4-Fluoroethamphetamine
4-Fluoroethamphetamine (4-FEA) is a para-fluorinated N-ethyl amphetamine. Like other 4-fluoro substituted amphetamines it is reported to carry more entactogenic, serotonergic character than the 2-fluoro isomers, but it remains almost entirely uncharacterised in humans.
01 Overview
Para-fluorination of the amphetamine ring tends to shift activity toward serotonin release, producing a more MDMA-like, entactogenic quality than purely stimulant analogues. 4-FEA combines this para-fluoro pattern with an N-ethyl group and was sold as a research chemical.
There is no controlled human data. The serotonergic character raises specific concern about serotonin toxicity when combined with other serotonergic drugs, but this risk is inferred from related compounds rather than directly documented for 4-FEA.
02 Mechanism
Presumed mixed dopamine, noradrenaline and serotonin releaser, with relatively greater serotonergic activity from para-fluorination.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Light | 20–50 mg | Insufflated | Unstudied; not recommended given serotonergic character. |
| Common | 30–80 mg | Oral | Anecdotal only; no validated dosing. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Entactogenic mood liftReported warmth and emotional openness, milder than MDMA. | Anecdotal | ||
| StimulationIncreased energy and wakefulness. | Anecdotal | ||
| Increased sociabilityTalkativeness and sociability. | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Post-use low moodDepleted mood in the days after use, as with serotonergic stimulants. | Moderate | Common | Anecdotal | |
| Tachycardia and hypertensionRaised heart rate and blood pressure. | Severe | Common | Anecdotal | |
| Serotonin toxicity riskCombining with SSRIs, MAOIs or other serotonergic agents may precipitate serotonin syndrome. | Life-threatening | Unknown; risk with serotonergic combinations | Unconfirmed |