Alkaline phosphatase is the body enzyme that turns psilocybin into psilocin. A 2017 review describes psilocybin as “primarily a pro-drug that is dephosphorylated by alkaline phosphatase to active metabolite psilocin” (Dinis-Oliveira, 2017). The step removes one phosphate group and leaves a hydroxyl in its place.
The conversion is fast. A 2025 systematic review of human and animal studies describes psilocybin as quickly converted to psilocin (Meshkat et al., 2025). In a 2017 study of 12 healthy adults, no psilocybin was found in plasma or urine, only psilocin and its products (Brown et al., 2017).
Alkaline phosphatases are a family of enzymes found in many tissues, and they are not specific to psilocybin. The mushroom has its own phosphate-removing enzyme, PsiP, which does the same job when its tissue is damaged and starts the blue bruising reaction (Lenz et al., 2020). How much individual differences in this step matter for a person’s response has not been worked out.
Sources
- Dinis-Oliveira, 2017, Drug Metabolism Reviews: metabolism of psilocybin and psilocin
- Meshkat et al., 2025, Pharmaceutics: pharmacokinetics of psilocybin, systematic review
- Brown et al., 2017, Clinical Pharmacokinetics: escalating oral psilocybin
- Lenz et al., 2020, Angewandte Chemie: the enzymes behind bluing
Last checked .