TL;DR

A microdosing protocol is a schedule: a rule for how much to take, how often, and when. The named protocols — the Fadiman 1/3/1, the Stamets Stack, every-other-day, the Nightcap — all share a simple rationale. Rest days are meant to limit the rapid tolerance that the serotonin system develops to psychedelics, and the alternation between dose and non-dose days gives a self-tracker something to compare. That rationale is reasonable, and the practices are well described in surveys and in James Fadiman’s observational work. What none of it amounts to is proof: no two schedules have ever been compared in a controlled trial, the schedules are conventions rather than validated regimens, and the strongest controlled test of the underlying practice found benefits under placebo as readily as under active dose. This overview maps the landscape and sets the frame the rest of the cluster holds — popularity is not validation, and a sensible-sounding schedule is still a hypothesis.

What a protocol is, and why schedules exist at all

A protocol, in microdosing, is nothing more exotic than a schedule with a rationale attached. It specifies a target dose, a dosing rhythm — which days are “on” and which are “off” — and sometimes a time of day or a set of accompanying compounds. The reason schedules exist, rather than people simply dosing whenever they feel like it, comes down to two pressures that every practitioner account returns to.

What “protocol” means here is worth stating outright, because the word does quiet work. In this library a protocol is a documented pattern — a schedule that recurs in microdosing literature and community practice — not a clinically validated treatment and not a recommendation that anyone follow it. Describing a convention in detail is not the same as endorsing it; nothing in this cluster prescribes a dose, a schedule, or the practice itself.

The first is biological. Classic psychedelics act primarily as agonists at the serotonin 5-HT2A receptor, and that receptor system develops tolerance quickly: repeated activation produces a diminishing response, a pattern long documented for psychedelics and often described as tachyphylaxis. [1] Peer-reviewed Psychedelics Nichols DE (2016) doi:10.1124/pr.115.011478 Daily dosing would therefore be expected to blunt whatever effect a microdose produces. Rest days are the practical answer — spacing doses so the receptor system is not continuously engaged. The pharmacology behind this is set out in the 5-HT2A mechanism article, and the cluster treats the rest-day logic in detail in tolerance and cycling.

The second pressure is methodological. A person microdosing has no control group and no blind; their only comparison is between their own dose days and their own rest days. A schedule that interleaves the two creates that contrast — a crude within-person comparison that is the entire basis of self-evaluation. This is also, as the cluster keeps flagging, the contrast most vulnerable to expectation: you generally know which days are dose days, and you expect them to feel different. [2] Clinical trial Self-blinding citizen science to explore psychedelic microdosing Szigeti B, Kartner L, Blemings A, Rosas F, Feilding A, Nutt DJ, Carhart-Harris RL, Erritzoe D (2021) doi:10.7554/eLife.62878

The landscape of named protocols

A handful of schedules recur across practitioner writing and survey data. They differ in their rhythm and their additions, not in any demonstrated outcome.

The Fadiman protocol, often written as 1/3/1, is the reference point: dose on day one, rest on days two and three, dose again on day four, and so on. It is named for James Fadiman, whose observational work — correspondence with and daily self-reports from over a thousand people across dozens of countries — is the largest descriptive dataset behind any schedule. [3] Observational Might Microdosing Psychedelics Be Safe and Beneficial? An Initial Exploration Fadiman J, Korb S (2019) doi:10.1080/02791072.2019.1593561 That volume is exactly why it functions as the practitioner baseline, and exactly why it is easy to overread: a large body of uncontrolled self-reports is a large body of uncontrolled self-reports. The schedule has its own detailed article.

The Stamets Stack keeps a four-days-on, three-days-off rhythm but adds two compounds to the psilocybin: Lion’s Mane mushroom (Hericium erinaceus) and niacin (vitamin B3). The rationale is mechanistic — Lion’s Mane has a preclinical association with nerve growth factor, and niacin is offered a “distribution” story that has no good support — and the combination has never been tested in a controlled trial. Surveys confirm stacking is common in the wild. [4] Observational Adults who microdose psychedelics report health related motivations and lower levels of anxiety and depression compared to non-microdosers Rootman JM, Kryskow P, Harvey K, Stamets P, Santos-Brault E, Kuypers KPC, Polito V, Bourzat F, Walsh Z (2021) doi:10.1038/s41598-021-01811-4 The one observational study that compared stacked and unstacked microdosers found no overall difference in mood and mental-health outcomes. [5] Observational Psilocybin microdosers demonstrate greater observed improvements in mood and mental health at one month relative to non-microdosing controls Rootman JM, Kiraga M, Kryskow P, Harvey K, Stamets P, Santos-Brault E, Kuypers KPC, Walsh Z (2022) doi:10.1038/s41598-022-14512-3 The stack gets its own article.

Beyond these, every-other-day schedules (a simple Monday/Wednesday/Friday calendar) and the evening Nightcap are lower-documentation variations, covered alongside the trade-offs between calendars in dosing schedules compared. All of these sit on top of two more fundamental questions — what dose to take, addressed in finding your dose, and how to evaluate whether anything is happening, addressed in tracking and evaluation.

The evidence tiers — and why they don’t rank the schedules

It is tempting to read the differing amounts of evidence behind each schedule as a ranking, with Fadiman at the top. That is a misreading, and an important one to avoid. The tiers describe how much observational attention a practice has received, not how effective it is.

Fadiman’s protocol sits at the “documented” tier because it has the largest descriptive dataset, not because a study showed it beats the alternatives. [3] Observational Might Microdosing Psychedelics Be Safe and Beneficial? An Initial Exploration Fadiman J, Korb S (2019) doi:10.1080/02791072.2019.1593561 The Stamets Stack sits at a “plausible plus anecdote” tier because it has a mechanistic story and high anecdotal volume but no trial. [5] Observational Psilocybin microdosers demonstrate greater observed improvements in mood and mental health at one month relative to non-microdosing controls Rootman JM, Kiraga M, Kryskow P, Harvey K, Stamets P, Santos-Brault E, Kuypers KPC, Walsh Z (2022) doi:10.1038/s41598-022-14512-3 Timing variations like the Nightcap sit at an “early” tier because sub-perceptual timing has barely been studied. Personalized variations are frankly anecdotal. None of this is a league table of effectiveness, because the comparison that would produce one — schedules tested against each other, and against placebo — has not been done. [6] Peer-reviewed Microdosing psychedelics: More questions than answers? An overview and suggestions for future research Kuypers KPC, Ng L, Erritzoe D, Knudsen GM, Nichols CD, Nichols DE, Pani L, Soula A, Nutt D (2019) doi:10.1177/0269881119857204 [7] Systematic review The emerging science of microdosing: A systematic review of research on low dose psychedelics (1955-2021) and recommendations for the field Polito V, Liknaitzky P (2022) doi:10.1016/j.neubiorev.2022.104706

It helps to keep the kinds of evidence separate, because the protocols draw on all of them and each answers a different question:

What each kind of evidence can and cannot show
Evidence typeWhat it can showWhat it cannot show
Community reports & surveysHow protocols are used, and how common they areThat a protocol caused any reported benefit
Observational studiesPatterns and associations between microdosing and outcomesCause — microdosers differ from non-microdosers in ways no survey controls for
Mechanistic reasoningWhy a spacing or added compound might matter, biologicallyThat the mechanism produces a benefit in people who microdose
Controlled trialsWhether a specific effect exceeds placeboThe schedules have not been put through this head-to-head
The named protocols at a glance
ProtocolRhythmDistinctive featureEvidence posture
Fadiman 1/3/11 dose day, 2 rest days, repeatThe documented baselineLargest observational dataset; no controlled comparison
Stamets Stack4 days on, 3 days offAdds Lion’s Mane + niacinMechanistic rationale; no trial; stacking showed no added benefit observationally
Every-other-dayM/W/F or alternatingSimpler calendarLess contrast data; higher tolerance-creep risk
NightcapEvening doseTime-of-day variationSparse sub-perceptual timing evidence

The frame this cluster holds

Everything that follows is organized around four distinctions, because protocols are precisely the topic where they are easiest to lose.

Popularity is not validation. That the Fadiman schedule is the most documented says practitioners adopted it widely and reported on it diligently; it does not say it works, or that it works better than any other schedule. [3] Observational Might Microdosing Psychedelics Be Safe and Beneficial? An Initial Exploration Fadiman J, Korb S (2019) doi:10.1080/02791072.2019.1593561 Observational volume and effectiveness are different axes.

A convention is not a clinical regimen. Rest days, contrast days, four-week cycles — these are sensible-sounding habits that emerged from self-experimentation, not regimens established by trials. Throughout the cluster the rationale for a convention is presented as rationale, clearly labelled.

Mechanistic plausibility is not demonstrated benefit. The tolerance logic for rest days is biologically reasonable, and the Lion’s Mane rationale has a preclinical basis. Reasonable and preclinical are not the same as shown in people who microdose. [1] Peer-reviewed Psychedelics Nichols DE (2016) doi:10.1124/pr.115.011478

Reports are not outcomes. Self-tracking on a schedule one chose and expects to work produces exactly the data most exposed to expectation. The self-blinding evidence and the systematic reviews are the reason this matters: when the practice is tested directly, the effect tracks expectation as much as the active dose. [2] Clinical trial Self-blinding citizen science to explore psychedelic microdosing Szigeti B, Kartner L, Blemings A, Rosas F, Feilding A, Nutt DJ, Carhart-Harris RL, Erritzoe D (2021) doi:10.7554/eLife.62878 [8] Systematic review Is microdosing a placebo? A rapid review of low-dose LSD and psilocybin research Polito V, Liknaitzky P (2024) doi:10.1177/02698811241254831 The reasoning is laid out in how to read microdosing claims.

Key concepts
Protocol = schedule + rationale
A microdosing protocol specifies a dose, a rhythm of dose and rest days, and sometimes timing or added compounds; the named protocols differ in rhythm and additions, not in any demonstrated outcome. [3] Observational Might Microdosing Psychedelics Be Safe and Beneficial? An Initial Exploration Fadiman J, Korb S (2019) doi:10.1080/02791072.2019.1593561
Rest days limit tolerance
Psychedelics produce rapid tolerance at the 5-HT2A receptor, so schedules space doses to avoid continuous receptor engagement. [1] Peer-reviewed Psychedelics Nichols DE (2016) doi:10.1124/pr.115.011478
Contrast days enable self-comparison
Alternating dose and rest days is the only within-person comparison a self-tracker has — and the comparison most exposed to expectation. [2] Clinical trial Self-blinding citizen science to explore psychedelic microdosing Szigeti B, Kartner L, Blemings A, Rosas F, Feilding A, Nutt DJ, Carhart-Harris RL, Erritzoe D (2021) doi:10.7554/eLife.62878
Documentation is not effectiveness
Fadiman’s schedule is the most documented because it has the largest observational dataset, not because it was shown to outperform alternatives. [3] Observational Might Microdosing Psychedelics Be Safe and Beneficial? An Initial Exploration Fadiman J, Korb S (2019) doi:10.1080/02791072.2019.1593561
Conventions, not regimens
The named protocols are practitioner conventions with an observational evidence base, never compared head-to-head or against placebo in controlled trials. [6] Peer-reviewed Microdosing psychedelics: More questions than answers? An overview and suggestions for future research Kuypers KPC, Ng L, Erritzoe D, Knudsen GM, Nichols CD, Nichols DE, Pani L, Soula A, Nutt D (2019) doi:10.1177/0269881119857204 [7] Systematic review The emerging science of microdosing: A systematic review of research on low dose psychedelics (1955-2021) and recommendations for the field Polito V, Liknaitzky P (2022) doi:10.1016/j.neubiorev.2022.104706

Frequently asked questions

Are microdosing protocols scientifically proven?

No. The named protocols are schedules that recur in research literature, surveys, and community reports; they give structure for studying and self-tracking the practice, but no controlled trial has shown any schedule to be clinically effective or superior to another. [6] Peer-reviewed Microdosing psychedelics: More questions than answers? An overview and suggestions for future research Kuypers KPC, Ng L, Erritzoe D, Knudsen GM, Nichols CD, Nichols DE, Pani L, Soula A, Nutt D (2019) doi:10.1177/0269881119857204 Current evidence has not established that microdosing produces effects beyond expectation in the first place. [8] Systematic review Is microdosing a placebo? A rapid review of low-dose LSD and psilocybin research Polito V, Liknaitzky P (2024) doi:10.1177/02698811241254831 A protocol is best understood as a documented convention, not a validated treatment regimen.

Is there a 'best' microdosing protocol?

No protocol has been shown to outperform another, because microdosing schedules have never been compared head-to-head in a controlled trial. [6] Peer-reviewed Microdosing psychedelics: More questions than answers? An overview and suggestions for future research Kuypers KPC, Ng L, Erritzoe D, Knudsen GM, Nichols CD, Nichols DE, Pani L, Soula A, Nutt D (2019) doi:10.1177/0269881119857204 The Fadiman 1/3/1 schedule is the most documented and the one most practitioner accounts treat as a baseline, but “most documented” describes how much observational data exists, not that the schedule produces better results. [3] Observational Might Microdosing Psychedelics Be Safe and Beneficial? An Initial Exploration Fadiman J, Korb S (2019) doi:10.1080/02791072.2019.1593561 The honest position is that the named protocols are reasonable conventions built on a shared rationale — limit tolerance, create comparison data — and that the choice between them is not settled by evidence.

Why do protocols include rest days instead of dosing every day?

Two reasons, one biological and one methodological. Biologically, the serotonin 5-HT2A receptor that psilocin acts on shows rapid tolerance with repeated activation, so daily dosing is expected to blunt any effect; rest days are intended to let the receptor system reset. [1] Peer-reviewed Psychedelics Nichols DE (2016) doi:10.1124/pr.115.011478 Methodologically, rest days create a contrast between dose days and non-dose days, which is the only within-person comparison a self-tracker has. Both are sensible rationales rather than findings from controlled studies of the schedules themselves.

Are these protocols medical regimens?

No. They are conventions that emerged from self-experimentation and observational reports, not regimens validated by clinical trials and not prescribed by clinicians. [3] Observational Might Microdosing Psychedelics Be Safe and Beneficial? An Initial Exploration Fadiman J, Korb S (2019) doi:10.1080/02791072.2019.1593561 This page describes what practitioners do and what the evidence does and does not support; it does not recommend a schedule, a dose, or that anyone microdose. Psilocybin is a controlled substance in most jurisdictions, and decisions about any substance belong with a qualified professional.

Does following a documented protocol make microdosing more likely to work?

Following a structured schedule makes your experience easier to track and compare, but it does not make the underlying effect more real. The strongest controlled test of microdosing to date found that benefits appeared under placebo as well as active dose, [2] Clinical trial Self-blinding citizen science to explore psychedelic microdosing Szigeti B, Kartner L, Blemings A, Rosas F, Feilding A, Nutt DJ, Carhart-Harris RL, Erritzoe D (2021) doi:10.7554/eLife.62878 and systematic reviews conclude that evidence of effects beyond expectation remains limited. [8] Systematic review Is microdosing a placebo? A rapid review of low-dose LSD and psilocybin research Polito V, Liknaitzky P (2024) doi:10.1177/02698811241254831 A well-designed protocol improves the quality of your self-observation; it does not convert an expectation-driven effect into a pharmacological one.

What is 'stacking', and is it part of a protocol?

Stacking means combining psilocybin with other compounds — most commonly Lion’s Mane mushroom and niacin, the combination popularized as the Stamets Stack. Surveys find stacking is a common real-world practice. [4] Observational Adults who microdose psychedelics report health related motivations and lower levels of anxiety and depression compared to non-microdosers Rootman JM, Kryskow P, Harvey K, Stamets P, Santos-Brault E, Kuypers KPC, Polito V, Bourzat F, Walsh Z (2021) doi:10.1038/s41598-021-01811-4 It is a protocol variation rather than a separate schedule, and the rationale for the added compounds is mechanistic and largely preclinical; the one observational study that compared stacked and unstacked microdosers found no overall difference in mood and mental-health outcomes. [5] Observational Psilocybin microdosers demonstrate greater observed improvements in mood and mental health at one month relative to non-microdosing controls Rootman JM, Kiraga M, Kryskow P, Harvey K, Stamets P, Santos-Brault E, Kuypers KPC, Walsh Z (2022) doi:10.1038/s41598-022-14512-3