Norpsilocin is to baeocystin what psilocin is to psilocybin: the same molecule without its phosphate group (Sherwood et al., 2020). It has one methyl group on its side-chain nitrogen where psilocin has two. It is one of the tryptamines lab studies now measure in psilocybin mushrooms (Cohen et al., 2025).
It drew attention because of a mismatch. In a 2020 study, norpsilocin was a potent 5-HT2A agonist in cell assays, yet baeocystin, its likely parent, produced no head twitches in mice (Sherwood et al., 2020). A 2025 rat study offers a reason: baeocystin and norpsilocin had a very limited ability to cross the blood-brain barrier (Danda et al., 2025).
How much baeocystin the body turns into norpsilocin, and whether any reaches the brain when swallowed with psilocybin, has not been measured. A 2025 feature reports that researchers who have studied these compounds, including the chemist who first identified norpsilocin in mushrooms, doubt they add much to a mushroom’s effects (Johnson-Groh, 2025). No human study has tested it.
Sources
- Sherwood et al., 2020, Journal of Natural Products
- Danda et al., 2025, Progress in Neuro-Psychopharmacology & Biological Psychiatry
- Johnson-Groh, 2025, ACS Central Science feature
- Cohen et al., 2025, Scientific Reports
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