Norpsilocin

Norpsilocin, also known as 4-hydroxy-N-methyltryptamine (4-HO-NMT), is a tryptamine alkaloid recently discovered in 2017 in the psychedelic mushroom Psilocybe cubensis.^[1][2] It is hypothesized to be a dephosphorylated metabolite of baeocystin.^[2]

Norpsilocin

Clinical data
Other names	4-HO-NMT; 4-OH-NMT; 4-HO-MMT; 4-OH-MMT; 4-Hydroxy-NMT; 4-Hydroxy-MMT; 4-Hydroxy-N-methyltryptamine; 4-Hydroxy-mono-methyltryptamine; N-Desmethylpsilocin; Desmethylpsilocin; AS-63499; PLZ-1017; PLZ1017
Identifiers
IUPAC name 3-[2-(methylamino)ethyl]-1H-indol-4-ol
CAS Number	28363-70-4
PubChem CID	14107683
ChemSpider	27283888
UNII	TL6QDJ5TMQ
ChEMBL	ChEMBL4648350
CompTox Dashboard (EPA)	DTXSID901336988
Chemical and physical data
Formula	C11H14N2O
Molar mass	190.246 g·mol−1
3D model (JSmol)	Interactive image
SMILES CNCCC1=CNC2=C1C(=CC=C2)O
InChI InChI=1S/C11H14N2O/c1-12-6-5-8-7-13-9-3-2-4-10(14)11(8)9/h2-4,7,12-14H,5-6H2,1H3 Key:MTJOWJUQGYWRHT-UHFFFAOYSA-N

Norpsilocin was found to be a near full agonist of the 5-HT_2A receptor and was found to be more potent than psilocin.^[3][4] It also has affinity for other serotonin receptors.^[5] Moreover, it has been found to cross the blood–brain barrier in animals and to have good metabolic stability similarly to psilocin.^[5]

Norpsilocin has shown psilocin-related peripheral effects in animals, including decreased spinal reflexes such as knee jerk response (opposite effect to psilocin), antiserotonergic activity (14% of that of psilocin), and pressor activity (70% of that of psilocin).^[6][7] Surprisingly however, in spite of its serotonin 5-HT_2A receptor agonism and psilocin-like effects, norpsilocin failed to induce the head-twitch response, a behavioral proxy of psychedelic effects, in animals.^[5] Likewise, norbaeocystin and aeruginascin failed to induce the head-twitch response.^[5] Only psilocybin was effective in this regard.^[5] In any case, norbaeocystin showed antidepressant-like activity (forced swim test) similarly to psilocybin and fluoxetine in spite of its putative non-hallucinogenic nature.^[5] Norpsilocin itself was not tested in this assay.^[5]

A 2025 animal study found that both baeocystin and norpsilocin are peripherally selective with very limited ability to cross the blood–brain barrier.^[8]

Norpsilocin is being evaluated under the developmental code name PLZ-1017 for the possible treatment of pervasive developmental disorders in children.^[9]

See also

• 4-HO-NALT
• 4-Hydroxytryptamine