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Nootropics

Modafinil

A prescription wakefulness medicine with only a very small average cognitive effect in rested healthy adults and important medical, interaction, and sporting constraints.

Emerging
Evidence rating
Evidence review

What the evidence says

Modafinil is approved to improve wakefulness in narcolepsy, obstructive sleep apnea, and shift-work disorder. Cognitive enhancement in a rested healthy person is not an approved use and should not be confused with treating pathological sleepiness.[6]

A 2019 meta-analysis of 19 placebo-controlled single-dose trials found a statistically significant but very small overall cognitive effect in non-sleep-deprived adults: Hedges' g 0.10. It found no meaningful difference between attention, executive function, memory, or processing speed.[1]

An earlier systematic review sounded more favorable for complex tasks, but only about half of studies improved attention or learning and memory, and divergent creativity sometimes worsened. Methodological differences and selective tasks make isolated positive findings a poor guide to real-world benefit.[2]

Individual trials reinforce the limited average effect. A large student crossover study found no global cognitive improvement beyond one low-demand Stroop condition, while a middle-aged-adult trial found few benefits and more errors on a set-shifting task. Earlier small studies reported selected improvements rather than a universal enhancement.[4][5][3]

The label warns about headache, nausea, anxiety, insomnia, rare serious rash, psychiatric reactions, cardiovascular caution, and reduced effectiveness of steroidal contraception during treatment and for one month afterward. Modafinil is Schedule IV in the United States and prohibited in competition by WADA.[6][7]

Potential benefits

  • Improves wakefulness for its approved sleep-related indications under medical care.[6]
  • May produce small acute improvements on selected cognitive tasks in rested adults.[1]

Side effects and cautions

  • Headache, nausea, anxiety, nervousness, and insomnia are common; serious skin or psychiatric reactions require prompt medical assessment.[6]
  • It can interact with medicines, reduce steroidal-contraceptive effectiveness, and create anti-doping consequences.[6][7]
How we scored it

Evidence breakdown

Controlled studies support wakefulness in approved sleep disorders, but healthy-user enhancement trials are acute, inconsistent, and show little average benefit.

Clinical relevanceLow

Healthy-user studies rely on short laboratory tasks rather than learning, work, or health outcomes.

Study qualityModerate

Placebo-controlled trials and meta-analyses exist, but studies are small and heterogeneous.

Safety dataHigh

Prescription labeling documents common reactions, serious warnings, and interactions.

References

Full source list

  1. The Efficacy of Modafinil as a Cognitive Enhancer: A Systematic Review and Meta-Analysis

    Journal of Clinical Psychopharmacology · 2019

  2. Modafinil for cognitive neuroenhancement in healthy non-sleep-deprived subjects: A systematic review

    European Neuropsychopharmacology · 2015

  3. Cognitive enhancing effects of modafinil in healthy volunteers

    Psychopharmacology · 2002

  4. Effects of modafinil on attention performance, short-term memory and executive function in university students

    Medwave · 2015

  5. The cognitive-enhancing properties of modafinil are limited in non-sleep-deprived middle-aged volunteers

    Pharmacology, Biochemistry and Behavior · 2004

  6. Provigil (modafinil) prescribing information

    DailyMed, U.S. National Library of Medicine · 2022

  7. 2026 List of Prohibited Substances and Methods

    World Anti-Doping Agency · 2026