4-Fluoroamphetamine 4-FA is a substituted amphetamine with stimulant, entactogenic and nootropic effects. It is described subjectively as being between amphetamine and MDMA. It is rarely found on the streets but commonly sold as a grey area research chemical through online vendors along with related compounds such as 2-fluoroamphetamine and 4-fluoromethamphetamine
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 flourine 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.
Studies demonstrate that 4-flourine amphetamine substitutions limit activity of the compound at the alpha-1 adrenergic receptor with an over 200-fold increased selectivity for A2 receptors over A1 receptors. It has also been demonstrated that 4-substitution of a hydrogen with fluorine on the aromatic ring of norepinephrine produces a beta-adrenergic agonist with little alpha activity.This has led the online community to speculate that the milder uncomfortable cognitive and/or physical side effects and greater efficacy as a nootropic associated with this substance are at least partially due to decreased activity at the alpha-1 adrenergic receptors resulting in significantly less norepinephrine reuptake inhibition.
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.
The first 4 – 5 hours of 4-FA present distinct entactogenia that feels somewhat similar to MDMA although not quite as powerful. After this first phase of the experience the sensation then shifts towards something which feels like extremely clean amphetamine.