3-FEA Facts
Stimulant;
Description
3-FEA (N-ethyl-3-fluoroamphetamine) is a synthetic stimulant-empathogen of the substituted amphetamine class. It floods the brain with dopamine, norepinephrine, and serotonin by reversing the transporters that normally clear them.[1][2]
Subjective effects include stimulation, emotional warmth, tactile enhancement, euphoria, and paradoxical waves of sedation. The experience sits between a pure stimulant and an entactogen — serotonin-driven warmth and openness layered over a background of catecholamine drive.
Physical dependence develops after repeated use, and the main acute danger is cardiovascular.[1][3] A structurally related compound caused severe cardiac events in 40% of emergency cases; combining 3-FEA with MAOIs or serotonin-raising drugs adds the risk of catastrophic overheating and blood pressure crises.
Dose and durationby route · individual sensitivity varies
Starts in 20 – 60 minLasts 4 – 6 hoursAfter-effects 6 – 12 hours
Body and dependence
- Acute toxicity
- Moderate
- Chronic toxicity
- Moderate
- Physical dependence
- Moderate
- Psychological dependence
- Moderate
- Withdrawal
- Moderate
- Compulsive redosing
- Moderate
Tolerance
- Builds
- Moderate
- Fully resets after
- 5 days
- Carries over to
- amphetamine;
MDMA; cathinones; 4-FA; 3-FA; serotonergic compounds
Effectslikely at a common dose
- Perception
- Touch enhancement;
+7 possible - Body
- Stimulation;
Insomnia; Vasoconstriction; Dry mouth; Appetite suppression; Pupil dilation; Wakefulness; +21 possible, including Temperature dysregulation, Heart rate perception changes, Excessive sweating - Thinking
- Thought acceleration;
Cognitive euphoria; +17 possible, including Compulsive redosing urge - Feeling
- Euphoria;
Empathy enhancement; +10 possible, including Anxiety, Anhedonia, Emotional lability - Self
- none likely · 9 possible, including Craving, Ego inflation
- Awareness
- none likely · 2 possible
Who shouldn't take it
Combinations61 recorded
Seek help immediately if
- Chest pain; racing, pounding, or irregular heartbeat
- Very high body temperature; heavy sweating; hot, flushed skin
- Severe agitation, paranoia, panic, or confusion
- Severe headache; muscle rigidity or twitching
- Seizures
- Signs of stroke — face drooping, one-sided weakness, slurred speech
- Difficulty breathing; collapse or unconsciousness
What to do
- Call emergency services for chest pain, overheating, seizure, or unresponsiveness
- Move them to a cool, quiet place and reduce stimulation
- Cool the body — remove excess clothing, apply cool damp cloths, fan them
- Keep them calm; reassure — panic worsens the cardiovascular strain
- If seizing, protect from injury (don't restrain); recovery position afterward
- Monitor breathing and be ready to give rescue breaths / CPR
Most stimulant overdoses settle with cooling, a calm environment, and time. The medical danger is hyperthermia, cardiac events (arrhythmia, heart attack, stroke), and seizures — get help immediately if any appear.
988 Suicide & Crisis LifelineFireside Project: 62-FIRESIDE
References
- [1]^abJo C, Joo H, Lim NY, Park SJ, Choi SO (2024) Withdrawal from 3-Fluoroethamphetamine induces hyperactivity and depression-like behaviors in male mice — Journal of Neuroscience Research doi:10.1002/jnr.25251
- [2]^Luethi D, Liechti ME (2020) Designer drugs: mechanism of action and adverse effects — Archives of Toxicology doi:10.1007/s00204-020-02693-7
- [3]^Gresnigt FMJ, Snik A, Franssen EJF, Vanhommerig JW, de Lange DW, Riezebos RK (2022) 4-Fluoroamphetamine (4-FA) intoxication results in exaggerated blood pressure effects compared to MDMA and amphetamine: A retrospective analysis — Journal of the American College of Emergency Physicians Open doi:10.1002/emp2.12813