Modafinil — EU research guide.

What is Modafinil?

Modafinil (2-[(diphenylmethyl)sulfinyl]acetamide) is a synthetic wakefulness-promoting drug, first authorised as a prescription medicine (Provigil in the US, Modiodal in several EU countries) to treat excessive sleepiness. The exact mechanism of action is not fully established; inhibition of the dopamine transporter is commonly proposed, but this was not verified against the label text. It is a racemate of R- and S-enantiomers. Research vendors sell it as bulk powder, which is not the same as a licensed, quality-controlled medicine.

What does the research show?

In the US Modafinil in Narcolepsy Multicenter Study (21 centres; 271 patients randomised to two active arms or placebo for 9 weeks), modafinil improved objective wakefulness tests (Multiple Sleep Latency Test, Maintenance of Wakefulness Test) and Epworth Sleepiness Scale scores versus placebo, without adversely affecting nocturnal sleep. In shift-work sleep disorder (Czeisler 2005; 209 patients; 3 months), clinical improvement on the Clinical Global Impression scale was 74% with modafinil versus 36% with placebo, although the authors noted residual sleepiness. A 2016 meta-analysis of 10 randomised trials (1,466 participants) of modafinil or armodafinil in obstructive sleep apnoea with residual sleepiness found an Epworth improvement of 2.2 points (95% CI 1.5-2.9) and a Maintenance of Wakefulness Test gain of about 3 minutes (95% CI 2.1-3.8) over placebo, with more adverse events and more withdrawals due to adverse events. The EMA judged in 2010-2011 that in conditions other than narcolepsy the benefit did not outweigh the safety risks, and it noted concern about off-label and recreational use for performance enhancement. Evidence in healthy people was not reviewed for this guide.

EU legal status

Modafinil is an authorised medicine in the EU (prescription-only status was confirmed for Belgium and the UK, other member states were not checked), but only through national procedures (for example Modiodal, Provigil, Vigil, Modasomil and generics), not a central EU authorisation. After an Article 31 referral the EMA committee concluded in 2010 (initial opinion 22 July 2010; opinion after re-examination 18 November 2010) that modafinil should be used only for narcolepsy, and the European Commission decision followed on 27 January 2011. Obstructive sleep apnoea, shift-work sleep disorder and idiopathic hypersomnia were removed as indications; the harmonised SmPC indicates it in adults for excessive sleepiness associated with narcolepsy with or without cataplexy. In the US it is a Schedule IV controlled substance; national controlled-substance status in EU member states was not verified for this guide. Bulk modafinil powder from research vendors has no marketing authorisation, and modafinil is listed as prohibited (S6.A, non-specified stimulants) on reproductions of the 2026 WADA Prohibited List; the WADA original was not accessible and in-competition versus year-round status was not re-checked (stimulants are normally prohibited in-competition only).