Comparison
Modafinil vs Adrafinil
Modafinil
A eugeroic, a wakefulness-promoting compound, originally developed for narcolepsy. The most-studied prescription cognitive enhancer outside of ADHD treatment. Produces 12–15 hour windows of sustained alertness without the euphoria, abuse potential, or cardiovascular load of amphetamines. Prescription-only in nearly every jurisdiction.
Adrafinil
Prodrug of modafinil. Converted in the liver. Used historically before modafinil was widely available.
| Field | Modafinil | Adrafinil |
|---|---|---|
| Category | stimulant | stimulant |
| Dose range | 100–200mg | 300–1200mg |
| Half-life | 14h | 1h |
| Onset | 45min | 60min |
| Evidence | EVIDENCEA | EVIDENCEB |
| Safety | ●●●○○ | ●●●○○ |
| Legal (US) | USSchedule IV | USUnscheduled |
| PubMed refs | 3200 | 60 |
The comparison in plain English
Adrafinil is a prodrug, your liver converts it into modafinil. It was the original commercial form before modafinil was synthesized directly. Adrafinil is unscheduled in most jurisdictions where modafinil is prescription-only, which is why it persists.
Bottom line
If you can get a modafinil prescription, take modafinil. Adrafinil works through the same active metabolite but adds 30–60 minutes of onset delay and meaningful hepatic stress over time. The legal-status advantage matters only if prescription access is impossible.
Choose Modafinil if
You have prescription access. The risk-benefit is clearly better, direct active compound, no liver enzyme load, well-characterised dose-response.
Choose Adrafinil if
You explicitly need an unscheduled compound and you commit to monitoring liver enzymes (ALT, AST, GGT) periodically. Cycle off after 4–6 weeks of use.