Summary
Fenfluramine was withdrawn from market as an appetite suppressant in 1997 due to cardiotoxicity (valvular heart disease and pulmonary hypertension). Reintroduced in 2020 for seizures associated with Dravet syndrome and Lennox-Gastaut syndrome at lower therapeutic doses. Available only through restricted REMS program requiring cardiac monitoring via echocardiogram. At high recreational doses (80-400 mg), can produce psychedelic effects resembling LSD, along with euphoria, sedation, anxiety, and adverse reactions. Contraindicated in patients with history of cardiac disease.
Dose Information
Light
Common
Strong
Heavy
Onset, Duration & After-effects
| ROA | Onset | Comeup | Peak | Offset | After Effects |
|---|---|---|---|---|---|
| Oral | 30-60 min | 1-2 hrs | 3-5 hrs | 3-6 hrs | 6-12 hrs |
Tolerance
Build-up
develops over days to weeks of regular use
Reset
3–7 days for acute; 1–3 weeks for full reset
Effects
Positive
- Muscle relaxation
- Anxiolytic
- Muscle Relaxant
- Physical euphoria
Negative
- Lethargy
- Nausea
- Motor impairment
- Respiratory depression
- Sedation
- Sedative
Positive
- Euphoria
- Anxiety suppression
Negative
- Anxiety
- Dizziness
- Cognitive impairment
- Amnesia
- Motor control loss
- Thought deceleration
- Decreased arousal
- Time distortion
Positive
Negative
- Appetite suppression
- Disinhibition
- Decreased Libido
- Acuity Suppression
- Visual acuity suppression
- Acuity suppression
- Hallucinations
- Dulled perception
- Perception of bodily heaviness
- Appetite fluctuation