4-HO-pyr-T
4-HO-pyr-T, also known as 4-hydroxy-N,N-tetramethylenetryptamine, is a serotonin receptor modulator of the tryptamine, 4-hydroxytryptamine, and pyrrolidinylethylindole families. It is the 4-hydroxyl analogue of pyr-T and the analogue of psilocin (4-HO-DMT) and 4-HO-DET in which the N,N-dialkyl moiety has been cyclized into a pyrrolidine ring.