The Fadiman Protocol: What It Is and How It Works

The Fadiman Protocol is a microdosing schedule built around a simple pattern: dose one day, rest for two, repeat. It's the most widely referenced approach to microdosing in the world — used in research studies, cited in clinical surveys, and followed by the majority of people who microdose psilocybin or LSD for the first time.

The protocol is named after James Fadiman, a psychologist who completed his doctorate at Stanford and spent years collecting first-person accounts from people experimenting with sub-perceptual doses of psychedelics. His 2011 book, The Psychedelic Explorer's Guide, formalized the approach and introduced it to a mainstream audience. Fadiman is often credited as the figure who turned microdosing from an informal underground practice into something structured enough to study.

The schedule runs on a three-day cycle:

Take a sub-perceptual dose of your chosen substance — typically 0.1 to 0.3 grams of dried psilocybin mushrooms, or 5 to 20 micrograms of LSD. This is roughly one-tenth to one-twentieth of a standard recreational dose. The dose should not produce hallucinations, a noticeable high, or any impairment.

Day 2 — Transition day. No dose. Some people report a residual lightness or clarity on the day after dosing — others notice nothing. Either way, this is a rest day.

No dose. This is your baseline — the day against which you're implicitly comparing how you feel on dose days.

The cycle repeats.

Most people run this schedule for four to eight weeks, then take a full break of two to four weeks before deciding whether to continue. The break matters: it lets tolerance reset fully and gives you a cleaner read on whether the protocol is actually doing anything.

The spacing is deliberate, and the logic holds up physiologically.

Psychedelics build tolerance unusually quickly. Take psilocybin two days in a row and the second dose will produce a noticeably weaker effect, because the brain's serotonin receptors — specifically the 5-HT2A receptors that psilocybin binds to — temporarily downregulate after activation. This is why recreational users typically wait at least a week between full doses.

At microdose levels, tolerance builds more slowly, but it still builds. Dosing every day would require gradually increasing amounts to maintain the same effect — which defeats the purpose and introduces unnecessary risk. The two rest days between doses appear to be enough to prevent meaningful tolerance accumulation for most people.

The rest days also serve a second function: contrast. One of the core tenets of the Fadiman Protocol is keeping a journal — noting mood, focus, energy, and sleep across all three days of each cycle. The point is to build a data set over weeks, not chase a feeling on a given morning. Without off days, that comparison becomes impossible.

The Fadiman Protocol is the baseline, but it isn't the only approach.

The most prominent alternative is the Stamets Stack, developed by mycologist Paul Stamets. Where Fadiman focuses purely on schedule, Stamets introduced a specific substance combination: a psilocybin microdose taken alongside lion's mane mushroom — a functional mushroom studied for its potential effects on nerve growth factor — and niacin. The schedule runs five days on, two days off.

The proposed mechanism behind the stack is that niacin acts as a carrier, helping distribute the other compounds more effectively. The approach has a substantial following, but the specific combination hasn't been studied in controlled clinical trials. The individual components have research behind them separately — psilocybin for mood, lion's mane for cognition — but the synergistic claim is still theoretical.

[INTERNAL LINK: What Is a Microdosing Stack? The Paul Stamets Protocol Explained]

Some people also follow an every-other-day schedule, or dose once a week. These are less studied than Fadiman and harder to draw conclusions from, but they exist and are used. The honest answer is that no protocol has been proven definitively superior — Fadiman's is simply the most documented.

[INTERNAL LINK: Microdosing LSD vs. Psilocybin: What's the Difference?]

Most of the survey-based microdosing research has used the Fadiman Protocol as its framework — it's become something of a de facto standard partly because it was the first widely published approach. The 2019 Polito and Stevenson longitudinal study at Macquarie University, which tracked 98 microdosers over six weeks, drew heavily on participants following Fadiman-style schedules.

That research found meaningful improvements in depression, stress, and concentration — but also found that creativity improvements, one of the most cited reasons people start microdosing, didn't show up in measurable data.

What Fadiman's own data collection — running for over a decade through a voluntary reporting system — consistently shows is a pattern of positive reports concentrated in mood, focus, and interpersonal ease, with a smaller but notable subset reporting anxiety or overstimulation, particularly at the higher end of the microdose range.

[INTERNAL LINK: Microdosing Benefits: What Users Report] [INTERNAL LINK: What Is Microdosing Research Actually Showing?]

A few things are worth knowing before treating this as a how-to guide.

Start lower than you think. The 0.1–0.3 gram range for psilocybin is a starting window, not a target. First-time microdosers frequently discover they're more sensitive than expected. Starting at the low end — 0.1 grams — and adjusting after observing your response is the standard recommendation.

Dose in the morning. Both psilocybin and LSD have a mild stimulant effect even at sub-perceptual levels. Dosing in the afternoon or evening can disrupt sleep, which undermines most of the benefits people are after.

Keep a journal. This is part of the original protocol design, not optional. Mood, energy, focus, sleep, social ease — tracked across all three days of each cycle. Without it, you're guessing.

Know the legal context. Psilocybin and LSD remain Schedule I substances in the US and are illegal in most countries regardless of dose size. Some cities have decriminalized psilocybin mushrooms, but that's distinct from legality.

[INTERNAL LINK: Is Microdosing Legal? What You Need to Know] [INTERNAL LINK: What Is Microdosing? A Beginner's Guide]

The Fadiman Protocol works as a starting framework because it's specific enough to follow consistently and spaced enough to generate useful personal data. Whether the benefits people attribute to it are pharmacological, placebo-driven, or some combination is still an open scientific question. What it offers, at minimum, is structure — which turns out to be most of what a first-time microdosing attempt needs.

[INTERNAL LINK: How to Microdose Psilocybin: A Step-by-Step Guide]