Definition
The Stamets Stack is a microdosing protocol developed by mycologist Paul Stamets that pairs a sub-perceptual dose of psilocybin mushrooms with Lion's Mane mushroom extract and niacin (vitamin B3). The stated rationale is that the combination may support neurogenesis and cognitive function more than psilocybin microdosing alone, though this combined-stack theory is less rigorously studied than psilocybin research on its own.
How the Stack Is Meant to Work
Each component of the stack is included for a different proposed reason. Psilocybin, at a microdose, is used for its potential mood and cognitive effects without a noticeably psychedelic experience. Lion's Mane (Hericium erinaceus) is a non-psychoactive medicinal mushroom studied for compounds — hericenones and erinacines — theorized to stimulate nerve growth factor (NGF) production, which is linked to neuroplasticity. Niacin is included by proponents as a "flushing" agent, intended to increase blood flow and, per the stack's originators, help distribute the other compounds — though this specific mechanism is less established in the scientific literature than the individual effects of psilocybin or Lion's Mane research on their own.
Typical Stamets Stack schedules follow a structured cycle (commonly a version of four days on, three days off) rather than daily use, partly because psilocybin's rapid tolerance makes daily dosing counterproductive regardless of the stack. As with any microdosing protocol, the psilocybin component remains illegal in most places, and neither Lion's Mane nor niacin turns an otherwise unregulated regimen into a clinically validated treatment — most of the specific "stacked" benefit claims come from Stamets' own writing and community reporting rather than controlled trials.
People considering the stack should be aware that niacin, even at supplement doses, can cause a temporary flushing reaction (skin redness, warmth, tingling) that some users find uncomfortable, and that combining multiple substances always adds complexity to dosing and any potential interactions with medications.
Related Reading
- Stamets Stack (Microdosing)
- Stacking Overview
- Neuroscience Research
- Tolerance (Glossary)
- Back to the full Glossary
This page is educational only and is not medical or legal advice. Psilocybin mushrooms are illegal in most jurisdictions; check your local laws.