Where to buy 4-FA for sale online

One must exercise extreme caution and discernment when purchasing the designer drug 4-FA (4-Fluoroamphetamine). The online market for research chemicals is rife with sellers and vendors offering 4-FA for sale, but the risks associated with these transactions are significant.
One of the primary concerns with purchasing 4-FA online is the lack of regulation and oversight. Many of these vendors market 4-FA as a “research chemical” to circumvent drug laws, raising ethical questions about their intentions. It is essential to be aware that 4-FA is a potent psychoactive substance with effects similar to those of amphetamines and MDMA, and it has not been thoroughly studied for safety and efficacy in humans.
The quality and purity of 4-FA obtained from online sellers can be questionable. With stringent quality control measures in place, researchers and individuals who buy 4-FA avoid getting a product that is contaminated or of subpar quality, jeopardizing the integrity of any experiments or personal use.
Furthermore, the anonymity of online transactions makes it challenging to trace the origins of 4-FA sold by these vendors. This lack of transparency can be problematic, as it becomes difficult to identify the source of any adverse effects or potential misuse.
4-FA is often sold as a “party drug” or for recreational purposes, which raises concerns about its safety and legality. In some regions, it may be classified as a controlled substance, and purchasing it online could have legal consequences.


4-Fluoroamphetamine, also known as 4-FA or colloquially as Flux, represents a novel synthetic amphetamine compound. When administered, it elicits a distinctive blend of entactogenic and stimulant effects. It belongs to a series of amphetamine analogues that have been fluorinated, which initially included compounds like 2-FA, 2-FMA, and 3-FA.
Reports based on user experiences have characterized the subjective effects of 4-FA. These effects typically commence with a moderate, MDMA-like entactogenic onset during the initial few hours of the incident. This sensation gradually transitions into a more traditional amphetamine-type stimulation, resulting in a total duration of effects lasting around 6 to 8 hours. Some residual effects may linger a few hours after the primary experience
While 4-FA is not commonly found on the streets, it was once readily available in the grey area of research chemicals through online vendors. This availability often involved related compounds such as 2-FMA and 3-FA[1]. However, it is essential to note that there is limited data regarding the pharmacological properties, metabolism, and toxicity of 4-FA. Moreover, its history of human use is relatively brief.
Due to its potent psychostimulant effects, potential for habit formation, and poorly understood toxicity profile, it is strongly recommended that individuals exercise utmost caution and adhere to proper harm reduction practices if they choose to use this substance. Safety and responsible use should be paramount when dealing with compounds like 4-FA in research chemicals.

show IUPAC name
CAS Number459-02-9 
PubChem CID9986
CompTox Dashboard (EPA)DTXSID90894758 
Chemical and physical data
Molar mass153.200 g·mol−1


4-Fluoroamphetamine, often abbreviated as 4-FA, belongs to the synthetic amphetamine family. Within the amphetamine class of molecules, you’ll find a central phenethylamine core characterized by a phenyl ring connected to an amino (NH2) group through an ethyl chain, with an extra methyl substitution at Rα. These compounds are known as alpha-methylated phenethylamines. In the case of 4-fluoroamphetamine, it distinguishes itself by incorporating a fluorine atom at the R4 position of its phenyl ring, making it a fluorinated analogue of amphetamine.


4-Fluoroamphetamine, or 4-FA, operates as both a releasing agent and a reuptake inhibitor for dopamine, serotonin, and norepinephrine neurotransmitters. At lower doses, it induces stimulant effects akin to amphetamines, while at dosages exceeding 100mg, it can produce euphoric and entactogenic effects reminiscent of MDMA.
The mechanism of action of 4-FA involves enhancing the levels of these neurotransmitters—norepinephrine, dopamine, and serotonin—in the brain. It accomplishes this by binding to and partially impeding the transporter proteins responsible for clearing these monoamines from the synaptic cleft. Consequently, this inhibition allows dopamine, norepinephrine, and serotonin to accumulate within the brain, ultimately leading to stimulating, euphoric, and entactogenic effects.

Subjective effects

It is frequently reported that the initial three to four hours of 4-FA use exhibit distinct entactogenic effects, which have been likened to the sensation of MDMA, albeit slightly less potent. This is believed to coincide with the period during which it promotes the release of serotonin alongside dopamine and norepinephrine. Subsequently, the experience transitions into a more classic amphetamine-like stimulation, which can endure for an extended duration.

Caution should be exercised when considering 4-FA use if there is a history of heart-related problems or severe headaches after consumption. A report by Trimbos-instituut and Nationaal Vergiftigingen Informatie Centrum (NVIC) has brought to light incidents of strokes following increased 4-FA usage. Apart from common amphetamine-like effects such as agitation, anxiety, tachycardia, hypertension, and chest pain, serious cardio- and cerebrovascular complications have been documented, including irregular heart rhythms (sinus arrhythmia, ventricular extrasystoles), conduction issues, and acute cardiac failure. While a direct causal link has not been established, individuals experiencing severe headaches and lateralization after 4-FA use should seek immediate medical evaluation.

Disclaimer: The subsequent effects are based on anecdotal user reports and analyses from the Subjective Effect Index (SEI), an open research literature. They should be viewed with scepticism. These effects may only sometimes manifest, particularly in a predictable manner. Higher doses are more likely to induce the full range of products. Moreover, higher doses increase the risk of adverse effects, including addiction, severe injury, or even death.


  • Stimulation: The initial hours of a 4-FA experience often entail sedation reminiscent of serotonin-releasing entactogens like MDMA. As these entactogenic effects wane, stimulating effects become more prominent. The stimulation produced by 4-FA is generally milder in intensity than amphetamine and less forceful than traditional dopaminergic stimulants like cocaine.
  • Spontaneous bodily sensations: 4-FA’s “body high” is characterized by a moderate to intense euphoric tingling sensation enveloping the entire body. This sensation can become overwhelmingly pleasurable at higher doses and consistently intensifies throughout the experience.
  • Physical euphoria: 4-FA’s physical delight is notably intense, especially compared to its physical stimulation.
  • Tactile enhancement
  • Bodily control enhancement
  • Stamina enhancement
  • Temperature regulation suppression
  • Increased bodily temperature
  • Abnormal heartbeat
  • Increased heart rate
  • Increased blood pressure
  • Vibrating vision: At higher doses, individuals may experience rapid, involuntary eye movements (nystagmus), causing blurry and temporarily unfocused vision. This condition is generally harmless.
  • Headaches
  • Muscle contractions
  • Appetite suppression
  • Dehydration
  • Dry mouth
  • Increased perspiration
  • Pupil dilation
  • Orgasm suppression
  • Temporary erectile dysfunction
  • Difficulty urinating
  • Teeth grinding
  • Seizure: Though rare, seizures may occur in predisposed individuals, particularly with heavy or frequent dosing or when physically stressed due to dehydration, fatigue, undernourishment, or overheating.


  • Enhancements
  • Colour enhancement
  • Pattern recognition enhancement


  • Enhancements
  • Hallucinations
  • Distortions


  • Anxiety suppression
  • Disinhibition
  • Empathy, affection, and sociability enhancement: Similar to MDMA but with reduced intensity, particularly at dosages exceeding 100mg.
  • Cognitive euphoria: Manifests as sporadic euphoric waves throughout the experience, most pronounced at dosages exceeding 100mg.
  • Thought acceleration
  • Focus enhancement
  • Novelty enhancement
  • Immersion enhancement
  • Motivation enhancement
  • Increased music appreciation
  • Increased sense of humour
  • Compulsive redosing
  • Increased libido
  • Delirium & Confusion: Typically associated with excessively high doses, especially in situations with temperature regulation challenges and overheating, such as crowded and physically demanding environments.
  • Ego inflation
  • Time distortion: Perceived acceleration of time, passing more quickly than usual.


  • Unity and interconnectedness: Some users report experiences of unity, oneness, and interconnectedness, often occurring at higher doses during the empathogenic phase, especially in large crowds at events like raves, where individuals feel “becoming one with the crowd.” Music is said to intensify this effect consistently.


  • The offset of a stimulant experience is often characterized by negative and uncomfortable feelings compared to the peak effects. This is commonly referred to as a “comedown” resulting from neurotransmitter depletion. Effects may include:
    • Anxiety
    • Brain zaps
    • Headaches
    • Cognitive fatigue
    • Depression
    • Sleep paralysis (typically reported at higher doses)
    • Irritability
    • Motivation suppression
    • Thought deceleration
    • Thought disorganization
    • Suicidal ideation (typically associated with misuse, frequent dosing, or excessive amounts)
    • Wakefulness


Limited research has been conducted on the toxicity and long-term effects of recreational 4-FA use due to its relatively short history of human usage. Anecdotal evidence and several case reports suggest a small to moderate individual health risk associated with 4-FA use, with a notable emphasis on acute cardiovascular toxicity. Notably, individuals in the Netherlands have experienced cardiac arrest or severe brain damage following moderate 4-FA doses. The mechanism behind this acute toxicity remains unclear, but it often begins with an intense headache or migraine attack.

The LD50 (lethal dose for 50% of subjects) of 4-FA in mice via intraperitoneal injection is 46 mg/kg. Unlike MDMA or 4-FA’s analogues 4-CA and 4-BA, 4-FA does not lead to long-lasting depletion of brain serotonin.

It’s important to mention that 4-FA is notably acidic compared to other substances, which can result in chemical burns in the nasal passage and throat if insufflated. Therefore, this method of administration is discouraged.

The use of harm reduction practices is strongly recommended when using this substance.

Tolerance and Addiction Potential: 

Similar to other stimulants, chronic use of 4-FA can be moderately addictive, with a high potential for abuse and the possibility of psychological dependence in certain users. Individuals who develop addiction may experience cravings and withdrawal effects when discontinuing use. Tolerance to many of 4-FA’s products develops with prolonged and repeated use, necessitating larger doses to achieve the same impact. It takes approximately 3 – 7 days for tolerance to reduce by half and 1 – 2 weeks to return to baseline (without further consumption) for the stimulating effects. Tolerance to the entactogenic impact may take longer to reduce. Additionally, 4-FA presents cross-tolerance with all dopaminergic stimulants, meaning that other stimulants’ results will decrease after 4-FA consumption.


4-FA, like other stimulants, can induce stimulant psychosis, which may manifest with symptoms such as paranoia, hallucinations, or delusions. A review of treatment for amphetamine, dextroamphetamine, and methamphetamine abuse-induced psychosis indicates that approximately 5-15% of users may not fully recover. Antipsychotic medications have been found effective in resolving the symptoms of acute amphetamine psychosis.

Dangerous Interactions: 

Warning: Combining certain substances with 4-FA can be difficult or life-threatening. Some known dangerous interactions include:

  • Alcohol: Combining alcohol with stimulants like 4-FA can reduce the sedative effects of alcohol, leading to excessive drinking, increased risk of liver damage, and dehydration. It can also result in drinking beyond one’s usual limit, as the stimulant effects reduce the perception of drunkenness.
  • GHB/GBL: Stimulants can increase respiration rate, potentially allowing higher doses of sedatives like GHB/GBL. If the stimulant wears off first, the depressant effects of GHB/GBL may lead to respiratory arrest.
  • Opioids: Similar to GHB/GBL, stimulants increase respiration rate, allowing a higher dose of opioids. If the stimulant effects diminish before the opioids, respiratory arrest may occur.
  • Cocaine: Cocaine’s rewarding effects are mediated by dopamine transporters (DAT) inhibition, while amphetamine reverses DAT direction through a pH-mediated mechanism. Combining them can lead to cardiac impacts and increased risk of syncope due to turbulent blood flow during valve operation.
  • Cannabis: Stimulants can heighten anxiety levels, leading to thought loops and paranoia, potentially resulting in negative experiences when combined with cannabis.
  • Caffeine: Combining stimulants like 4-FA with caffeine is unnecessary and may strain the heart, potentially causing anxiety and physical discomfort.
  • Tramadol: Both substances can increase the risk of seizures.
  • DXM: Both substances raise heart rate, potentially leading to panic attacks and more severe heart issues.
  • Ketamine: Combining amphetamine and ketamine may result in psychoses resembling schizophrenia. This is due to the pharmacological effects of amphetamine on dopamine and ketamine’s NMDA antagonism effects.
  • PCP and Methoxetamine: Both substances increase the risk of tachycardia, hypertension, and manic states.
  • Psychedelics: Combining stimulants with psychedelics can increase the risk of anxiety, paranoia, and thought loops.
  • Various other substances: Some substances, such as 25x-NBOMe, 2C-T-x, 5-MeO-xxT, and others, may interact unfavourably with 4-FA, potentially leading to hypertensive crises or other adverse effects.
  • MAOIs: MAOIs can unpredictably increase the potency and duration of phenethylamines, with MAO-A inhibitors potentially causing hypertensive crises when combined with amphetamines.

Legal status

Austria: 4-FA is illegal to possess, produce, and sell under the Neue-Psychoaktive-Substanzen-Gesetz Österreich (NPSG).

Brazil: 4-FA is illegal to possess, produce, and sell as listed on Portaria SVS/MS nº 344.

Canada: 4-FA is classified under Schedule I due to its status as an analogue of amphetamine.

France: 4-FA was added to the list of illicit substances in March 2011.

Germany: 4-FA has been controlled under Anlage I BtMG (Narcotics Act, Schedule I) since July 26, 2012. Manufacturing, possessing, importing, exporting, buying, selling, procuring, or dispensing it without a license is illegal.

Hungary: 4-FA became controlled in Hungary in January 2012.

Israel: In December 2007, 4-FA was added to Israel’s list of controlled substances, making it illegal to buy, sell, or possess.

The Netherlands: 4-FA is classified as a Schedule 1 drug in the Netherlands as of May 25, 2017.

New Zealand: As an amphetamine analogue, 4-FA is categorized as a Schedule 3 controlled substance in New Zealand.

Poland: 4-FA is controlled in Poland.

Slovak Republic: Starting from March 1, 2011, 4-Fluoroamphetamine is controlled in the Slovak Republic.

Switzerland: 4-FA is a controlled substance listed explicitly under Verzeichnis D.

Turkey: 4-FA is classified as a drug and is illegal to possess, produce, supply, or import.

United Kingdom: 4-FA is considered a Class A drug due to the amphetamine analogue clause of the Misuse of Drugs Act 1971.

United States: 4-FA is not scheduled on a federal level in the United States.

State-Specific Regulations in the United States:

  • Arizona: 4-FA was added to the “Dangerous Drugs” list in April 2014.
  • Louisiana: 4-FA is listed as a Schedule I drug as of June 2013.
  • Virginia: 4-FA is classified as a Schedule I drug in Virginia.


1. What is 4-FA?

4-FA, or 4-Fluoroamphetamine, is a synthetic psychoactive substance chemically similar to amphetamine. It can produce stimulant and entactogenic effects, making it popular in certain recreational and party scenes.

2. Is 4-FA legal?

The legality of 4-FA varies from country to country and even within some regions or states. It is essential to check your local laws and regulations regarding 4-FA possession, use, and distribution.

3. What are the effects of 4-FA?

4-FA can produce various effects, including stimulation, increased sociability, euphoria, and sensory enhancement. Some users have reported experiences similar to MDMA, although milder.

4. What are the potential risks and side effects of 4-FA?

4-FA use may lead to adverse effects such as increased heart rate, elevated blood pressure, dehydration, anxiety, headaches, and, in severe cases, cardiovascular issues or psychosis. Long-term use can result in tolerance, addiction, and other health concerns.

5. Is 4-FA safe to use?

The safety of 4-FA is a subject of debate and concern. Due to limited research, its long-term effects and potential health risks still need to be fully understood. It is advisable to approach 4-FA use with caution and harm reduction strategies.

6. How is 4-FA typically consumed?

4-FA can be ingested orally, in capsule or powder form. Some users may also insufflate (snort) it, although this method is discouraged due to potential harm to the nasal passages and throat.

7. Is 4-FA addictive?

Like many stimulants, 4-FA has the potential to be psychologically addictive, and users may develop cravings with prolonged use. It is essential to be aware of the potential for addiction and exercise self-control.

8. Can 4-FA cause overdose?

While overdose cases involving 4-FA are relatively rare, excessive consumption can lead to severe health problems, including cardiovascular and psychological distress. It’s crucial to be mindful of dosage and use responsible harm-reduction practices.

9. Can 4-FA be used safely for therapeutic purposes?

There is limited evidence supporting the therapeutic use of 4-FA. Any use for medicinal purposes should be conducted under the guidance of a qualified medical professional and by local laws and regulations.

10. How can I reduce the risks associated with 4-FA use?

To minimize risks, consider the following:

  • Please educate yourself about 4-FA and its effects.
  • Start with a low dose to assess your tolerance.
  • Stay hydrated, but avoid excessive water intake.
  • Avoid combining 4-FA with other substances, especially alcohol.
  • Use with trusted friends in a safe environment.
  • Be mindful of your mental and physical well-being during and after use.
  • Seek professional help if you experience adverse effects or addiction.


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  20. Misuse of Drugs Act 1975 No 116 (as of 01 July 2022), Public Act – New Zealand Legislation.
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