimulant, modafinil may produce less anxiety, irritability, and jitteriness than some other stimulants.

What Does Modafinil Treat?

Modafinil is used to treat problems with sleep, arousal, and wakefulness. Some conditions treated with modafinil include:

  • Depression
  • ADHD
  • Narcolepsy
  • Obstructive sleep apnea
  • Sedation due to medications
  • Shift-work sleep disorder
  • Traumatic brain injury


Modafinil has been approved by the U.S. Food and Drug Administration to treat daytime sleepiness in individuals who have conditions that include narcolepsy, shift work disorder, and sleepiness caused by medical conditions such as sleep apnea.

Potential for Misuse

Sometimes modafinil is misused. It is not uncommon for people to misuse cognitive-enhancing or psychostimulant drugs in order to increase productivity, combat fatigue, and help with intellectual challenges. 

The misuse of cognitive-enhancing drugs like amphetamine, methylphenidate, and modafinil is typically associated with university students. Some estimates suggest that 7% to 20% of U.S. college students have reported misusing the drugs.

However, it is not uncommon for other groups of people to misuse these drugs as well. For example, 8.9% of surgeons surveyed in Germany reported using cognitive-enhancing drugs without a prescription.

Modafinil is less addictive than other psychostimulants like amphetamine. However, some evidence suggests that dependence is still possible.

Modafinil Side Effects

Modafinil can also cause some serious side effects and should be taken only when prescribed by a healthcare provider. Common side effects of modafinil include agitation, anxiety, nausea, and vomiting.

Other potential side effects include:

  • Blisters
  • Chest pain
  • Constipation
  • Diarrhea
  • Difficulty breathing
  • Hallucination
  • Hives
  • Hoarseness
  • Insomnia
  • Irregular heartbeat
  • Rash
  • Suicidal ideation (thoughts of suicide)
  • Sweating

Some of these are serious and potentially dangerous. If you experience any of these side effects, contact your healthcare provider.

If you are having suicidal thoughts, contact the National Suicide Prevention Lifeline at 988 for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911.

For more mental health resources, see our National Helpline Database.

Some side effects, such as insomnia, restlessness, chest pain, nausea, and confusion, may result from an overdose of modafinil. If you suspect an overdose, call emergency services or contact a physician immediately.


Modafinil isn't for everyone, and before your physician prescribes you this medication, you should inform them if you:

  • Are allergic to modafinil or armodafinil (a similar drug)
  • Take antidepressant medications including SSRIs, TCAs, and benzodiazepines
  • Take antiseizure medications like phenytoin and carbamazepine
  • Take antifungal medications like itraconazole and ketoconazole
  • Use or are dependent on alcohol or other substances
  • Take any vitamins, nutritional supplements, or herbal supplements

People who have unstable angina or recently had a heart attack shouldn't be given modafinil. Furthermore, it's unclear the effect that modafinil has on the seizure threshold, or a person's likelihood to have a seizure. Because of this, modafinil should be used with caution in people with epilepsy and other seizure disorders.

There are no long-term studies on the effects of modafinil on the brain. A physician must carefully consider whether to prescribe modafinil and weigh the benefit of its stimulant properties with potential side effects.

It is important to understand that if your healthcare provider has prescribed modafinil, this decision was based on your specific needs and characteristics. You should only take modafinil if it has been prescribed to you by a physician or other healthcare professional. 

A Word From Verywell

Modafinil can be effective for promoting wakefulness when taken as prescribed. Follow your healthcare provider's instructions. Do not take your medication in a larger dose, more frequently, or for a longer period of time than you have been instructed to do by your prescriber.

This medication should also not be used as a substitute for adequate sleep. Continue maintaining good sleep habits and get enough rest at night while you are taking this medication. If you are still struggling to maintain wakefulness even when taking modafinil, talk to your doctor about your symptoms and treatment options.

5 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Food and Drug Administration. Highlights of prescribing information: Provigil.

  2. Easow Mathew M, Biswas T, Fahad S, Patnaik M. Modafinil for excessive daytime sleepinessCochrane Database Syst Rev. 2013;(11). doi:10.1002/14651858.CD010843/full

  3. Ram SS, Hussainy S, Henning M, Jensen M, Russell B. Prevalence of cognitive enhancer use among New Zealand tertiary students. Drug Alcohol Rev. 2016;35(3):345-51. doi:10.1111/dar.12294

  4. Franke AG, Bagusat C, Dietz P, et al. Use of illicit and prescription drugs for cognitive or mood enhancement among surgeonsBMC Med. 2013;11:102. doi:10.1186/1741-7015-11-102

  5. Kim D. Practical use and risk of modafinil, a novel waking drugEnviron Health Toxicol. 2012;27:e2012007. doi:10.5620/eht.2012.27.e2012007

By Naveed Saleh, MD, MS
Naveed Saleh, MD, MS, is a medical writer and editor covering new treatments and trending health news.