Aeruginascin, also known as 4-phosphoryloxy-N,N,N-trimethyltryptamine (4-PO-TMT), is an indoleamine derivative which occurs naturally within the mushrooms Inocybe aeruginascens,[1][2][3][4][5][6] Pholiotina cyanopus,[6] and Psilocybe cubensis.

It is closely related to the frog skin toxin bufotenidine (5-HTQ), a potent serotonin 5-HT3 receptor agonist, but the aeruginascin metabolite 4-HO-TMT (thought to be its active form) shows strong binding at the serotonin 5-HT2 receptors similar to psilocin.

[15] Unlike psilocybin, but similarly to 4-HO-TMT, aeruginascin does not produce the head-twitch response in rodents.

[17] The first scientific literature about the pharmacological effects of aeruginascin is from a study published by Gartz in 1989.

[19][20] This is in contrast to the slight and in some cases extremely dysphoric experiences reported from the accidental ingestion of non-aeruginascin-containing mushrooms (containing solely psilocybin and psilocin).