Fenethylline Facts
Stimulant;
Description
Fenethylline — also known as Captagon — is a synthetic stimulant of the substituted amphetamine class. It boosts dopamine and norepinephrine while blocking adenosine receptors, producing both stimulant arousal and extended wakefulness.[1]
Subjective effects include stimulation, wakefulness, cognitive euphoria, appetite suppression, and heightened focus. The experience is smoother than pure amphetamine — a steady, even alertness with less jitteriness and a prolonged wakefulness from the theophylline component.
Fenethylline carries real dependence potential driven by its amphetamine metabolite; no human death has been directly attributed to the genuine compound.[2] Cardiovascular risks at abuse doses are serious: heart attack[3] and life-threatening rhythm changes[4] have been documented.
Dose and durationby route · individual sensitivity varies
Starts in 90 – 120 minLasts 3 – 4 hoursAfter-effects 2 – 6 hours
Body and dependence
- Acute toxicity
- Moderate
- Chronic toxicity
- Moderate
- Physical dependence
- Low
- Psychological dependence
- Moderate
- Withdrawal
- Moderate
- Compulsive redosing
- Moderate
Tolerance
- Builds
- Moderate
- Fully resets after
- 14 days
- Carries over to
- amphetamine;
methamphetamine; other amphetamine-type stimulants
Effectslikely at a common dose
- Perception
- none likely · 2 possible
- Body
- Appetite suppression;
Stimulation; Wakefulness; +20 possible, including Heart rate perception changes, Insomnia, Vasoconstriction - Thinking
- none likely · 14 possible, including Compulsive redosing urge
- Feeling
- none likely · 8 possible, including Anxiety, Anhedonia, Depression
- Self
- none likely · 7 possible, including Craving, Ego inflation
- Awareness
- none likely · 1 possible
Who shouldn't take it
Combinations62 recorded
Seek help immediately if
- Chest pain; racing, pounding, or irregular heartbeat
- Very high body temperature; heavy sweating; hot, flushed skin
- Severe agitation, paranoia, panic, or confusion
- Severe headache; muscle rigidity or twitching
- Seizures
- Signs of stroke — face drooping, one-sided weakness, slurred speech
- Difficulty breathing; collapse or unconsciousness
What to do
- Call emergency services for chest pain, overheating, seizure, or unresponsiveness
- Move them to a cool, quiet place and reduce stimulation
- Cool the body — remove excess clothing, apply cool damp cloths, fan them
- Keep them calm; reassure — panic worsens the cardiovascular strain
- If seizing, protect from injury (don't restrain); recovery position afterward
- Monitor breathing and be ready to give rescue breaths / CPR
Most stimulant overdoses settle with cooling, a calm environment, and time. The medical danger is hyperthermia, cardiac events (arrhythmia, heart attack, stroke), and seizures — get help immediately if any appear.
988 Suicide & Crisis LifelineFireside Project: 62-FIRESIDE
References
- [1]^Wu N, Feng Z, He X, Kwon W, Wang J, Xie XQ (2019) Insight of Captagon Abuse by Chemogenomics Knowledgebase-guided Systems Pharmacology Target Mapping Analyses — Scientific Reports doi:10.1038/s41598-018-35449-6
- [2]^Pergolizzi J, LeQuang JAK, Vortsman E, Magnusson P, El-Tallawy SN, Wagner M, Salah R, Varrassi G (2024) The Emergence of the Old Drug Captagon as a New Illicit Drug: A Narrative Review — Cureus doi:10.7759/cureus.55053
- [3]^Gokdemir MT, Giden R (2019) Acute inferior myocardial infarction associated with the ingestion of captagon pills: A case report — Turkish Journal of Emergency Medicine doi:10.1016/j.tjem.2018.05.001
- [4]^Gul EE, Gamal G, Ghazni MS, Al Nozha F (2023) Captagon-induced Brugada phenocopy: A report of two cases — Journal of Electrocardiology doi:10.1016/j.jelectrocard.2023.03.002