armodafinil
updated
Armodafinil, sold as Nuvigil, is the R enantiomer of modafinil, a Schedule IV prescription drug approved in the US for excessive sleepiness in adults with narcolepsy, obstructive sleep apnea or shift-work disorder. It is also taken as a cognitive enhancer and a stand-in for sleep. In a 196-person, 12-week narcolepsy trial it improved measured wakefulness over placebo, but shift workers kept marked residual sleepiness and no trial shows better cognition in rested people. Graded A for the approved sleepiness uses; serious rash and psychiatric reactions are label risks.
Small-molecule prescription wakefulness drug
- Two randomized studies found better wakefulness and simple sustained attention during one acute sleep-loss episode in healthy men.
- In shift-work disorder, wake latency improved from 2.3 to 5.3 minutes; substantial residual sleepiness remained.
- The terminal half-life is about 15 hours, which can extend exposure into intended sleep.
- A 2025 seven-day Chinese PK study reported fever in 6/12 and 7.8-fold sulfone-metabolite accumulation.
How is armodafinil related to modafinil?
Armodafinil is the isolated R enantiomer of modafinil and a separate US Schedule IV prescription drug.
Its label covers excessive sleepiness associated with adult narcolepsy, obstructive sleep apnea and shift-work disorder. In OSA it treats sleepiness while airway therapy remains necessary; it does not open the airway.
source: Nuvigil US prescribing information, Apotex. Nuvigil (armodafinil), US prescribing information, 2025 record.
source: PubChem: armodafinil chemical identity, National Library of Medicine. PubChem CID 9690109.
How much did it help in narcolepsy?
In a 196-person, 12-week trial, armodafinil improved objective wakefulness and clinician-rated global change versus placebo.
Mean morning-to-afternoon wake latency changed by +1.3 and +2.6 minutes in the 150 and 250 mg groups versus −1.9 minutes with placebo. At least minimal global improvement occurred in 69% and 73% versus 33%. This is treatment of pathological sleepiness, not extra cognition above a healthy baseline.
source: The efficacy and safety of armodafinil as treatment for adults with excessive sleepiness associated with narcolepsy., Harsh JR et al. Current medical research and opinion. 2006. PMID 16684437. DOI 10.1185/030079906X100050.
Does it preserve performance after staying awake?
Yes for wakefulness and simple sustained attention during one acute sleep-loss episode. Two randomized healthy-male studies found longer wake latency and fewer vigilance lapses.
In 107 men, every tested 100 to 300 mg dose improved wake latency and psychomotor-vigilance lapses. In 135 men undergoing 24-hour sleep loss, wake latency was 27.6 minutes with armodafinil versus 15.3 with placebo.
Neither study proves normal judgment, learning, creativity, driving safety or repeated use while chronically sleep deprived. The dose-ranging trial also found lower subsequent sleep efficiency and some blood-pressure or pulse increases.
source: Pharmacodynamic effects on alertness of single doses of armodafinil in healthy subjects during a nocturnal period of acute sleep loss., Dinges DF et al. Current Medical Research and Opinion. 2006. PMID 16393442.
source: Maintenance of wakefulness with lisdexamfetamine dimesylate, compared with placebo and armodafinil in healthy adult males undergoing acute sleep loss., Gasior M et al. Journal of Clinical Psychopharmacology. 2014. PMID 25159886.
What improved in shift-work disorder, and what did not?
A 12-week trial improved nighttime wakefulness, attention, reaction time and selected episodic-memory measures, but left marked residual sleep propensity.
The trial enrolled 254 shift workers, treated 245 and analyzed efficacy in 216; 68/245 withdrew. Mean nighttime sleep latency rose from 2.3 to 5.3 minutes versus 2.4 to 2.8 with placebo. Attention continuity and delayed recall improved, while speed of memory did not survive the final analysis.
A mean five-minute wake latency is still severe sleepiness. Diary reports of fewer errors were self-reported, and one suicidal-ideation serious event in a participant with prior depression was considered possibly related.
source: Armodafinil for treatment of excessive sleepiness associated with shift work disorder: a randomized controlled study., Czeisler CA et al. Mayo Clinic proceedings. 2009. PMID 19880686. DOI 10.1016/S0025-6196(11)60666-6.
Is armodafinil proven better than modafinil?
No. A 211-person shift-work trial reported response rates of 72.12% with armodafinil and 74.29% with modafinil and did not show superiority.
The trial used subjective sleepiness and was not an equivalence study. Higher late-shift R-enantiomer exposure in a different acute trial cannot be converted into general clinical superiority.
source: Armodafinil versus Modafinil in Patients of Excessive Sleepiness Associated with Shift Work Sleep Disorder: A Randomized Double Blind Multicentric Clinical Trial., Tembe DV et al. Neurology research international. 2011. PMID 21766023. DOI 10.1155/2011/514351.
Is armodafinil a general cognitive enhancer?
No consistent global effect appears across disease cohorts, and the cited evidence contains no armodafinil-specific rested-healthy enhancement trial.
A 33-person multiple-sclerosis crossover found delayed verbal recall benefit after correction, while executive function, visual memory, processing speed and fatigue were null. A four-week HIV-fatigue trial improved fatigue but not global cognition. A 60-person schizophrenia trial found no apparent MATRICS composite benefit.
Modafinil studies tested the racemate and do not establish the effect of the isolated R enantiomer.
source: Impact of armodafinil on cognition in multiple sclerosis: a randomized, double-blind crossover pilot study., Bruce J et al. Cognitive and Behavioral Neurology. 2012. PMID 22960434.
source: Effect of armodafinil on cognition in patients with HIV/AIDS and fatigue., McElhiney M et al. Journal of Clinical and Experimental Neuropsychology. 2013. PMID 23944194.
source: Armodafinil as adjunctive therapy in adults with cognitive deficits associated with schizophrenia: a 4-week, double-blind, placebo-controlled study., Kane JM et al. Journal of Clinical Psychiatry. 2010. PMID 20816042.
What does a 15-hour half-life mean?
A 15-hour terminal half-life means armodafinil leaves the body slowly. Useful focus does not necessarily last 15 hours, and late exposure can disrupt intended sleep.
In pooled healthy-subject studies, peak concentration occurred around two hours fasting, food delayed the peak two to four hours, steady state appeared by day 7, and exposure at steady state was about 1.8 times a single dose.
In 12 healthy Chinese participants taking 200 mg for seven days, parent exposure accumulated 1.5-fold, the sulfone metabolite 7.8-fold, and fever occurred in 6/12. That study measured PK and safety, not benefit.
source: Nuvigil US prescribing information
source: Pharmacokinetic profile of armodafinil in healthy subjects: pooled analysis of data from three randomized studies., Darwish M et al. Clinical Drug Investigation. 2009. PMID 19133704.
source: Pharmacokinetics and Safety of Armodafinil in Chinese Healthy Humans After Multiple-Dose Oral Administration., Lang L et al. Clinical Pharmacology in Drug Development. 2025. PMID 40613661.
What about the Chinese microneedle patch?
The experimental transdermal patch has only been tested in sleep-deprived mice. It is not an approved human route.
Selected animal cognition measures and exposure changed. Those findings cannot define a human patch dose or replace oral-tablet clinical evidence.
source: Application of armodafinil-loaded microneedle patches against the negative influence induced by sleep deprivation, Zhu L, Zhang S, Yu X, Zhu S, Ou G, Li Q, Zhang Y, Wang L, Zhuang X, Du L, Jin Y. Application of armodafinil-loaded microneedle patches against the negative influence induced by sleep deprivation. European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V. 2021. DOI 10.1016/j.ejpb.2021.10.009.
Which risks matter in real use?
Serious rash or multiorgan hypersensitivity, psychiatric reactions, cardiovascular effects, persistent sleepiness and drug interactions are central label risks.
Hormonal contraception can become less effective during treatment and for one month afterward. Headache, nausea, dizziness and insomnia are common. Mania, hallucinations, aggression and suicidal ideation have been reported.
Average improvement never guarantees safe driving or cancels accumulated sleep debt. Late exposure can erode the next sleep opportunity.
Studies and sources
Nuvigil US prescribing information
FDA prescribing information
Apotex. Nuvigil (armodafinil), US prescribing information, 2025 record.
Armodafinil is approved for adult excessive sleepiness associated with narcolepsy, OSA, or shift-work disorder; the label includes serious skin/hypersensitivity, psychiatric, cardiovascular, driving, and contraceptive cautions.
- Participants / model
- Adults with the specified sleep disorders
- Study design
- Prescribing information
Approval concerns a prescription formulation and defined indications; it does not establish healthy-person enhancement.
Read the original sourceThe efficacy and safety of armodafinil as treatment for adults with excessive sleepiness associated with narcolepsy.
Primary human study
Harsh JR et al. Current medical research and opinion. 2006. PMID 16684437. DOI 10.1185/030079906X100050.
In 196 adults, armodafinil improved objective wakefulness and global clinical ratings versus placebo.
- Participants / model
- 196 adults with narcolepsy
- Follow-up
- 12 weeks
- Study design
- Randomized multicenter double-blind placebo trial
The trial addresses narcolepsy, not general enhancement in rested healthy people.
Read the original sourceArmodafinil for treatment of excessive sleepiness associated with shift work disorder: a randomized controlled study.
Primary human study
Czeisler CA et al. Mayo Clinic proceedings. 2009. PMID 19880686. DOI 10.1016/S0025-6196(11)60666-6.
Nighttime sleep latency improved from 2.3 to 5.3 minutes with armodafinil versus 2.4 to 2.8 with placebo.
- Participants / model
- 254 enrolled; 245 treated in safety analysis; 216 in efficacy analysis
- Follow-up
- 12 weeks
- Study design
- Randomized placebo-controlled trial
- Funding
- Cephalon funded, co-designed and managed the trial and performed the initial analysis; an academic group independently replicated the analysis.
68/245 treated participants withdrew. Analyses required postbaseline data and used the last available observation. Mean final sleep latency remained only 5.3 minutes. One serious suicidal-ideation event in a participant with prior depression was considered possibly treatment-related.
Read the original sourceArmodafinil versus Modafinil in Patients of Excessive Sleepiness Associated with Shift Work Sleep Disorder: A Randomized Double Blind Multicentric Clinical Trial.
Primary human study
Tembe DV et al. Neurology research international. 2011. PMID 21766023. DOI 10.1155/2011/514351.
Responder rates were 72.12% with armodafinil and 74.29% with modafinil; no significant efficacy difference was demonstrated.
- Participants / model
- 211 Indian patients with shift-work sleep disorder
- Follow-up
- 12 weeks
- Study design
- Randomized double-blind active comparison
- Funding
- Emcure Pharmaceuticals supplied investigational products and research grants.
The trial was powered to detect a 19-percentage-point response difference, not designed to demonstrate equivalence. It found no significant response difference between armodafinil and modafinil; objective overnight sleep testing was not performed.
Read the original sourcePubChem: armodafinil chemical identity
Government chemical identity database
National Library of Medicine. PubChem CID 9690109.
C15H15NO2S; molecular weight 273.4 g/mol.
- Participants / model
- Chemical record
- Follow-up
- Living database
- Study design
- Curated structure record
Formula and molecular weight establish the recorded structure, not the contents of a retail product or an effective dose.
Read the original sourceApplication of armodafinil-loaded microneedle patches against the negative influence induced by sleep deprivation
Preclinical primary formulation study
Zhu L, Zhang S, Yu X, Zhu S, Ou G, Li Q, Zhang Y, Wang L, Zhuang X, Du L, Jin Y. Application of armodafinil-loaded microneedle patches against the negative influence induced by sleep deprivation. European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V. 2021. DOI 10.1016/j.ejpb.2021.10.009.
An experimental patch changed exposure and improved selected cognitive measures in sleep-deprived mice.
- Participants / model
- Sleep-deprived mice; China-based formulation research
- Study design
- Microneedle formulation, pharmacokinetic and animal behavioral experiments
This preclinical mouse study does not authorize a patch or validate human transdermal dosing.
Read the original sourcePharmacodynamic effects on alertness of single doses of armodafinil in healthy subjects during a nocturnal period of acute sleep loss.
Primary human randomized challenge study
Dinges DF et al. Current Medical Research and Opinion. 2006. PMID 16393442.
All four armodafinil doses increased wake latency and reduced psychomotor-vigilance lapses during one night of sleep loss; effects varied with dose and concentration.
- Participants / model
- 107 healthy men aged 18 to 40 undergoing acute nocturnal sleep loss
- Follow-up
- One sleep-loss night with nine-day safety follow-up
- Study design
- Double-blind placebo- and active-controlled dose-ranging trial
This supports acute vigilance under sleep loss, not complex cognition, rested enhancement or safe repeated sleep restriction.
Read the original sourceMaintenance of wakefulness with lisdexamfetamine dimesylate, compared with placebo and armodafinil in healthy adult males undergoing acute sleep loss.
Primary human randomized challenge study
Gasior M et al. Journal of Clinical Psychopharmacology. 2014. PMID 25159886.
Armodafinil increased overnight wake latency to 27.6 minutes versus 15.3 with placebo and improved sustained attention during 24-hour sleep loss.
- Participants / model
- 135 healthy men undergoing 24-hour sleep loss across armodafinil, lisdexamfetamine and placebo arms
- Follow-up
- One acute sleep-loss episode
- Study design
- Randomized double-blind active- and placebo-controlled trial
Armodafinil was an active control; this does not establish repeated operational safety or sleep replacement.
Read the original sourcePharmacokinetic profile of armodafinil in healthy subjects: pooled analysis of data from three randomized studies.
Primary human pharmacokinetic analysis
Darwish M et al. Clinical Drug Investigation. 2009. PMID 19133704.
Peak concentration occurred around two hours fasting, mean half-life was about 15 hours, and steady-state exposure was about 1.8 times single-dose exposure.
- Participants / model
- 119 healthy participants across three randomized studies
- Follow-up
- Single doses and repeated dosing up to 14 days
- Study design
- Pooled single- and multiple-dose pharmacokinetic studies
Food delayed the peak by two to four hours; elimination half-life does not equal useful-focus duration.
Read the original sourcePharmacokinetics and Safety of Armodafinil in Chinese Healthy Humans After Multiple-Dose Oral Administration.
Primary human pharmacokinetic study
Lang L et al. Clinical Pharmacology in Drug Development. 2025. PMID 40613661.
Armodafinil accumulated 1.5-fold and its sulfone metabolite 7.8-fold after seven days; fever occurred in 6/12 participants.
- Participants / model
- 12 healthy Chinese participants
- Follow-up
- 200 mg daily for seven days
- Study design
- Single-center self-controlled repeated-dose study
No efficacy outcome was measured; the indexed abstract does not provide a comparator arm or complete event table.
Read the original sourceImpact of armodafinil on cognition in multiple sclerosis: a randomized, double-blind crossover pilot study.
Primary human randomized study
Bruce J et al. Cognitive and Behavioral Neurology. 2012. PMID 22960434.
A single 250 mg dose improved delayed verbal recall after correction, while executive function, visual memory, processing speed and fatigue were null.
- Participants / model
- 33 randomized people with multiple sclerosis; 30 analyzed
- Follow-up
- Single-dose periods
- Study design
- Double-blind placebo crossover pilot
Small disease-cohort result requiring replication; not healthy-rested enhancement.
Read the original sourceEffect of armodafinil on cognition in patients with HIV/AIDS and fatigue.
Primary human randomized study
McElhiney M et al. Journal of Clinical and Experimental Neuropsychology. 2013. PMID 23944194.
Fatigue response favored armodafinil, but global cognitive change did not; mood differences disappeared when fatigue-related items were removed.
- Participants / model
- 70 randomized adults with HIV-related fatigue; 61 completed both cognitive assessments
- Follow-up
- Four weeks
- Study design
- Four-week placebo-controlled trial
Repeated-test improvement occurred in both groups; the result does not establish a direct antidepressant or cognition effect.
Read the original sourceArmodafinil as adjunctive therapy in adults with cognitive deficits associated with schizophrenia: a 4-week, double-blind, placebo-controlled study.
Primary human randomized study
Kane JM et al. Journal of Clinical Psychiatry. 2010. PMID 20816042.
MATRICS cognitive-composite change was similar across placebo and 50, 100 and 200 mg armodafinil groups.
- Participants / model
- 60 stable antipsychotic-treated adults with schizophrenia
- Follow-up
- Four weeks
- Study design
- Four-week double-blind placebo-controlled dose-ranging study
An exploratory negative-symptom signal at 200 mg did not establish cognitive enhancement.
Read the original sourceWhy is armodafinil in A tier?
A applies to excessive sleepiness in approved adult sleep disorders. Evidence is also strong for acute vigilance under sleep loss, but not for sleep replacement, global cognition, rested enhancement, anxiety treatment, strength or longevity.
read Armodafinil in the reptides guide, chapter 27: 9 pages, free to read.
how tiers are graded: methodology · every cited source · about reptides.
Research reference, not medical advice. Entries distinguish product labels, study doses and reported protocols. Check the linked source for the product, route and population.