Modafinil

Staying awake

The strongest evidence concerns diagnosed sleep disorders. Short trials show improved wakefulness in narcolepsy, treated sleep apnea and shift-work disorder.¹⁰⁸⁷

Sleepiness and cognition

Trials in rested people measure laboratory performance outside clinical sleep disorders. Some laboratory scores improve, others stay unchanged. A complex-task experiment found lower value gained per move under modafinil.^1104,1095

Results in context

The 157-person sleep-apnea trial continued CPAP. The 209-person shift-work trial found improvement alongside persistent impairment. Treatment response needs to be judged in the setting where the person needs to function.^1089,1092

Common questions

01 What is modafinil actually approved for?

In the US, it treats excessive sleepiness linked to narcolepsy, obstructive sleep apnea and shift-work disorder in adults. UK and Korean labels list adult narcolepsy. Japan also lists idiopathic hypersomnia and sleepiness in OSA patients receiving airway treatment.^{1087,1088,1114,1103}

02 Can it replace CPAP?

No. It treats sleepiness, while CPAP or another prescribed treatment addresses the blocked airway. The main OSA trials studied people who continued effective CPAP.^{1087,1089,1090}

03 How much does it help with narcolepsy?

A review of nine narcolepsy trials involving 1,054 participants found an average 2.73-point reduction on the Epworth Sleepiness Scale compared with placebo. Average time awake on the maintenance-of-wakefulness test increased by 2.82 minutes. Individual benefit varied.¹¹¹⁵

04 Why am I still sleepy even with CPAP?

Some people remain sleepy despite effective CPAP. In a four-week trial of 157 such patients, sleepiness scores returned to the normal range in 51% on modafinil and 27% on placebo. The corresponding objective sleep-test comparison was 29% versus 25% and was not statistically significant.¹⁰⁸⁹

05 Does it make driving home after a night shift safe?

Residual sleepiness remained in the shift-work trial. Among 209 workers, 29% on modafinil and 54% on placebo reported an accident or near accident on the commute home. The label calls for reassessment of sleepiness and driving risk.^1092,1087

06 Does it make a rested person smarter?

A review of 14 studies in healthy, rested adults found a small average effect on cognitive tests: standardized mean difference 0.12. The clearest signal was in memory updating. Individual trials found gains on some tasks, unchanged results on others and occasional slower responses.^1104,1094

07 Can it make complex problem-solving worse?

Yes. In a 40-person crossover experiment, modafinil reduced the value gained per move on a complex planning task. Its increases in time spent and number of moves were not statistically significant. The experiment measured a laboratory task.¹⁰⁹⁵

08 How long does it stay in the body?

The US label gives an effective half-life of about 15 hours after repeated doses. The R-enantiomer clears more slowly than the S-enantiomer. Drug elimination does not define the duration of the contraceptive interaction.¹⁰⁸⁷

09 Can it keep me awake when I want to sleep?

Yes. A review of 54 trial reports found more insomnia with modafinil than placebo, with a pooled risk ratio of 2.19. The studies covered different diagnoses, doses and treatment lengths.¹⁰⁹⁶

10 Can it worsen anxiety or bipolar symptoms?

Anxiety and nervousness occur in trials. The label also records postmarketing reports of mania, hallucinations, delusions, aggression and suicidal thoughts. A treatment review includes any history of mood or psychotic illness.¹⁰⁸⁷

11 What should a new rash mean?

The label says to stop at the first rash unless it is clearly unrelated to the drug. Serious reactions can involve the skin and other organs. Blistering, mouth sores, facial swelling or breathing trouble need urgent medical assessment.¹⁰⁸⁷

12 Does it affect blood pressure?

Some patients needed new or increased blood-pressure treatment: 2.4% on modafinil versus 0.7% on placebo in the label’s short-term trials. The label advises considering heart-rate and blood-pressure monitoring.¹⁰⁸⁷

13 Does it interfere with birth control?

Yes. The US label calls for alternative or additional contraception during treatment and for one month afterward. UK guidance and the Korean label specify two months afterward. The relevant product label and contraceptive method need review together.^{1087,1097,1114}

14 What did the newest pregnancy study find?

A 2026 French study recorded major congenital anomalies in 35 of 832 first-trimester-exposed births, or 4.2%, versus 29 of 832 matched unexposed births, or 3.5%. The adjusted comparison was imprecise. UK guidance continues to advise against use during pregnancy.^1098,1097

15 Why do pregnancy studies report different percentages?

They follow different groups and use different comparisons. The final US registry combined modafinil and armodafinil and reported major malformations in 18 of 137 prospective live births, or 13.1%. The French study used national health records and matched comparison groups. These percentages are not interchangeable personal risk estimates.^1116,1098

16 Is armodafinil the same thing?

Armodafinil contains the R-enantiomer. Modafinil contains equal amounts of R and S. They are separate prescription products with different concentration profiles.^1087,1099

17 What happens when someone stops?

Sleepiness returned to baseline during the narcolepsy trial’s two-week discontinuation phase. That trial reported no amphetamine-like withdrawal syndrome during the observation period. Withdrawal symptoms were reported in a later 95-person comparison trial.^1091,1105

18 What does the Chinese evidence add?

A Chinese company dossier describes a 209-person sleep-apnea trial. A separate Chinese abstract reports pharmacokinetics in 20 healthy Uygur and Han volunteers. Without the full trial report and resolved cohort links, these records cannot yet support a larger combined patient count.^{1100,1106,1117,1118}

19 Has it been studied for idiopathic hypersomnia?

Yes. A Japanese placebo-controlled trial randomized 71 people. After three weeks, the wake-test improvement was 5.02 minutes greater with modafinil. A separate open-label extension followed 57 people for up to 52 weeks. Japan’s prescribing information includes idiopathic hypersomnia.^1107,1103

20 Is it approved for children or ADHD?

The US label does not approve modafinil for children or for ADHD. AASM gives a conditional recommendation for pediatric narcolepsy, based on a separate clinical evidence review. Serious rash in pediatric trials remains part of the label warning.^1087,1119

21 How does it compare with amphetamine treatment?

A 12-week trial randomized 44 people with idiopathic hypersomnia or narcolepsy type 2. Sleepiness scores improved by 5.0 points with modafinil and 4.4 with amphetamine-dextroamphetamine. The trial’s main comparison was inconclusive. Seven people stopped modafinil because of side effects, compared with two on the other treatment.^1108,1109

22 What is known about breastfeeding?

Published milk measurements come from two single-person reports. Both report armodafinil levels after the mother took modafinil. In the 2018 report, the infant was not breastfed; the later report observed normal infant growth. Infant follow-up is very limited, so treatment and feeding plans need individual review.^1110,1111

23 Which side effects were most common?

In the US label’s pooled trials, headache occurred in 34% on modafinil and 23% on placebo; nausea in 11% and 3%; and insomnia in 5% and 1%. The comparison included 934 modafinil-treated and 567 placebo-treated participants.¹⁰⁸⁷

24 Is it banned in sport?

Yes. WADA’s 2026 list names modafinil as a non-Specified stimulant prohibited in competition. The published 2027 list retains that status from January 1, 2027.^1120,1121

25 Does the effect wear off with long-term use?

In two pooled narcolepsy extensions, average sleepiness improvement persisted through 40 weeks. Of 478 participants entering the open-label studies, 341 completed them and 43 stopped because of adverse events. These selected prior-trial participants provide useful follow-up, with no concurrent placebo group.^1122,1123

26 Does it treat cataplexy?

The main demonstrated benefit is reduced daytime sleepiness. A review of nine narcolepsy trials found no significant difference in cataplexy frequency versus placebo.¹¹¹⁵

27 Does it help with creative work?

The results are mixed. In a 64-person study, some memory and planning scores improved, but participants taking modafinil scored lower on flexibility in one creativity test. Other creativity measures were unchanged or inconclusive. It was a single-dose laboratory study using one-tailed statistical tests.¹¹¹³

28 Which drug interactions matter?

The label describes changes in exposure to steroidal contraceptives, cyclosporine and several other medicines metabolized by liver enzymes. It also calls for closer monitoring with warfarin. A medication review needs to include prescriptions, supplements and other stimulants.¹⁰⁸⁷

29 Can an online listing prove what is in the tablets?

No. A published study examined 13 online retailers and their claims; it did not chemically test their products. A website’s appearance or customer reviews cannot substitute for laboratory identity and content testing.¹¹²⁴

30 Can someone still feel sleepy while taking it?

Yes. Trials show average improvement, and residual sleepiness can remain. The US label calls for reassessment of daytime sleepiness and driving risk during treatment.^1087,1091

31 What doses and formulations were actually studied?

The approved formulation is an oral tablet. The US label describes 200 mg once daily, with timing tied to the diagnosed sleep disorder. Research trials used their own doses and schedules, which remain attached to those study populations.¹⁰⁸⁷

32 Is reducing sleepiness the same as treating fatigue?

They can respond differently. In a six-week trial involving 20 people after traumatic brain injury, modafinil improved sleepiness and laboratory wakefulness but did not improve fatigue. Results must be interpreted within the underlying diagnosis.¹¹²⁵

33 Does it work for adult ADHD?

A large medication review found no significant modafinil benefit over placebo for clinician-rated adult ADHD symptoms. Adults taking modafinil were more likely to stop because of adverse effects. Modafinil has no US ADHD indication.^1126,1087

34 Has it been studied as an add-on for depression?

Yes. An older review of six trials found a modest average benefit from adding modafinil or armodafinil to existing depression treatment. It pooled both drugs and included major and bipolar depression; the modafinil label also records mania and other psychiatric reactions.^1127,1087