Fenproporex
An amphetamine prodrug anorectic historically popular in Brazil and parts of Europe. It is metabolised to amphetamine, giving it real appetite-suppressing power alongside amphetamine-type cardiovascular and dependence risks; it too causes positive amphetamine drug screens.
01 Overview
Fenproporex is a 3-(1-phenylpropan-2-ylamino)propanenitrile that is cleaved in vivo to amphetamine. It was one of the most widely prescribed appetite suppressants in Brazil before regulatory crackdowns and was a common component of illicit compounded 'diet pill' formulas.
As with clobenzorex, its clinical effect and its risks flow largely from the amphetamine it releases. It is controlled internationally and no longer widely marketed.
02 Mechanism
A prodrug metabolised to amphetamine, releasing dopamine and noradrenaline to suppress appetite and produce central stimulation.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Typical anorectic dose | 20–40 mg/day | Oral | Historically 20-40 mg/day of the sustained-release form for short-term use. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Appetite suppressionReduced hunger and intake via its amphetamine metabolite. | short-term weight loss | Observational | |
| Increased alertnessWakefulness and energy from released amphetamine. | amphetamine-like | Observational |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Insomnia and anxietyOverstimulation, restlessness and disturbed sleep. | Moderate | Common | Observational | |
| Cardiovascular stimulationTachycardia and raised blood pressure. | Moderate | Common | Observational |