I use amphetamines for certain therapeutic benefits, mostly to improve attention and mood. I enjoy psychedelics for recreational use but will occasionally use amphetamines or MDMA for recreation. Always via oral route.
4-FA
Well-documented
Well-documented
Multiple authoritative sources agree on dosing and effects.
- 6 corroborating sources
- 1 ROA with full dose ladder
- duration data present
- 30 combo interactions documented
- toxicity data (PsychonautWiki)
- classified Research-chemical
Well-documented
Multiple authoritative sources agree on dosing and effects.
- 6 corroborating sources
- 1 ROA with full dose ladder
- duration data present
- 30 combo interactions documented
- toxicity data (PsychonautWiki)
- classified Research-chemical
Aliases: Pfa, Rdj, Flux, 4-fmp, Pal-303, 4-Fluoroamphetamine, 4fa
Summary
4-Fluoroamphetamine (also known as 4-FA, 4-FMP, para-Fluoroamphetamine, PAL-303 and colloquially as Flux) is a novel synthetic amphetamine compound that produces a unique progressive mixture of entactogenic and stimulant effects when administered. It is part of a series of fluorinated amphetamine analog that initially included such compounds as 2-FA, 2-FMA, and 3-FA. Anecdotal reports have described the subjective effects of 4-FA as having a moderate MDMA-like entactogenic onset for the initial few hours of the experience that then gradually transitions into traditional amphetamine-type stimulation (for a total duration of around 6 to 8 hours) with residual effects that can last a few hours afterward.
Dose Information
| ROA | Light | Common | Strong | Heavy |
|---|---|---|---|---|
| Oral | 40-100mg | 100-130mg | 130-150mg | 150mg+ |
Light
Common
Strong
Heavy
Sources
Oral
Dose ladder — dose.wiki, PsychonautWikiOnset, Duration & After-effects
| ROA | Onset | Comeup | Peak | Offset | Total |
|---|---|---|---|---|---|
| Oral | 30-60 min | 30-75 min | 2.5-3.5 hrs | 2-3 hrs | 6-12 hrs |
| Insufflated | 2-10 min | 15-30 min | 2-3 hrs | 2-3 hrs | 4-8 hrs |
Effect Profile
45 reportsScores (0–10) curated from multiple sources:
- Effect keyword matching from PsychonautWiki catalog
- Validated against 27 Erowid trip reports
- Weighted by importance: core (×3), major (×2), minor (×1)
Psychedelic
5.4
Moderate+
5/10
Strong auditory effects with strong body load, moderate visuals, mild headspace
Visual Intensity
×3
6
color enhancement
pattern recognition enhancement
Headspace Depth
×3
5
thought connectivity
time distortion
confusion
Auditory Effects
×1
10
auditory distortion
auditory hallucination
Body Load / Somatic Effects
×1
10
temperature regulation suppression
teeth grinding
bruxism
increased heart rate
sweating
Empathogen
10.0
Extreme
10/10
Strong empathy, euphoria, stimulation, and sensory enhancement
Empathy / Social Openness
×3
10
empathy, affection, and sociability enhancement
empathy, love, and sociability enhancement
increased sociability
Euphoria / Mood Elevation
×2
10
physical euphoria
cognitive euphoria
euphoria
mood lift
Stimulation
×1
10
stimulation
wakefulness
teeth grinding
increased heart rate
Sensory Enhancement
×1
10
tactile enhancement
color enhancement
increased libido
Stimulant
8.8
Intense+
9/10
Strong stimulation, euphoria, and focus with strong anxiety/jitters
Stimulation / Energy
×3
10
stimulation
wakefulness
Euphoria / Mood Lift
×2
10
physical euphoria
cognitive euphoria
euphoria
mood lift
motivation enhancement
Focus / Productivity
×2
10
focus enhancement
analysis enhancement
motivation enhancement
thought acceleration
Anxiety / Jitters
×1
10
anxiety
teeth grinding
increased heart rate
bruxism
sweating
Based on reports from:
Tolerance
Build-up
develops over days to weeks of regular use
Reset
3โ7 days for acute; 1โ3 weeks for full reset
Tolerance Decay
Full tolerance
2d
Half tolerance
7d
Baseline
~14d
Anecdotal: tolerance builds quickly with repeated/weekly use and decays over 2โ4+ weeks; cross-tolerance likely overlaps with other amphetamine-like stimulants and serotonergic releasers. Data quality is limited.
Cross-Tolerances
Effects
Aggregated from 27 single-substance Erowid and 18 Bluelight experience reports; 30 Erowid reports where another drug was taken too are left out
Each bar shows the share of analyzed reports whose text mentions that effect — a mention is not always a first-hand experience (fear of an effect or something witnessed can count). Mentions saying the effect did not happen are left out; that check reads keywords, so it can miss some. The shaded band on a bar, and the small range after its number, is the 95% interval: where the share could plausibly be with other reports of the same kind. Fewer reports, wider band. Tap or hover any number for details. The second value is the Bluelight extractor's per-effect confidence; a dash means the row is Erowid-derived, which has no confidence measurement.
Rows resting on fewer than 20 reports show a count (“3 of 7”) instead of a bar. Why 20?
Effect glossary — · full glossary
Positive Effects 30
73.4% (95% interval 59 to 84 percent)
89%
68.9% (95% interval 54 to 80 percent)
92%
40.0% (95% interval 27 to 54 percent)
82%
37.8% (95% interval 25 to 52 percent)
90%
33.3% (95% interval 21 to 48 percent)
84%
22.2% (95% interval 12 to 36 percent)
82%
17.8% (95% interval 9 to 31 percent)
85%
15.5% (95% interval 8 to 29 percent)
68%
15.5% (95% interval 8 to 29 percent)
82%
8.9% (95% interval 4 to 21 percent)
75%
12 of 18
86%
3 of 18
83%
3 of 18
90%
2 of 18
90%
2 of 18
82%
2 of 18
85%
2 of 18
88%
2 of 18
78%
1 of 18
85%
1 of 18
85%
Show 10 more positive effects
1 of 18
70%
1 of 18
80%
1 of 18
75%
1 of 18
80%
1 of 18
85%
1 of 18
80%
1 of 18
75%
1 of 18
85%
1 of 18
80%
1 of 18
70%
Adverse Effects 30
31.1% (95% interval 20 to 46 percent)
72%
25.9% (95% interval 13 to 45 percent)
–
22.2% (95% interval 11 to 41 percent)
–
18.5% (95% interval 8 to 37 percent)
–
15.6% (95% interval 8 to 29 percent)
75%
14.8% (95% interval 6 to 32 percent)
–
7 of 18
74%
5 of 18
85%
2 of 18
85%
2 of 18
82%
2 of 18
78%
2 of 18
80%
2 of 18
80%
2 of 18
80%
1 of 18
80%
1 of 18
75%
1 of 18
75%
1 of 18
80%
1 of 18
85%
1 of 18
80%
Show 10 more adverse effects
1 of 18
80%
1 of 18
75%
1 of 18
85%
1 of 18
85%
1 of 18
80%
1 of 18
85%
1 of 18
80%
1 of 18
75%
1 of 18
90%
1 of 18
80%
Also reported in combinations. In the 30 4-FA reports where another drug was taken too, 2 (6.7%) mention hospital, emergency services or an overdose, 0 (0.0%) a seizure and 1 (3.3%) psychosis. In the 27 single-substance reports: 3.7%, 0.0% and 0.0%. These are not in the figures above: they cannot be put down to 4-FA alone, and a mention is not always something that happened to the writer.
Combinations
Cross-Check 4-FA with another substanceCommunity Trip Reports
Anecdotal first-person accounts from Reddit, Erowid, Bluelight, and Dose.wiki. Click a source to expand. Reports are harm-reduction context, not medical guidance. Tags summarise each author's own verdict — how reports are classified.
Erowid 8 reports 5 positive 3 neutral visit
My previous experiences: Alcohol, tobacco, weed, magic mashrooms, LSD, ecstasy pills, meth, mephedrone, 3,4-DMMC, 4-MeMABP, diazepam, opiates (codein, morphine, opium, poppy tea). I have to mention that I have opiate habit (2O poppies/daily).
Age: 19 Sex: Male Smoker: avg. ยฝ a pack/day Weight: 75 kg (about 165 lbs) Health: No health problems Medication: No medication Previous experiences: This is my first experience with this compound. Pretty much a novice in the area, Iยve tried DPT, mephedrone, weed, 4-ho-met, DXM, MDPV and now 4-FMP.
Howdy all, just thought I'd throw in my 2 cents about my 4-fa experiences for the general domain of knowledge. I first obtained 3g of this substance about 3 weeks ago and went through the whole 3g in a week, although I was sharing it pretty liberally some nights so my actual intake over a week was probably only 2g.
Substance: 4-FA fluffy white powder, bought from two vendors who both claim 99% purity, product appears identical from both vendors and seems to be from the same batch. Primary dose from one vendor, redoses from the other vendor.
Chemical: 4-Fluoroamphetamine Dose: Approximately 140 mg to 170 mg (powder/crystals) Body: 70 kg or 155 lb Age at time of experience: 19 Experience date: October 30, 2012 Duration of the effects: 8 hours PROLOGUE: I am a 19 year old student. I have experience with Marijuana, Salvia, MDMA, Cocaine and Alcohol.
The 'trip' of this really isn't a dynamic journey as I would experience on a hallucinogen, so I will explain it in more of an outline/timeline of effects. I take recordings of my state and experience on a voice recorder whenever I notice the effects shifting.
Back ground: I'm a 19 year old male, who has been battling drug abuse since I was 15 years old. I've recently come under better control of my drug use, and I'm not doing them as much, but this hasn't been without a few mishaps.
Bluelight 7 threads 3 positive 2 neutral 2 cautionary visit
4-Fluoroamphetamine-First Time-A Wonderful New Discovery! This experience is a few months old, it occurred just after the New Year. I took notes during the experience but have subsequently lost them, so please forgive any gaps in my memory.
Substance: 4-FA fluffy white powder, bought from two vendors who both claim 99% purity, product appears identical from both vendors and seems to be from the same batch. Primary dose from one vendor, redoses from the other vendor.
I have done most every drug you can name at least once; heroin, coke, LSD, MDMA, you name it. I've always preferred sertogenic stimulants over any other type of drug however, and I abused them as much as I could. Nothing was like 4-FA however.
23/10/2011 - 4-FA, Alcohol 17:31 - 128mg taken (128mg total) (4-FA) 20:14 - 104mg taken (232mg total) (4-FA) 00:50 - 1 Magners (440ml, 4.5% ) 01:11 - 1 Kopparberg (500ml, 4.5% ) Notes: 15:00 - Last ate All doses taken orally 20mg Cipralex taken daily 96 days since last stim (JGG, JWG) 21:26 - 500mg Magnesium 21:40 - 1/...
While having tried alot of sibutramine recently, as well as other substances, none of these motivated me to write about them in the same way as I am doing currently for the title compound.
Taken from my report on erowid 4-Fluoroamphetamine -------------------------------------------------------------------------------- DOSE : 150 mg oral 4-Fluoroamphetamine (powder / crystals) BODY WEIGHT : 70 lb INTRODUCTION: 4-fluoro alpha-methylphenethylamine, or 4-FMP/4-FA for short is a largely unknown substance.
Not a particularly detailed report because the events do not necessitate details. Received 1 g 4-FA this afternoon. Measured 30 mg and insufflated in two lines. Stings, but not as bad as other have made it out to be, and certainly nothing like 2C-xyz. After a few minutes, a notably clear and focused headspace arises.
4-FA's nerd page
Pharmacology, chemical data, effect profiles, and more
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Helpful Links
Add missing routes to PsychonautWiki Journal
The PsychonautWiki Journal app already has 4-FA, but its built-in entry only covers Oral. Here are the other routes we have data for. You can't edit a built-in substance, but you can add a Custom Unit for any of these routes to log it.
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Duration (reference)
4-FA: routes the PsychonautWiki Journal app is missing Source: SubstanceSearch (substancesearch.com) Insufflated duration: onset 2-10m ยท come-up 15-30m ยท peak 2-3h ยท offset 2-3h ยท total 4-8h ยท after-effects 6-12h Note: ranges are harm-reduction guidance, not a prescription. Start low, go slow, and test your substances.
Ranges are harm-reduction guidance, not a prescription.
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