4-FA
Aliases: Pfa, Rdj, Flux, 4-fmp, Pal-303, 4-Fluoroamphetamine, 4fa
Categories
Summary
First popularized in Dutch party scenes circa 2010; banned in Netherlands May 2017 after several fatal hypertensive crises and strokes. Street samples vary significantly (60-140 mg per tablet). Users experiencing severe headaches after use should seek immediate medical evaluation. Insufflation is particularly caustic and painful; oral route preferred. DEA announced intent to schedule as Schedule I in United States (June 2025).
Dose Information
| ROA | Light | Common | Strong | Heavy |
|---|---|---|---|---|
| Oral | 40-100mg | 100-130mg | 130-150mg | 150mg+ |
Light
Common
Strong
Heavy
Onset, Duration & After-effects
| ROA | Onset | Comeup | Peak | Offset | After Effects | Total |
|---|---|---|---|---|---|---|
| Oral | 30-60 min | 30-75 min | 2.5-3.5 hrs | 2-3 hrs | 6-12 hrs | 360-0 min |
| Insufflated | 2-10 min | 15-30 min | 2-3 hrs | 2-3 hrs | 6-12 hrs | 240-0 min |
Tolerance
Build-up
develops over days to weeks of regular use
Reset
3–7 days for acute; 1–3 weeks for full reset
Cross-tolerance
Effects
Positive
- Stimulation
- Physical euphoria
- Increased energy/alertness
Negative
- Teeth grinding
- Increased heart rate
- Increased perspiration
- Pupil dilation
- Temperature regulation suppression
- Weight loss
- Sweating
- Bruxism
- Headache
- Temporary erectile dysfunction
- Increased blood pressure
- Seizure
- Abnormal heartbeat
- Dry mouth
- Difficulty urinating
- Decreased need for sleep
- Decreased appetite
- Disturbed sleep patterns
- Itchiness
- Spontaneous bodily sensations
- Muscle contractions
- Increased bodily temperature
- Sleep paralysis
- Stamina intensification
Positive
- Cognitive euphoria
- Empathy, affection, and sociability enhancement
- Motivation enhancement
- Focus enhancement
- Wakefulness
- Anxiety suppression
- Euphoria
- Increased sociability
- Mood lift
- Analysis enhancement
- Empathy, love, and sociability enhancement
- Novelty enhancement
- Thought connectivity
- Unity and interconnectedness
- Increased sense of humor
- Immersion intensification
Negative
- Compulsive redosing
- Aggressiveness
- Anxiety
- Cognitive fatigue
- Depression
- Irritability
- Thought deceleration
- Thought disorganization
- Brain zaps
- Confusion
- Suicidal ideation
- Delirium
- Motivation depression
- Thought acceleration
- Time distortion
- Excessive talking
- Moodiness
- Ego inflation
- Focus intensification
Positive
- Tactile enhancement
- Increased music appreciation
- Increased libido
- Pattern recognition enhancement
- Bodily control enhancement
- Color enhancement
- Auditory acuity enhancement
Negative
- Appetite suppression
- Dehydration
- Disinhibition
- Orgasm depression
- Increased sexuality
- Visual and auditory hallucinations
- Auditory hallucination
- Auditory distortion
- Vibrating vision
- Tactile intensification