|Summary sheet: 4-FA|
|Common names||4-FA, 4-FMP, PAL-303, Flux|
|Substitutive name||4-Fluoroamphetamine, para-Fluoroamphetamine|
|Psychoactive class||Stimulant / Entactogen|
|Routes of Administration|
4-Fluoroamphetamine (also known as 4-FA, 4-FMP, para-Fluoroamphetamine, PAL-303 and colloquially as Flux) is a novel synthetic substituted 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.
4-FA is rarely found on the streets but commonly sold as a grey area research chemical by online vendors along with related compounds such as 2-FMA and 3-FA. Very little data exists about the pharmacological properties, metabolism, and toxicity of 4-FA, and it has only a brief history of human usage. Due to its strong psychostimulant effects, likely habit-forming properties as well as poorly understood toxicity profile, it is strongly recommended that one use proper harm reduction practices if choosing to use this substance.
- 1 Chemistry
- 2 Pharmacology
- 3 Subjective effects
- 4 Toxicity and harm potential
- 5 Legality
- 6 See also
- 7 External links
- 8 References
4-Fluoroamphetamine (4-FA) is a synthetic molecule of the amphetamine family. Molecules of the amphetamine class contain a phenethylamine core featuring a phenyl ring bound to an amino (NH2) group through an ethyl chain with an additional methyl substitution at Rα. Amphetamines are alpha-methylated phenethylamines. 4-fluoroamphetamine contains a fluorine atom at R4 of its phenyl ring and is a fluorinated analogue of amphetamine.
4-Fluoroamphetamine acts as a releasing agent and reuptake inhibitor of dopamine, serotonin, and norepinephrine producing stimulating amphetamine-like effects at lower doses and euphoric, entactogenic effects similar to MDMA at dosages above 100mg. The mechanism of action of 4-FA effectively boosts the levels of the norepinephrine, dopamine, and serotonin neurotransmitters in higher doses in the brain by binding to and partially blocking the transporter proteins that normally remove those monoamines from the synaptic cleft. This allows dopamine, norepinephrine, and serotonin to accumulate within the brain, resulting in stimulating, euphoric and entactogenic effects.
It is commonly reported that the first three to four hours of 4-FA present distinct entactogenic effects that have been reported as feeling somewhat similar to MDMA although not quite as powerful. This is thought to correlate with the duration in which it is promoting the release of serotonin (in addition to dopamine and norepinephrine). After this first phase of the experience, the effect then shifts towards something which feels like classic amphetamine stimulation which can persist for an extended period.
Do not use 4-FA if you have a history of heart-related issues or experience a severe headache after its use. We have been made aware of a report released by Trimbos-instituut and Nationaal Vergiftigingen Informatie Centrum (NVIC), describing incidents of strokes after an increased use of 4-FA. In addition to the common amphetamine-like effects (agitation, anxiety, tachycardia, hypertension, chest pain et al.), serious cardio- and cerebrovascular complications have been reported, including rhythm (sinus arrhythmia, ventricular extrasystoles (bigeminy), conduction disturbances) and acute cardiac failure. Although a causal relationship has not been confirmed, when presented with a severe headache and lateralization after 4-FA usage, a medical evaluation at an emergency department should be conducted immediately. 
The effects listed below are based upon the subjective effects index and personal experiences of PsychonautWiki contributors. The listed effects should be taken with a grain of salt and will rarely (if ever) occur all at once, but heavier doses will increase the chances and are more likely to induce a full range of effects. Likewise, adverse effects become much more likely on higher doses and may include serious injury or death.
- Sedation & Stimulation - The first few hours of the 4-FA experience are commonly reported to have overtones of the type of sedation that is associated with the serotonin-releasing properties of entactogens like MDMA. After these entactogenic effects fade and the stimulating effects become predominant. The stimulation which 4-FA produces throughout the entirety of the experience be described as being slightly weaker in intensity to amphetamine and less forceful than traditional dopaminergic stimulants such as cocaine.
- Spontaneous physical sensations - The "body high" of 4-FA can be characterized as a moderate to extreme euphoric tingling sensation that encompasses the entire body. It is capable of becoming overwhelmingly pleasurable at higher doses. This sensation maintains a consistent presence that steadily rises with the onset and hits its limit once the peak has been reached.
- Physical euphoria - This effect is extremely intense when compared to its physical stimulation.
- Tactile enhancement
- Bodily control enhancement
- Stamina enhancement
- Temperature regulation suppression
- Abnormal heartbeat
- Increased heart rate
- Increased blood pressure
- Vibrating vision - At high doses, a person's eyeballs may begin to spontaneously wiggle back and forth in a rapid motion, causing the vision to become blurry and temporarily out of focus. This is a condition known as nystagmus and is considered to be harmless in most cases.
- Muscle contractions
- Appetite suppression
- Dry mouth
- Increased perspiration
- Pupil dilation
- Orgasm suppression
- Temporary erectile dysfunction
- Teeth grinding
- Seizure - This is a rare effect but is thought to be able to occur in those predisposed to them, especially when taking heavier-than-recommended doses or redosing while in physically taxing conditions such as being dehydrated, fatigued, undernourished, or overheated.
- Anxiety suppression
- Empathy, affection, and sociability enhancement - In comparison to other substances, this effect can be described as identical to the effects produced by MDMA, but with less intensity. Like euphoria, it is most present at dosages above 100mg.
- Cognitive euphoria - This effect can be described in its manifestation as a series of euphoric waves that recede and reappear randomly throughout the experience. It is most present at dosages above 100mg.
- Thought acceleration
- Focus enhancement
- Novelty enhancement
- Immersion enhancement
- Motivation enhancement
- Increased music appreciation
- Increased sense of humor
- Compulsive redosing
- Increased libido
- Delirium & Confusion - This effect typically only occurs with overly high doses, and is associated with temperature dysregulation and overheating, particularly when 4-FA is taken in crowded, physically strenuous environments that leaves the user unable to cool off, rest, or rehydrate adequately.
- Ego inflation
- Time distortion - This can be described as the experience of time speeding up and passing much quicker than it usually would when sober.
- Unity and interconnectedness - Experiences of unity, oneness, and interconnectedness are sometimes reported with 4-FA. This component most consistently manifests itself at higher doses during the empathogenic phase, within large crowds at raves and musical events in the form of "becoming one with the crowd." Music is said to intensify this effect as well consistently.
The effects which occur during the offset of a stimulant experience generally feel negative and uncomfortable in comparison to the effects which occurred during its peak. This is often referred to as a "comedown" and occurs because of neurotransmitter depletion. Its effects commonly include:
- Brain zaps
- Cognitive fatigue
- Sleep paralysis - Some users report a higher incidence of experiencing sleep paralysis after consuming 4-FA, usually only at higher doses.
- Motivation suppression
- Thought deceleration
- Thought disorganization
- Suicidal ideation - This effect is typically only reported when 4-FA is misused by either taking it too frequently, with excessive doses, and/or compulsively.
Anecdotal reports which describe the effects of this compound within our experience index include:
- Experience:120mg/170mg 4-FA - Substance Overview
- Experience:500mg 4-FA + 150mg 5-HTP - Irresponsible & unexpected psychedelic
Additional experience reports can be found here:
Toxicity and harm potential
The toxicity and long-term effects of recreational 4-FA use have only scarcely been studied because 4-FA has very little history of human usage. Anecdotal evidence, as well as several case reports, suggest there is a small to moderate individual health risk associated with the use of 4-FA. Among these, it appears there is an especially a high risk for acute cardiovascular toxicity. Some people in the Netherlands, only using a moderate dose, have died due to cardiac arrest or suffered severe brain damage due to a stroke. The mechanism of this acute toxicity is not yet known, but it seems as though the stroke starts off as an intense headache or even a migraine attack, that slowly worsens.
It is also worth noting that 4-FA is particularly caustic in comparison to other compounds and can, therefore, cause chemical burns within the nasal passage and throat if it is insufflated. This method of administration is discouraged.
It is strongly recommended that one use harm reduction practices when using this substance.
Tolerance and addiction potential
As with other stimulants, the chronic use of 4-FA can be considered moderately addictive with a high potential for abuse and is capable of causing psychological dependence among certain users. When addiction has developed, cravings and withdrawal effects may occur if a person suddenly stops their usage.
Tolerance to many of the effects of 4-FA develops with prolonged and repeated use. This results in users having to administer increasingly large doses to achieve the same effects. After that, it takes about 3 - 7 days for the tolerance to be reduced to half and 1 - 2 weeks to be back at baseline (in the absence of further consumption). This is how long it takes to reduce the tolerance for the stimulating effects. Tolerance for the entactogenic effects may take a longer period to reduce. 4-FA presents cross-tolerance with all dopaminergic stimulants, meaning that after the consumption of 4-FA all stimulants will have a reduced effect.
4-FA, like other stimulants, can result in a stimulant psychosis that may present with a variety of symptoms (e.g., paranoia, hallucinations, or delusions). A review on treatment for amphetamine, dextroamphetamine, and methamphetamine abuse-induced psychosis states that about 5–15% of users fail to recover completely. The same review asserts that, based upon at least one trial, antipsychotic medications effectively resolve the symptoms of acute amphetamine psychosis.
Although many psychoactive substances are safe to use on their own, they can become dangerous or even life-threatening when taken with other substances. The list below contains some potentially dangerous combinations, but may not include all of them. Certain combinations may be safe in low doses but still increase the possibility of injury of death. Independent research should always be conducted to ensure that a combination of two or more substances is safe before consumption.
- Stimulants - 4-FA can be potentially dangerous in combination with other stimulants as it can increase one's heart rate and blood pressure to dangerous levels.
- 25x-NBOMe/25x-NBOH - Members of the 25x family are highly stimulating and physically straining. Combinations with stimulants should be avoided due to the risk of excessive stimulation. This can result in panic attacks, thought loops, seizures, increased blood pressure, vasoconstriction, and heart failure in extreme cases.
- Alcohol - Alcohol can be dangerous to combine with stimulants due to the risk of accidental over-intoxication. Stimulants mask the sedative effects of alcohol, which is the main factor people use to assess their degree of intoxication. Once the stimulant wears off, the depressant effects of alcohol are left unopposed, which can result in blackouts and respiratory depression. If combined, one should strictly limit themselves to only drinking a certain amount of alcohol per hour.
- DXM - Combinations with DXM should be strictly avoided due to DXM's effects on serotonin and dopamine reuptake. This can lead to panic attacks, hypertensive crisis, or serotonin syndrome.
- MXE - Combinations with MXE may dangerously elevate blood pressure and increase the risk of psychosis.
- Tramadol - Tramadol lowers the seizure threshold. Combinations with stimulants may further increase this risk.
- MDMA - The neurotoxic effects of MDMA may be increased when combined with other stimulants.
- Cocaine - This combination may increase strain on the heart to dangerous levels.
Serotonin syndrome risk
Combinations with the following substances can cause dangerously high serotonin levels. Serotonin syndrome requires immediate medical attention and can be fatal if left untreated.
- MAOIs such as syrian rue, banisteriopsis caapi, 2C-T-2, 2C-T-7, αMT, and some antidepressants
- Serotonin releasers such as MDMA, 4-FA, methylone and αMT
- Selective serotonin re-uptake inhibitors (SSRIs)
- Serotonin-norepinephrine reuptake inhibitors (SNRIs) such as tramadol and DXM
This legality section is a stub.
As such, it may contain incomplete or wrong information. You can help by expanding it.
- Arizona: The drug was added to the "Dangerous Drug" list in April 2014.
- Austria: 4-FA is illegal to possess, produce and sell under the NPSG (Neue-Psychoaktive-Substanzen-Gesetz Österreich).
- Louisiana: 4-FA is currently listed as a Schedule I drug as of June 2013.
- Virginia: The drug is classified as a Schedule I drug.
- Brazil - Possession, production and sale is illegal as it is listed on Portaria SVS/MS nº 344.
- Germany: 4-fluoroamphetamine was added to "Anlage I" in January 2012.
- Hungary: In January 2012, 4-flouroamphetamine became controlled in Hungary.
- France: 4-fluoroamphetamine was added to the list of illicit substances in March 2011.
- Israel: In December 2007, 4-flouroamphetamine was added to Israel's list of controlled substances, making it illegal to buy, sell, or possess.
- Poland: 4-Fluoroamphetamine is controlled in Poland.
- Slovak Republic: Beginning March 1, 2011, 4-Fluoroamphetamine is controlled in the Slovak Republic.
- United Kingdom: 4-FA is considered a Class A drug as a result of the amphetamine analogue clause of the Misuse of Drugs Act 1971.
- New Zealand: 4-FA is an amphetamine analogue, so is a Schedule 3 controlled substance in New Zealand.
- The Netherlands: 4-FA is, as of May 25th 2017, a Schedule 1 drug in the Netherlands. 
- Canada: 4-FA would fall under Schedule I as it is considered an analog of amphetamine.
- Quednow, B., Girreser, U., Junge, T., & Ro, P. (2005). Isomeric Fluoro-methoxy-phenylalkylamines: a new series of controlled-substance analogues (designer drugs), 148, 143–156. https://doi.org/10.1016/j.forsciint.2004.05.003
- The effects of non-medically used psychoactive drugs on monoamine neurotransmission in rat brain (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/17223101
- Isomeric fluoro-methoxy-phenylalkylamines: a new series of controlled substance analogues (designer drugs). (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/15639609
- http://www.sciencedirect.com/science/article/pii/0028390875900994 | Comparison of 4-chloro-, 4-bromo-and 4-fluoroamphetamine in rats: drug levels in brain and effects on brain serotonin metabolism
- http://www.sciencedirect.com/science/article/pii/S0014299906013811 | The effects of non-medically used psychoactive drugs on monoamine neurotransmission in rat brain
- E. Costa and S. Garattini (1970). Amphetamines and Related Compounds. New York: Raven Press. p. 28.
- Shoptaw, S. J., Kao, U., & Ling, W. (2009). Treatment for amphetamine psychosis. The Cochrane Library.
- Hofmann FG (1983). A Handbook on Drug and Alcohol Abuse: The Biomedical Aspects (2nd ed.). New York: Oxford University Press. p. 329. ISBN 9780195030570.
- Talaie, H., Panahandeh, R., Fayaznouri, M. R., Asadi, Z., & Abdollahi, M. (2009). Dose-independent occurrence of seizure with tramadol. Journal of Medical Toxicology, 5(2), 63-67. https://doi.org/10.1007/BF03161089
- Gillman, P. K. (2005). Monoamine oxidase inhibitors, opioid analgesics and serotonin toxicity. British Journal of Anaesthesia, 95(4), 434-441. https://doi.org/10.1093/bja/aei210
- Misuse of Drugs Act 1971 (Legislation.gov.uk) |http://www.legislation.gov.uk/ukpga/1971/38/schedule/2/part/I
- Controlled Drugs and Substances Act (S.C. 1996, c. 19) | http://laws-lois.justice.gc.ca/eng/acts/C-38.8/page-12.html#h-28