Mycelium is the main body of a fungus: a network of thin threads called hyphae that grows through soil, wood or other material. Most of a fungus’s life is spent as mycelium. A mushroom is a different structure, the fruiting body, which the mycelium builds to release spores. Packed, hardened mycelium with nutrient reserves forms sclerotia (Wang et al., 2025).
Psilocybin is found in mycelium as well as in mushrooms. In 1959 Albert Hofmann and colleagues reported psilocybin and psilocin in fruit bodies, lab-grown mycelium and sclerotia of Psilocybe mexicana (Hofmann et al., 1959). A 2023 study found that fruiting bodies preferentially accumulated psilocybin compared with mycelium grown in the lab (Waldbillig et al., 2023).
In Canadian law the structure makes no difference. The Controlled Drugs and Substances Act lists psilocybin and psilocin, and section 2(2) extends that to any substance containing them. This entry is general information, not legal advice, and it describes no growing method.
Sources
- Wang et al., 2025, Frontiers in Microbiology
- Hofmann et al., 1959, Helvetica Chimica Acta
- Waldbillig et al., 2023, Frontiers in Fungal Biology
- Controlled Drugs and Substances Act (Justice Laws)
Last checked .