Fenethylline

Fenethylline (BAN, USAN) or fenetylline (INN) is a codrug of amphetamine and theophylline and so a mutual prodrug of both. It is also spelled phenethylline; other names for it are amphetaminoethyltheophylline and amfetyline. The drug was marketed for use as a psychostimulant under the brand names Captagon, Biocapton, and Fitton. The brand name "Captagon" (or in lowercase as "captagon") is often used generically to describe illicitly produced fenethylline.

Fenethylline is now illegal in most countries. It is produced primarily for illicit use, which takes place mainly in the Middle East, with some evidence that it is used by Islamist militants and terrorists, as stimulants for gunmen. The illicit global market for the drug was estimated in 2023 to be worth approximately US$ 57 billion.

Smuggling of Captagon became Syria's principal export, exceeding the total of all other exports under the Assad regime, from 2011 to 2024 of the Syrian Civil War in which it ruled Syria. It was the world's largest producer of the drug, accounting for about 80% of the global supply. A huge quantity of "Captagon", ready for clandestine export, was captured by anti-Assad forces that took control of Damascus in December 2024.