Pharmaceutical

Modafinil

2-[(Diphenylmethyl)sulfinyl]acetamide

Evidence TierAWADA PROHIBITED

tuneTypical Dose

100–200 mg per day

watchEffect Window

Acute onset. Peaks at 2-4 hours, half-life 12-15 hours.

lockCompliance

WADA PROHIBITED

Overview

Clinical Summary

Modafinil is a prescription wakefulness-promoting agent for narcolepsy and shift work disorder. It is used to reduce excessive sleepiness and to sustain alertness during daytime functioning.

Clinical trials show improved wakefulness and reduced fatigue in sleepiness disorders, with cognitive benefits most apparent under sleep deprivation. Some studies show modest improvements in executive function and working memory. Minority evidence supports fatigue reduction in multiple sclerosis and depression-related fatigue. Benefits are meaningful in indicated conditions, but tolerability and interactions vary and require medical supervision.

Weak atypical dopamine reuptake inhibitor that also elevates hypothalamic histamine and orexin. Enhances glutamatergic and reduces GABAergic signaling to promote wakefulness.

Outcomes

What This Is Expected To Influence

Primary Outcomes

  • Reverses cognitive decline and fatigue from sleep deprivation
  • Highly effective treatment for narcolepsy and shift-work sleep disorder

Secondary Outcomes

  • Modest improvement in sustained attention and executive function in healthy adults
  • Lower abuse liability compared to amphetamines

Safety

Contraindications and Interactions

Contraindications

  • Severe hepatic impairment
  • History of Stevens-Johnson Syndrome
  • Severe cardiac conditions (LVH, mitral valve prolapse)
  • History of psychosis or mania

Side effects

  • Headache (~20%)
  • Nausea
  • Anxiety
  • Insomnia
  • Dizziness
  • Decreased appetite
  • Stevens-Johnson Syndrome (very rare, potentially fatal)

Interactions

  • Hormonal contraceptives (reduced efficacy via CYP3A4 induction)
  • Warfarin (altered INR)
  • Cyclosporine (reduced levels)
  • CYP2C19 substrates (increased levels)
  • High-dose caffeine (additive stimulation)

Avoid if

  • History of psychosis or mania
  • Severe anxiety disorders
  • Unstable cardiovascular disease
  • Pregnancy
  • Lactation

Evidence

Study-level References

modafinil-SRC-001RCT Crossover
Sourceopen_in_new

Wesensten NJ, et al. "Performance and alertness effects of caffeine, dextroamphetamine, and modafinil during sleep deprivation." J Sleep Res. 2005.

Population: Healthy adults during 85h sleep deprivation

Key findings: Modafinil and amphetamine were similarly effective at preserving alertness and cognitive performance during severe sleep loss.

Paper content

Modafinil and amphetamine were similarly effective at preserving alertness and cognitive performance during severe sleep loss.

modafinil-SRC-002Systematic review and meta-analysis.
Sourceopen_in_new

Jung J, Youm J, Kang J, Kim AY, Suh JK, Kang HY. Assessing condition-specific adverse event profiles of modafinil for labelled and off-label uses: a systematic review and meta-analysis. Basic Clin Pharmacol Toxicol. 2026;138(1):e70147. doi:10.1111/bcpt.70147. PMID:41367108.

Population: Patients across narcolepsy, obstructive sleep apnea, shift work disorder, ADHD, depression, and other conditions treated with modafinil.

Dose protocol: Meta-analysis of 54 studies across labelled and off-label uses

Key findings: Adverse event profiles are condition-dependent. Narcolepsy patients had elevated diarrhea and nausea. OSA patients had more insomnia, anxiety, and headache. ADHD patients had increased insomnia and appetite reduction.

Notes: Valuable for indication-specific safety counseling.

Paper content

This systematic review and meta-analysis synthesized 54 studies to characterize condition-specific adverse event profiles of modafinil across labelled and off-label uses. The key contribution is showing that adverse event profiles differ by indication. Narcolepsy patients experienced elevated risks of diarrhea and nausea. Obstructive sleep apnea patients showed higher rates of insomnia, anxiety, and headache. ADHD patients had more insomnia and appetite reduction. This is clinically valuable because it moves beyond generic "modafinil side effects" toward indication-specific risk counseling. The analysis does not change the efficacy story but sharpens the safety profile.

modafinil-SRC-003Network meta-analysis of 13 randomized controlled trials.
Sourceopen_in_new

Yan Z, Li J, Yu Y, Qiu S, Wang B, Tang J. Comparative efficacy of new wake-promoting agents for narcolepsy - a network meta-analysis. BMC Neurol. 2025;25(1):466. doi:10.1186/s12883-025-04328-9. PMID:41233821.

Population: Adults with narcolepsy across 13 RCTs comparing wake-promoting agents.

Dose protocol: Network comparison of modafinil/armodafinil, sodium oxybate, pitolisant, and solriamfetol across 13 RCTs

Key findings: All agents effective for narcolepsy. Solriamfetol showed largest ESS reduction. Modafinil maintained competitive efficacy and tolerability.

Notes: Contextualizes modafinil relative to newer alternatives.

Paper content

This network meta-analysis compared four wake-promoting agents for narcolepsy across 13 RCTs. Solriamfetol 300 mg showed the largest ESS score reduction (MD = -4.74). All active agents were superior to placebo. Sodium oxybate had the highest gastrointestinal adverse effect risk. Pitolisant had the highest nausea risk. Modafinil/armodafinil maintained a well-established efficacy and tolerability position within the network. This analysis is useful for contextualizing modafinil relative to newer alternatives and confirms its continued clinical relevance as a first-line option for narcolepsy.

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