Introduction
Microdosing -- the practice of taking sub-perceptual doses of psychedelics, typically one-tenth to one-twentieth of a full dose, on a regular schedule -- has evolved from a niche practice in Silicon Valley to a global phenomenon. Proponents claim improvements in creativity, focus, mood, energy, and interpersonal relationships. But as rigorous placebo-controlled research has finally caught up with the cultural enthusiasm, the picture has become considerably more nuanced. The science of microdosing is, in many ways, the science of expectation itself.
What Constitutes a Microdose?
A microdose is typically defined as a dose that produces no overt psychedelic effects -- no visual changes, no significant alterations in cognition, and no impairment in daily functioning. For LSD, this ranges from approximately 5 to 20 micrograms (a standard full dose is 100-200 micrograms). For psilocybin, it ranges from approximately 0.1 to 0.3 grams of dried mushrooms (a full dose is 2-5 grams). Common protocols include dosing every three days (the "Fadiman protocol," named after psychologist James Fadiman, who popularized the practice) or on a five-days-on, two-days-off schedule.
