4-Acetoxy-DET  (4-Acetoxy-N,N-diethyltryptamine),  also known as ethacetin,  ethylacybin or 4-AcO-DET is a psychedelic tryptamine.  It was first synthesized in 1958 by Albert Hofmann in the Sandoz lab.  4-AcO-DET is an obscure synthetic psychedelic tryptamine.  Today it is either used recreationally as a designer drug or as an entheogenic compound.

4-AcO-DET is the acetylated form of 4-HO-DET  (also known as ethocin)  and is a higher homolog of 4-AcO-DMT and 4-AcO-MET.  Like the aforementioned compounds,  it is commonly hypothesized to act principally as a prodrug for their respective hydrolyzed counterparts  (e.g. 4-HO-DMT, 4-HO-MET and 4-HO-DET).  4-Acetoxy-DET is orally active,  and dosages of 10–25 mg are common.  Effects last 4–6 hours.  The free base is also active when smoked in a dose range of 5–20 mg.  Smoking 4-acetoxy-DET greatly speeds up the onset;  peak effects are experienced within 10 minutes,  and are usually over within 1 hour.