Chemical Data
IUPAC: (RS)-1-(4-Fluorophenyl)propan-2-amine
CAS: 459-02-9
ChemSpider: 9592
Molecular Mass: 153.197
Molecular Formula: C9H12FN

4-FA Profile

4-FA is an acronym for 4-Fluoroamphetamine, a substituted amphetamine stimulant drug. It may also have entactogenic and nootropic qualities.

The chemical has the formal and systematic IUPAC name (RS)-1-(4-Fluorophenyl)propan-2-amine. It has an empirical formula of C9H12FN and molar mass of 153.2 grams.

4-FA is an analogue of amphetamine. As an amphetamine it has a phenethylamine backbone consisting of a phenyl ring bound to an amino (NH2) via an ethyl linkage with a methyl substitution at the carbon adjacent to the amino. Amphetamines are also called alpha methyl phenethylamines. The chemical distinguishes itself from normal amphetamine (speed) by having a fluorine atom substituted to the para position on the aryl ring.

The pharmacological action of the chemical is to release noradrenaline, serotonin and dopamine in to the synaptic cleft and then to prevent their reuptake out of the synapse. This results in an increased concentration of monoamine neurotransmitters in the synapses which hang around, activating receptors for a longer time. Monoamines are blocked from re-entering the neuron from which they are emitted as The chemical binds to the monoamine transport proteins and disrupts their action.

Unlike 4-CA and 4-BA, F-4A is not neurotoxic and does not cause long term depletion of serotonin in the brain. The chemical is not metabolised by the same route as the other haloamphetamines.

The chemical has an LD50 of 46 mg/Kg in mice. This is the dose required to kill 50% of the test animals. It has been involved in one death worldwide where it was taken in combination with methadone, benzodiazepine and other amphetamines.

The chemical is not for human or animal consumption.

A number of unverifiable online reports point to the subjective effects of 4-FA.

Compared to other substituted amphetamines 4-FA is free of many troubling side effects including anxiety, nausea, high blood pressure and troubling “come down”. It is reported as being an effective and highly functional nootropic at low doses and is used by some in these lower doses to increase productivity and focus for mundane tasks and for learning or studying.

At the higher reported doses 4-FA is not functional in this manner due to the high intensity of the stimulation and attendant euphoria.

Physical effects of 4-FA which have been reported online include enhancement of touch and physical euphoria. Feelings of physical euphoria are said to far outweigh physical stimulation. The stimulation by 4-FA in fact is said to be much weaker than amphetamine or dopamine stimulants like cocaine.

Negative or uncomfortable physical effects include grinding of teeth, sweating, elevated heart rate, dehydration and loss of appetite.

Cognitive euphoria is said to be present at doses exceeding 100 mg and comes in waves that rise and recede in an unpredictable fashion throughout the experience. It is said to produce feelings of love, sociability and empathy akin to the drug MDMA but of lower intensity.

The after effects include feelings of irritation, depression and anxiety. Also reported is an impairment in the ability to think clearly and a difficulty falling asleep.

The chemical may be habit forming and users will develop dependence if used frequently. All stimulants may induce psychosis if used over a prolonged period or at excessively high doses.

Other names and synonyms 

4-Fluoroamphetamine [Wiki]
1-(4-Fluorophenyl)-2-propanamine [ACD/IUPAC Name]
1-(4-Fluorophényl)-2-propanamine [French] [ACD/IUPAC Name]
1-(4-Fluorphenyl)-2-propanamin [German] [ACD/IUPAC Name]
Benzeneethanamine, 4-fluoro-α-methyl-
Benzeneethanamine, 4-fluoro-α-methyl- [ACD/Index Name]
Phenethylamine, p-fluoro-α-methyl-
120277-68-1 [RN]
377084-68-9 [RN]
459-01-8 [RN]
459-02-9 [RN]
Anisole, p-fluoro- (8CI)
Benzeneethanamine, p-fluoro-α-methyl- (9CI)
Phenethylamine, p-fluoro-α-methyl-