4-AcO-MET, also known as 4-acetoxy-N-methyl-N-ethyltryptamine or metacetin, is a psychedelic drug of the tryptamine family. It is the acetate ester of 4-HO-MET, and a homologue of 4-AcO-DMT. The drug is a novel compound with very little history of human use. It has been encountered as a novel designer drug.
4-AcO-MET is thought to be a prodrug of 4-HO-MET. The dose of 4-AcO-MET is said to be 5 to 40mg orally and its duration is said to be 4 to 10hours. It is said to produce psilocin (4-HO-DMT)-like psychedelic effects.
Due to its similarity to the psilocin prodrug 4-AcO-DMT, which is deacetylated to form psilocin in vivo, it is expected that 4-AcO-MET is also quickly hydrolyzed into 4-HO-MET by serum esterases, but human studies concerning the metabolic fate of this drug are lacking.
The pharmacology of 4-AcO-MET has been studied.
Analogues of 4-AcO-MET include methylethyltryptamine (MET), 4-HO-MET (metocin), 5-MeO-MET, 4-AcO-DMT (psilacetin), 4-AcO-DET (ethacetin), 4-AcO-MPT, and 4-PrO-MET, among others.
4-AcO-MET was encountered as a novel designer drug in Europe in 2009.
4-AcO-MET is not a controlled substance in Canada as of 2025.
In Switzerland, 4-AcO-MET is a controlled substance under Verzeichnis E.
In the United Kingdom, 4-AcO-MET is a Class A drug in the United Kingdom because it is an ester of the drug 4-HO-MET, which is a Class A drug under the tryptamine catch-all clause.
In the United States, 4-AcO-MET is not scheduled. It may be considered an analogue of psilocin, a Schedule I drug under the Controlled Substances Act. As such, the sale for human consumption or the use for illicit non-medical purposes could be considered a crime under the Federal Analogue Act.