Two more 'zombie vape' precursors added to controlled substances list

Taipei, Sept. 17 (CNA) Two more precursors used to produce the anesthetic etomidate, commonly found in electronic cigarettes known as "zombie vapes," have been designated Category 4 controlled substances amid growing public safety concerns, an official said Wednesday.

The designation of ethyl N-formyl-N-(1-phenylethyl)glycinate and etomidate acid as Category 4 controlled drug ingredients took effect Tuesday, according to Chang Chih-hsu (張志旭), deputy head of the Taiwan Food and Drug Administration's (TFDA) Division of Controlled Drugs.

Institutions possessing the substances must obtain a registration license, maintain daily inventory records, and submit regular reports, Chang told CNA.

Researchers must also obtain TFDA approval before using the substances, while their import, export, manufacture, purchase, sale, and use are now subject to strict regulation, he said.

Two other etomidate precursors, ethyl 1H-imidazole-5-carboxylate and 2-mercaptoetomidate, were previously designated Category 4 controlled substances.

The government's move comes amid a rapid rise in the use of etomidate-laced "zombie vapes" in Taiwan, which has raised serious public health and safety concerns.

The drug's anesthetic effects, which can include blackouts and involuntary muscle movements, can impair drivers' reflexes and have been linked to several fatal traffic accidents.

The number of illicit etomidate cases recorded in Taiwan surged from 22 in 2023, when the substance was first detected locally, to 2,779 in 2024 and 20,727 in 2025. A further 13,879 cases were recorded in the first half of 2026, according to government data.

Taiwan designated etomidate a Category 4 controlled drug in 2024 before upgrading it to a Category 1 illicit drug in June 2026.