4-FA
4-FA is a synthetic substituted amphetamine that produces a distinctive combination of stimulant and entactogenic effects. It became commercially available as a research chemical in the early 2000s and gained particular popularity in the Netherlands. Users commonly describe its effects as intermediate between amphetamine and MDMA1, with a moderate entactogenic onset that gradually transitions into traditional amphetamine-type stimulation. Very little data exists regarding its pharmacological properties, metabolism, and toxicity.
Contents
Dosage & Duration
Dosage
Lower doses within the common range are described as producing milder, more functional stimulation, while higher doses are associated with stronger recreational and entactogenic effects.
Duration
Subjective Effects
In comparison to other substituted amphetamines, 4-FA is particularly free of side effects such as nausea, high blood pressure, anxiety and an uncomfortable offset. In low doses, it is considered to be an extremely functional and effective nootropic for performing tasks or general productivity of any sort. At higher dosages, however, it becomes dysfunctional and recreational due to the intensity of its euphoria and stimulation.
Physical
Cognitive
Reagent Testing
Loading reagent data
Pharmacology
Pharmacodynamics
4-FA acts as a releasing agent and reuptake inhibitor of dopamine, serotonin, and norepinephrine.2 Its monoamine-releasing profile is most potent at the norepinephrine transporter (EC50 = 37 nM), followed by dopamine (EC50 = 200 nM) and serotonin (EC50 = 730 nM), with corresponding reuptake inhibition at each transporter.2 The substance also displays low affinity for serotonin 5-HT2A and 5-HT2C receptors2, very low-potency partial agonism at the 5-HT2B receptor, and weak inhibitory activity at monoamine oxidase A.2
Pharmacokinetics
The fluorine substituent at the 4-position of the phenyl ring is thought to resist metabolic deactivation by hepatic cytochrome P450 oxidase, distinguishing 4-FA from other haloamphetamines in its metabolic susceptibility.
Dangerous
Highest riskThese combinations are considered extremely harmful and should always be avoided. Reactions to these drugs taken in combination are highly unpredictable and have a potential to cause death.
Tolerance
Dopaminergic stimulants
Harm Potential
Addiction & Dependence
Psychological
ModerateChronic 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. Compulsive redosing is commonly reported. When addiction has developed, cravings and withdrawal effects may occur if a person suddenly stops their usage.
Physical
Withdrawal effects have been reported upon cessation of chronic use.
Toxicity
Acute cardiovascular toxicity appears to be an especially high risk with 4-FA, even at moderate doses; reported complications include arrhythmias (sinus arrhythmia, ventricular extrasystoles, conduction disturbances), acute cardiac failure, cardiomyopathy including reverse takotsubo syndrome, cerebral hemorrhage, and stroke.34 Some users in the Netherlands have died from cardiac arrest or suffered severe brain damage from stroke.3
Animal studies suggest 4-FA has relatively low potential for neurotoxicity compared to related halogenated amphetamines; it does not cause long-lasting depletion of brain serotonin, unlike its analogs 4-CA and 4-BA.6
4-FA is particularly caustic compared to other compounds and can cause chemical burns within the nasal passage and throat when insufflated.
One fatal case of extensive bowel ischemia has been reported following chronic 4-FA use.
Psychosis Risk
4-FA, like other stimulants, can result in stimulant psychosis that may present with paranoia, hallucinations, or delusions. Based on research on related amphetamines, approximately 5-15% of users who develop stimulant psychosis may fail to recover completely.7 Delirium and confusion typically only occur with overly high doses, particularly when combined with temperature dysregulation and overheating in physically strenuous environments. Antipsychotic medications have been shown to effectively resolve symptoms of acute amphetamine psychosis.7
Seizure Risk
Seizures are a rare effect but are 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.
History & Culture
Synthesis and Early Research
4-Fluoroamphetamine was first synthesized in the early 1940s,2 though no records exist of the compound being tested in humans for many years following its initial preparation. During the 1960s, researchers began investigating 4-FA alongside other
Legality
International
1961 Single Convention: 4-FA is not individually scheduled.
1971 Convention on Psychotropic Substances: Schedule II.
1988 Convention: 4-FA is not listed in precursor Tables I or II.
By Country
References
Source Pages
Citations
- Felix Linsen et al.. (2015). 4-Fluoroamphetamine in the Netherlands: more than a one-night stand. Addiction, 110(7), 1138-1143. https://doi.org/10.1111/add.129321234
- Brandt SD, Poovendran D, & Kershaw S. (2017). 4-Fluoroamphetamine (4-FA) Critical Review Report, Agenda Item 4.3. World Health Organization, Expert Committee on Drug Dependence, Thirty-ninth Meeting. https://researchonline.ljmu.ac.uk/id/eprint/7380/1/WHO_2017_CR_4.3_4-FA_Critical_Review.pdf12345678910111213
- Hondebrink L, Nugteren-van Lonkhuyzen JJ, Van Der Gouwe D, & Brunt TM. (2018). Fatalities, Cerebral Hemorrhage, and Severe Cardiovascular Toxicity After Exposure to the New Psychoactive Substance 4-Fluoroamphetamine: A Prospective Cohort Study. Annals of Emergency Medicine. https://doi.org/10.1016/j.annemergmed.2017.08.04112
- Bruggink AH, & Bruggink-André de la Porte PW. (2020). Acute onset heart failure due to reverse type Takotsubo cardiomyopathy caused by a single dose of 4-Fluoroamphetamine in a healthy young individual. HeartRhythm Case Reports. https://doi.org/10.1016/j.hrcr.2020.09.0151
- Bosma KA, Verschoor A, & Menting TP. (2014). Cardiogenic shock after use of fluoroamphetamine confirmed with serum and urine levels. BMJ Case Reports. https://doi.org/10.1136/bcr-2014-2043281
- (October 1975). Comparison of 4-chloro-, 4-bromo- and 4-fluoroamphetamine in rats: drug levels in brain and effects on brain serotonin metabolism. Neuropharmacology, 14(10), 739–746. https://doi.org/10.1016/0028-3908(75)90099-412
- Shoptaw SJ, Kao U, & Ling W. (2009). Treatment for amphetamine psychosis. Cochrane Database of Systematic Reviews. https://pmc.ncbi.nlm.nih.gov/articles/PMC7004251/12
- Hondebrink L, Nugteren-Van Lonkhuyzen JJ, Van Der Gouwe D, & Brunt TM. (2015). Monitoring new psychoactive substances (NPS) in The Netherlands: data from the drug market and the Poisons Information Centre. Drug and Alcohol Dependence, 147, 109-115. https://doi.org/10.1016/j.drugalcdep.2014.11.0331
- (25 May 2017). Het is nu officieel: de partydrug 4-FA is verboden. nos.nl. https://nos.nl/op3/artikel/2174904-het-is-nu-officieel-de-partydrug-4-fa-is-verboden.html12
- (2015-07-30). Resolução RDC nº 32, de 30 de julho de 2015 (Lista F2). ANVISA / Brazilian Government. https://www.gov.br/anvisa/pt-br/assuntos/medicamentos/controlados/lista-substancias1
- (n.d.). Controlled Drugs and Substances Act, Schedule III. laws-lois.justice.gc.ca. https://laws-lois.justice.gc.ca/eng/acts/C-38.8/page-17.html1
- (n.d.). FINLEX ® - Ajantasainen lainsäädäntö: Valtioneuvoston asetus huumausaineina… 543/2008. https://finlex.fi/fi/lainsaadanto/2008/5431
- (n.d.). Arrêté du 22 février 1990 fixant la liste des substances classées comme stupéfiants (as amended). Légifrance / French Government. https://www.legifrance.gouv.fr/loda/id/JORFTEXT0000005330851
- (2019). Anlage I BtMG. https://www.gesetze-im-internet.de/btmg_1981/anlage_i.html1
- (n.d.). Misuse of Drugs Act 1975, Schedule 3 Class C controlled drugs (New Zealand). New Zealand Parliamentary Counsel Office. https://www.legislation.govt.nz/act/public/1975/0116/latest/DLM436723.html1
- (n.d.). Misuse of Drugs Act 1971; Misuse of Drugs Regulations 2001. gov.uk. https://www.gov.uk/government/publications/controlled-drugs-list--2/list-of-most-commonly-encountered-drugs-currently-controlled-under-the-misuse-of-drugs-legislation1
- (n.d.). 21 CFR § 1308.11(d). ecfr.gov. https://www.ecfr.gov/current/title-21/chapter-II/part-1308/section-1308.111
Further Reading
4-FA vs MDMA cardiovascular study (J Psychopharmacol 2022)
Drug-induced serotonin syndrome (U.S. Pharmacist 2010)
Drugs-Forum: 4-FA experiences thread
Dutch Health Institute alert on 4-FA risks (RIVM 2017)
Jellinek Institute 4-FA factsheet- PubChem: 4-Fluoroamphetamine
- Safety and neurocognition after acute 4-FA (Front Pharmacol 2018)
Automated synthesisInformation aggregated and synthesized using an autonomous workflow built by Josie Kins.
Suggest an edit
Spotted a mistake, an outdated claim, or something missing from the 4-FA article? Send the editors a private note. Feedback lands in a moderation queue and is never shown on the site.