Microdosing Protocols: Fadiman vs. Stamets vs. EOD

Psilocybin Microdosing

0 head-to-head RCTs

No randomized controlled trial has compared the Fadiman, Stamets, or every-other-day microdosing protocols against each other. The schedule comparison is based entirely on community surveys and theoretical rationale.

Savides & Outhoff, J Psychopharmacology, 2024

38%

of microdosers use the Fadiman 1-on/2-off schedule (Anderson 2019, n=278)

3 RCTs

found no creativity benefit regardless of protocol (Prochazkova 2026)

N=191

self-blinding RCT found no effect after successful blinding (Szigeti 2021)

Savides & Outhoff, J Psychopharmacology, 2024

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Three microdosing schedules dominate the community literature: the Fadiman protocol (1 day on, 2 days off), the Stamets stack schedule (5 days on, 2 days off), and various every-other-day approaches. If you search for comparisons, you find confident recommendations. If you look for the controlled research that would justify those recommendations, you find that none of it exists.

No randomized controlled trial has compared these protocols against each other. Savides and colleagues, reviewing the full microdosing evidence base in 2024, explicitly noted the absence of schedule-specific controlled data.^[6] The protocol comparison is based on self-report surveys and theoretical rationale, not head-to-head clinical evidence. This does not make the protocols useless — but it does mean every article that declares a winner is doing so without controlled trial support.

This article covers what each protocol claims, what evidence exists for and against those claims, and what the honest state of the comparison looks like in 2026. The full overview of what microdosing is and how it works is at What Is Microdosing Psilocybin? A Complete Guide.

Legal context: Psilocybin is a Schedule I controlled substance under US federal law and is illegal for personal use in most US states. Oregon and Colorado have created regulated access frameworks. Outside the US, legal status varies widely by country. This article is educational reporting on published research.

The Comparison Table: Three Protocols, No Head-to-Head Trial Data

Before comparing the protocols, the most important caveat: no published trial has tested them against each other. The table below summarizes what each protocol involves and the evidence basis for its claims.

The "Evidence Basis" column is the critical one. For all schedules, the evidence is either community surveys without controls, or systematic reviews noting the absence of schedule-specific data.

The Fadiman Protocol: 1 Day On, 2 Days Off

The Fadiman protocol is the most widely used microdosing schedule. In a 2019 survey of 278 self-identified microdosers by Anderson and colleagues, 38% reported using a 1-on/2-off schedule consistent with the Fadiman approach — more than any other pattern.^[1]

The protocol was formally published by James Fadiman and Sofia Korb in the Journal of Psychoactive Drugs in 2019, presenting preliminary self-reported data from participants who had tried microdosing.^[2] The 1-on/2-off schedule reflects an informal tolerance hypothesis: serotonin 5-HT2A receptors may downregulate with repeated stimulation, and the two rest days are intended to allow receptor sensitivity to recover between doses. This is a plausible pharmacological rationale, but it has not been validated with pharmacokinetic data at microdosing levels.

The reported benefits in Anderson 2019 were largely consistent with what the broader microdosing community reports: improved focus (26%), mood enhancement (25%), and increased creativity (25%). Challenges included anxiety (18%) and impaired focus when the dose was too high (9%).^[1]

What Fadiman's protocol does not have: a controlled trial showing these outcomes are attributable to the pharmacological effect of psilocybin rather than expectancy. In the 2021 self-blinding citizen science RCT by Szigeti and colleagues, participants who believed they were taking active microdoses showed improvements — but when the blinding was successful (verified by whether participants could correctly guess which weeks they had received active doses), no statistically significant between-group differences were found on primary outcomes.^[4] Many participants in that study were using Fadiman-adjacent schedules.

For the full Fadiman protocol detail, see The Fadiman Protocol: The Original Microdosing Schedule.

The Stamets Stack: 5 Days On, 2 Days Off, Plus Two Additional Ingredients

The Stamets Stack adds complexity to the schedule debate. It is not just a dosing frequency — it is a combination protocol: psilocybin mushroom + lion's mane mushroom + flush niacin (niacinamide does not count), taken 5 days on and 2 days off.

The Stack originates from US Patent US20180021326A1, filed by Paul Stamets in 2019 and granted in 2022. The patent claims that the combination of a psychedelic (psilocybin), a neurotropic mushroom (lion's mane), and niacin produces enhanced neuroplasticity effects compared to any single component. The theoretical rationale: psilocybin's 5-HT2A agonism may promote BDNF and dendritic spine growth; lion's mane's hericenones stimulate NGF (nerve growth factor); niacin's vasodilatory flush effect is proposed to help distribute the compounds to peripheral nerve endings.

This theory is plausible given the individual compounds' established properties. But the combination as a protocol has no published peer-reviewed clinical trial evidence. The lion's mane NGF evidence is real (covered in detail in Lion's Mane Bioactive Compounds: Hericenones, Erinacines, and Beyond), and psilocybin's neuroplasticity effects at full doses are documented. Whether the combination at microdoses produces additive or synergistic effects has not been tested.

The largest naturalistic survey supporting microdosing generally — Rootman and colleagues, 8,703 participants, reporting lower anxiety and depression in microdosers vs non-microdosers — lists Paul Stamets as a co-author.^[3] This is a significant conflict of interest: Stamets holds the patent for one of the protocols being studied. The study's findings are not invalidated by this conflict, but they should be interpreted with it in mind. No competing analysis of the Rootman data has been published.

The 5-on/2-off schedule also raises a safety consideration. Rouaud and colleagues' 2024 analysis found that even at microdosing levels, chronic psilocybin use can activate 5-HT2B receptors — the serotonin receptor subtype associated with cardiac valvulopathy in other drug contexts (fenfluramine, cabergoline).^[7] No confirmed microdosing-related cardiac cases exist in the literature, but the theoretical risk is proportional to frequency and duration: 5 days on is more exposure than 1 day on with 2 days off, and the risk is most relevant for long-term daily or near-daily use.

For the full Stamets Stack coverage, see The Stamets Stack: Lion's Mane, Niacin, and Psilocybin.

Every Other Day and Other Schedules

Every-other-day dosing — alternating between dose days and rest days without the Fadiman 2-day gap — is practiced by a portion of the microdosing community but has no formal academic origin or well-characterized evidence base. The practical difference from Fadiman's protocol is one rest day instead of two, which means more frequent receptor stimulation.

Daily dosing is generally discouraged across the community due to tolerance concerns (consistent 5-HT2A stimulation is hypothesized to downregulate receptor sensitivity) and the elevated 5-HT2B cardiac risk concern for extended periods.

No study has directly compared every-other-day dosing to either the Fadiman or Stamets protocols in a controlled setting. Savides and colleagues confirmed in their 2024 review that schedule-specific controlled trial data does not exist for any protocol.^[6]

Why No Controlled Trial Has Compared These Schedules

The absence of head-to-head protocol data is not an oversight — it reflects a genuine methodological challenge.

Blinding is the central problem. Microdosing trials attempting placebo control have repeatedly failed to achieve adequate blinding. If participants can detect whether they received an active dose (because they notice subtle perceptual, mood, or energy effects), then the expectancy effect — believing you took an active dose — contaminates the outcome measurement. Polito and Liknaitzky's 2024 rapid review of controlled microdosing trials concluded that expectancy and placebo effects are the primary driver of most reported benefits in unblinded settings.^[5]

If much of the reported benefit is expectancy-driven, then comparing Fadiman vs. Stamets protocols in unblinded settings is comparing two sets of expectations rather than two pharmacological interventions. Whichever protocol the participant believes most strongly in will likely show the best results in unblinded data — not because it is pharmacologically superior, but because the belief is stronger.

The three-RCT creativity study by Prochazkova and colleagues, published in 2026, makes this point empirically.^[8] Creativity is among the most widely claimed benefits of microdosing — cited by 25% of microdosers in Anderson 2019 surveys. Prochazkova's team ran three separate double-blind placebo-controlled longitudinal trials and found no significant creativity benefit compared to placebo in any of them. The creativity narrative, they concluded, is driven by open-label expectancy, not specific pharmacological effects.

This finding does not mean psilocybin microdosing does nothing. Cavanna and colleagues showed that active microdoses produce measurable EEG changes distinguishable from placebo — there is biological activity at sub-perceptual doses.^[5] The Pinhas 2026 meta-analysis found modest evidence for improved cognitive flexibility, though no improvement in convergent thinking (problem-solving).^[7]

But the gap between what community surveys report and what controlled trials find is real, and it applies protocol-agnostically: whether you use Fadiman, Stamets, or every-other-day dosing, the controlled literature does not support choosing one over another on efficacy grounds.

Choosing a Schedule: What the Honest Picture Looks Like

Given the absence of head-to-head trial data, how should someone interested in microdosing think about protocol selection?

The practical considerations are:

Tolerance management: All three major protocols include rest days based on a reasonable pharmacological rationale — preventing 5-HT2A receptor downregulation. Daily dosing has no community or trial support and adds the most cardiac exposure risk.

Frequency and cardiac exposure: The Fadiman protocol's 2-day rest means lower total weekly exposure than the Stamets 5-on/2-off schedule. For someone concerned about long-term 5-HT2B cardiac risk (still theoretical, not confirmed), lower frequency is more conservative.

The Stamets Stack components: Lion's mane and niacin add complexity and cost. Lion's mane has solid NGF-stimulation evidence at higher doses (see Lion's Mane Bioactive Compounds), but whether niacin meaningfully enhances psilocybin's reach to peripheral nerves has not been tested.

Expectancy as a real factor: If expectancy contributes substantially to microdosing effects (as the controlled trial data suggests), then the protocol a person believes in most may produce the best self-reported outcomes — not because the pharmacology is superior, but because of psychological priming. This is not a criticism of the practice; expectancy effects are real effects. It does complicate any attempt to identify the pharmacologically optimal schedule.

For guidance on identifying the right dose level within whatever protocol you choose, see How to Find Your Microdose Sweet Spot. For the detailed evidence on placebo effects in microdosing research, see Is Microdosing Just Placebo? The Self-Blinding Studies. For creativity-specific evidence, see Microdosing and Creativity: What the Research Shows.

The Bottom Line

Three microdosing protocols — Fadiman (1-on/2-off), Stamets Stack (5-on/2-off with lion's mane and niacin), and every-other-day — are widely used in the psilocybin microdosing community, but no controlled trial has compared them directly. Community surveys report consistent positive outcomes across protocols, but self-blinding research (Szigeti 2021) and three creativity RCTs (Prochazkova 2026) suggest that expectancy, not specific pharmacological effects, may drive much of the reported benefit. A 2024 systematic review concluded that protocol-specific controlled evidence does not exist. The safest approach on current evidence is any schedule that includes multiple rest days and avoids daily dosing, which carries the highest theoretical cardiac risk.

Frequently Asked Questions

Which microdosing protocol is best?

No randomized controlled trial has compared microdosing protocols against each other. The Fadiman 1-on/2-off protocol is the most widely used (38% of self-reported microdosers in Anderson 2019) and has the most community documentation. The Stamets Stack (5-on/2-off with lion's mane and niacin) originates from a patent, not a clinical trial, and the combination has no published RCT evidence. A 2024 systematic review explicitly noted the absence of schedule-specific controlled data. Any claim that one protocol is proven superior to another is not supported by controlled trial evidence.

Fadiman vs Stamets microdosing — which is better?

The evidence does not support declaring one superior to the other. The Fadiman protocol has more community documentation and appears in the academic literature (Fadiman & Korb 2019). The Stamets Stack adds lion's mane and niacin based on theoretical neuroplasticity rationale, but no published trial has tested whether these additions improve outcomes compared to psilocybin alone. The Stamets schedule (5-on/2-off) involves more frequent dosing than Fadiman's (1-on/2-off), which may be a practical consideration for anyone monitoring cardiac health over extended use.

How often should you microdose psilocybin?

The most common community protocols use dosing schedules with rest days built in: 1 day on, 2 days off (Fadiman) or 5 days on, 2 days off (Stamets). Daily dosing is generally discouraged in the community due to theoretical tolerance concerns and is associated with the highest theoretical cardiac risk from chronic 5-HT2B receptor activation. No clinical trial has established an optimal dosing frequency. Psilocybin is a Schedule I controlled substance in the US, and this information is educational only.

Can you microdose psilocybin every day?

Daily psilocybin microdosing is not recommended by any major protocol and carries the highest theoretical risk of 5-HT2B receptor-related cardiac concern with long-term use (Rouaud et al., 2024). The tolerance rationale — that rest days help maintain serotonin receptor sensitivity — also argues against daily dosing. Community experience consistently discourages daily schedules. No clinical trial has tested daily microdosing safety in long-term controlled settings.

What is every other day microdosing?

Every-other-day microdosing alternates between a dose day and a rest day, providing one rest day rather than the Fadiman protocol's two. It has no formal academic origin or published RCT testing it specifically. It results in more frequent dosing than the Fadiman protocol and more rest than the Stamets schedule. Some in the community prefer it as a middle-ground approach, but there is no controlled trial data showing it to be more effective or safer than other schedules.

How do I choose a microdosing schedule?

Given the absence of controlled head-to-head trial evidence, protocol selection often comes down to personal preference, risk tolerance, and practical factors. Any schedule that includes multiple rest days is more conservative on both tolerance and cardiac grounds than daily dosing. The Fadiman protocol has the most community documentation and academic reporting. The Stamets Stack adds ingredients without RCT evidence for the combination. A 2024 systematic review noted that the entire field lacks schedule-specific controlled data, meaning no protocol can be recommended over others on evidence-based grounds alone.

Sources & References

1. 1RTHM-00541·Anderson, Thomas et al. (2019). “Psychedelic microdosing benefits and challenges: an empirical codebook..” Harm reduction journal.Study breakdown →PubMed →↩
2. 2RTHM-01054·Fadiman, James et al. (2019). “Might Microdosing Psychedelics Be Safe and Beneficial? An Initial Exploration..” Journal of psychoactive drugs.Study breakdown →PubMed →↩
3. 3RTHM-00715·Rootman, Joseph M et al. (2021). “Adults who microdose psychedelics report health related motivations and lower levels of anxiety and depression compared to non-microdosers..” Scientific reports.Study breakdown →PubMed →↩
4. 4RTHM-01441·Szigeti, Balázs et al. (2021). “Self-blinding citizen science to explore psychedelic microdosing..” eLife.Study breakdown →PubMed →↩
5. 5RTHM-00900·Polito, Vince et al. (2024). “Is microdosing a placebo? A rapid review of low-dose LSD and psilocybin research..” Journal of psychopharmacology (Oxford.Study breakdown →PubMed →↩
6. 6RTHM-00905·Savides, Isabella A et al. (2024). “Less is more? A review of psilocybin microdosing..” Journal of psychopharmacology (Oxford.Study breakdown →PubMed →↩
7. 7RTHM-00961·Pinhas, Netta et al. (2026). “Effects of psychedelic microdosing on cognitive functions: A systematic review and meta-analysis..” Neuroscience and biobehavioral reviews.Study breakdown →PubMed →↩
8. 8RTHM-00962·Prochazkova, Luisa et al. (2026). “Microdosing psilocybin and its effect on creativity: Lessons learned from three double-blind placebo controlled longitudinal trials..” Neuropharmacology.Study breakdown →PubMed →↩