spec sheet10 rows
4-FA is amphetamine with a fluorine at the para (4) position of the ring, which shifts its character toward a hybrid of stimulant and mild entactogen. It releases dopamine, norepinephrine, and a meaningful amount of serotonin, so people describe an amphetamine-like push with some MDMA-like warmth. It is notable for a real, documented risk of sudden cardiovascular events, so it deserves particular caution.
- Stimulation and energy
- Mild empathogenic warmth
- Elevated mood
- Sudden severe headache
- Dangerous blood pressure spikes
- Stroke and cardiac risk
- Overheating
Mechanism
4-FA is a substituted amphetamine that acts as a releasing agent at the , , and transporters; the para-fluoro position boosts serotonin release relative to the meta isomer, giving the entactogen-like tint. The strong norepinephrine and serotonin activity together drive both the stimulation and the cardiovascular load. Its combined push on multiple monoamines underlies both its appeal and its danger.
receptor fingerprint
transporter (NET)Releaser
transporter (SERT)Releaser
()Releaser
Safetyrisks and cautions, not medical advice
4-FA has been linked to sudden severe headaches, dangerously high blood pressure, cardiac events, and hemorrhagic stroke (bleeding in the brain), which has made it a recognized public-health concern in places where it became popular. Its serotonin release makes MAOIs and other serotonergic drugs a serotonin-toxicity hazard, and overheating is a real risk in warm, high-activity settings. A sudden intense headache during use is a warning sign to take seriously. Not medical advice.
Subjective profileweighing the evidence above
Avoid this one. It has a documented pattern of sudden severe headache, dangerous blood pressure spikes and hemorrhagic stroke, enough to become a public-health concern where it caught on. A sudden intense headache on it is an emergency, not a side effect to ride out.
Resources
This entry is here for reference.
Research
- 1.Fatalities, Cerebral Hemorrhage, and Severe Cardiovascular Toxicity After Exposure to the New Psychoactive Substance 4-Fluoroamphetamine: A Prospective Cohort Study
- 2.Pharmacology of MDMA- and Amphetamine-Like New Psychoactive Substances
2 listed here; entry last updated August 2026
Reviews
My notesprivate to this device
FAQ
Why is 4-FA considered especially risky?
It has been tied to sudden cardiovascular events including hemorrhagic stroke, sometimes signalled by an abrupt severe headache during use.
Is it like MDMA?
Partly; its serotonin release gives some MDMA-like warmth, but it is more stimulant-heavy and carries its own cardiovascular dangers.
What should not be combined with it?
MAOIs and other serotonergic drugs risk serotonin toxicity, and other stimulants stack cardiovascular strain.
Adverse effects
- Sudden severe headache
- Dangerous blood pressure spikes
- Stroke and cardiac risk
- Overheating