Comparison
Hydrafinil vs Adrafinil
Hydrafinil: clean, fast-taper stimulant; Adrafinil: slow-modafinil prodrug with longer tail and hepatic load.
Hydrafinil
Eugeroic / Wakefulness-Promoting Agent
Adrafinil
Eugeroic (Modafinil Prodrug)
Effectiveness Profile
At a Glance
| Hydrafinil | Adrafinil | |
|---|---|---|
| Type | Nootropic | Nootropic |
| Legal status | Research | Grey-Market |
| Half-life | 4–6 hours (subjective; no published serum t½) | ~1 hour (parent); 12–15 hours (modafinil metabolite) |
| Preferred route | Oral | Oral |
| Dose frequency | as-needed | as-needed |
| Beginner dose | 25–50 mg | 300–300 mg |
| Intermediate dose | 50–100 mg | 300–600 mg |
| Advanced dose | 100–150 mg | 900–1200 mg |
| Cycle length | 1–3 wks | 1–2 wks |
| Time to peak | 1h | 1h |
| Active duration | 5h | 10h |
| Storage | Room temperature, dry, protected from light | Room temperature, sealed, away from light and humidity |
| PCT required | No | No |
| Ancillaries required | No | No |
| Safe for women | Yes | Yes |
Verdict
Hydrafinil wins for quick onset, shorter duration (~4–6h), minimal hepatic strain, and lack of CYP2C19 interaction. Ideal when a tight focus window and easy off-ramp are priorities, or when compounding with SSRIs, oral AAS, or other CYP2C19 substrates.
Adrafinil wins for longer-lasting wakefulness (8–10h modafinil-equivalent), easier sourcing, and modafinil-like effects where availability or legal status blocks direct modafinil procurement. Provides a familiar focus profile to experienced modafinil users but with slower onset and noticeably more hepatic enzyme elevation risk.
Pick A or B?
Pick Hydrafinil if:
- A 4–6 hour clean focus window is needed, with minimal after-effects at night.
- Avoiding hepatic stress is a priority (e.g., running orals, high-cycle support).
- CYP2C19 drug interactions must be minimized (SSRI, hormonal support, etc.).
- Appetite suppression or mild energy lift is needed during a cut without insomnia risk.
- Quick onset and tight control over work/study periods are desired.
Pick Adrafinil if:
- An 8–10 hour sustained wakefulness effect is needed (all-day productivity, shift work).
- Direct modafinil sourcing is impractical or carries legal risk; adrafinil remains accessible.
- Tolerance rotation with hydrafinil/modafinil is part of the protocol.
- Longer, less jittery cognitive enhancement is preferred over a sharper, briefer peak.
- The hepatic profile is actively managed with support (TUDCA, intermittent cycling).