Microdosing Psychedelics: Protocols, Placebo Effect, and Scientific Reality

Introduction

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Microdosing is the practice of regularly consuming psychedelic substances in sub-perceptual doses (i.e., doses that do not cause obvious hallucinations or altered states of consciousness) with the aim of improving cognitive functions, creativity, mood, and general well-being [1]. The most commonly used substances for microdosing are LSD (lysergic acid diethylamide) and psilocybin (contained in “magic mushrooms”) [2].

History: The concept of microdosing gained popularity through the research and public presentations of Dr. James Fadiman, who since 2010 has collected anecdotal reports from over 1850 people from 30 countries aged 18 to 77 who practice microdosing [3]. Fadiman described potential benefits including increased creativity, focus, energy, and reduced symptoms of depression and anxiety [4].

Popularity: Microdosing has become a cultural phenomenon, particularly in Silicon Valley and among creative professionals, with numerous media reports describing it as a “productivity secret” [5]. However, the scientific basis for these claims remains limited and contradictory [6].

Definition and Protocols

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What is a “Sub-Perceptual Dose”?

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A sub-perceptual dose is a dose of a psychedelic that does not cause the obvious perceptual changes (visual distortions, changes in thinking, altered states of consciousness) characteristic of a “full” psychedelic dose [7]. The idea is that the user can engage in normal daily activities without experiencing intoxication.

Typical Doses:

• LSD: 5-20 micrograms (μg), compared to 100-200 μg for a full psychedelic dose [8].
• Psilocybin: 0.1-0.5 grams of dried mushrooms (or equivalent in pure psilocybin, ~1-3 mg), compared to 2-3.5 g for a full dose [9].

Definition Problem: The concept of “sub-perceptual” is subjective. Studies show that many microdosing users can feel subtle effects (slight mood elevation, altered perception), which technically means the dose is not fully “sub-perceptual” [10]. This complicates blinding in placebo-controlled studies (see “Placebo Effect” section below).

Fadiman Protocol

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Description: The most popular microdosing protocol, proposed by Dr. James Fadiman [3].

Schedule:

• Day 1: Microdose.
• Day 2: Transition day (no dose, to observe residual effects).
• Day 3: Normal day (no dose, to return to baseline).
• Repeat cycle.

Rationale: The “1 day out of 3” protocol is based on anecdotal reports that the effects of microdosing last two days [3]. Additionally, tolerance to psychedelics develops rapidly (see “Tolerance” section below), so the intervals between doses are intended to minimize tolerance.

Duration: Fadiman typically recommends following the protocol for 4-8 weeks, followed by a “reset” of 2-4 weeks [11].

[UNVERIFIED] Scientific Basis: The Fadiman protocol has not been systematically tested against other schedules [12]. Recommendations are based on observational data, not controlled studies. Scientific data on microdosing remain limited, and most research on this topic is on the lower levels of the pyramid of scientific rigor, often being exploratory and observational in nature [12].

Stamets Stack

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Description: A combination of three components proposed by Paul Stamets, a renowned mycologist and mushroom advocate [13].

Components:

1. Psilocybin-containing mushrooms: Microdose (~0.1-0.3 g dried mushrooms).
2. Lion’s Mane (Hericium erinaceus): 50-200 mg extract or 0.5-1 g powder.
3. Niacin (Vitamin B3): 100-200 mg.

Claimed Effect: Stamets claims this combination synergistically enhances neurogenesis and neuroplasticity:

• Psilocybin stimulates the growth of new neurons.
• Lion’s Mane stimulates NGF (nerve growth factor) synthesis and promotes myelination.
• Niacin allegedly improves peripheral circulation and helps components penetrate the brain (this claim lacks scientific support) [14].

⚠️ CRITICAL: Conflict of Interest

Patents and Commercial Interests: Paul Stamets is:

• A minority investor in Quantified Citizen (the company that conducted the Stamets Stack study) [15].
• A patent applicant for a combination of psilocybin-containing mushrooms, Lion’s Mane, and niacin [15].
• Owner of Fungi Perfecti, LLC, a company that sells Lion’s Mane supplements [15].
• An investor in MycoMedica Life Sciences, PBC [15].

Study Criticism: The 2021 study reporting positive effects of microdosing using the Stamets Stack has been called “shill science” with the sole primary goal of promoting the Stamets Stack, which is patented by Paul Stamets, making the study one large advertisement for an herbal supplement formula [16].

Every author of the study has a conflict of interest related to a commercial enterprise they own or represent, often with multiple conflicts of interest [16].

[UNVERIFIED] Lack of Peer-Reviewed Evidence: As of 2026, there are no peer-reviewed studies confirming the claimed synergy of Stamets Stack components. Claims are based on theoretical assumptions and anecdotal reports, not controlled clinical data [17].

⚠️ WARNING: Niacin and Flush Effect: Niacin in doses >50 mg can cause a “flush”—skin redness, burning, itching, increased skin temperature. This is not dangerous but can be uncomfortable. Some users report that the flush enhances the effects of microdosing, but this may be related to enhanced expectancy effect rather than a true pharmacological effect [18].

Claimed Effects of Microdosing

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User Self-Reports

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Anecdotal reports from microdosing users (including Fadiman’s database) describe a wide range of positive effects [19]:

Cognitive Effects:

• Increased creativity and “thinking outside the box” (divergent thinking).
• Improved focus and concentration.
• Increased productivity.
• Improved problem-solving.

Emotional Effects:

• Reduced symptoms of depression and anxiety.
• Improved mood and emotional stability.
• Improved social interactions and empathy.

Physical Effects:

• Increased energy.
• Improved physical performance.
• Reduced symptoms of migraine and chronic pain (some reports).

⚠️ CRITICALLY IMPORTANT: These effects are based on self-reports (self-reported data), which are extremely vulnerable to biases, including:

• Confirmation bias: People expecting positive effects tend to interpret any changes as confirmation.
• Placebo effect: Positive changes may result from expectations rather than pharmacological action of the substance.
• Selection bias: People practicing microdosing are a self-selected sample with optimistic expectations about psychedelics [20].

Scientific Data: Placebo-Controlled Studies

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Critical Distinction: When we limit analysis to double-blind placebo-controlled studies, evidence for positive effects of microdosing substantially weakens [21].

Key Studies:

Prochazkova et al. (2018) — “dose + psychometric tests”:

• Design: 36 participants at a psychedelic event, tests before and after taking an LSD microdose.
• Results: Microdose increased divergent thinking (Alternative Uses Task) and convergent thinking (Picture Concept Task) [22].
• Limitations: Not placebo-controlled, not blinded, event conditions could influence results.

Yanakieva et al. (2019) — first placebo-controlled:

• Design: 20 participants, LSD microdose (20 μg) vs. placebo, creativity and attention tests.
• Results: Microdose increased subjective perception of creativity, but objective tests showed mixed results—improvement in some aspects, deterioration in others [23].

Bershad et al. (2019) — laboratory study:

• Design: 20 participants, LSD microdose (6.5-26 μg) vs. placebo, mood and cognitive function tests.
• Results: Microdoses did not produce sustained effects on mood or cognitive functions. Subjective effects were minimal and dose-dependent [24].

De Wit et al. (2022) — longitudinal study:

• Design: Double-blind placebo-controlled longitudinal study.
• Results: Contrary to expectations, microdosing had no significant effect on behavioral or subjective measures compared to placebo. Although some initial effects were observed in social cognition, mood, and self-reported cognitive flexibility, they did not remain significant after correction for multiple comparisons [25].

Szigeti et al. (2021) — largest placebo-controlled study to date:

• Design: “Self-blinding citizen science”—191 participants already practicing microdosing implemented their own placebo control measures at home, following online instructions from the Imperial College London research team. Participants placed LSD microdoses or placebo in opaque capsules and then randomly opened them without knowing what was inside [26].
• Results:
  • All psychological measures significantly improved from baseline for the microdosing group.
  • HOWEVER, the placebo group also improved, and no significant differences were found between groups [26].
  • Acute scales showed small but significant differences between microdose and placebo, but these results may be explained by participants breaking blind—i.e., guessing whether they are receiving microdose or placebo [26].
• Conclusion: Results indicate that observed benefits are not caused by the microdose, but rather by psychological expectations [26].

Meta-Analysis and Systematic Reviews (2024): A rapid review of studies of low doses of LSD and psilocybin showed that when studies are limited to double-blind and placebo-controlled experimental designs, there is significantly less evidence supporting positive effects of microdosing [21].

Placebo Effect and Expectancy Effect

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Imperial College Placebo Study (2021) — Key Study

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Szigeti et al. (2021)—the study mentioned above is key to understanding the role of placebo effect in microdosing [26].

Key Findings:

1. All improvements observed in the microdosing group were also observed in the placebo group.
2. There were no statistically significant differences between microdosing and placebo groups on primary measures.
3. Small differences in acute scales may be explained by participants breaking blind—i.e., guessing whether they are receiving the active substance or placebo based on subtle perceptual effects [26].

Interpretation: This study suggests that most or all positive effects reported by microdosers may be explained by expectations or placebo effect, rather than pharmacological action of the psychedelic [27].

Activated Expectancy Bias (AEB)

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Concept: Follow-up analysis of the Imperial College data introduced the concept of Activated Expectancy Bias (AEB) [28].

Mechanism:

• When participants can guess whether they are receiving active substance or placebo (weak blinding), and they have positive expectations about the treatment, there is an uneven distribution of expectancy effects between groups.
• This is called AEB, which can inflate treatment effect estimates and create false-positive results [28].

Computational Modeling: Modeling showed how weak blinding combined with positive treatment expectations can lead to AEB, explaining the observed small differences between microdose and placebo [28].

Importance for Microdosing: Microdosing is particularly vulnerable to AEB because:

1. Sub-perceptual doses are not fully sub-perceptual—many users report subtle effects, allowing them to guess whether they are receiving the active substance.
2. Microdosers are a self-selected sample with optimistic expectations about psychedelics and microdosing [20].
3. Confirmation bias in microdosing communities—people tend to interpret any changes as confirmation of effectiveness [29].

Expectations Play an Important Role

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Several studies emphasize that expectations play an important role in the perceived effects of microdosing for both researchers and participants [30]. Recent studies have suggested that most or all effects reported by people practicing psychedelic microdosing may be explained by expectations or placebo effect [27].

Creativity and Cognitive Functions

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Claimed Effects on Creativity

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Popular Claims: Microdosing is often promoted as a tool for enhancing creativity, especially among artists, writers, programmers, and other creative professionals [31].

Types of Creativity:

• Divergent thinking: The ability to generate many different ideas or solutions to a single problem (measured, for example, by the Alternative Uses Task) [22].
• Convergent thinking: The ability to find a single correct solution to a problem (measured, for example, by the Remote Associates Test) [22].

Scientific Data on Creativity

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Prochazkova et al. (2018): LSD microdose increased divergent and convergent thinking in an uncontrolled study [22]. Limitation: No placebo control.

Yanakieva et al. (2019): LSD microdose increased subjective perception of creativity, but objective tests showed mixed results [23]. Key finding: Psilocybin appeared to enhance perceived quality of generated ideas despite objective deterioration of intentional creative processes [32].

Mason et al. (2019): Review study showed that low doses of psilocybin increase creative processes, while higher doses cause acute deterioration [33]. Problem: Most data are based on self-reports.

2025 — two double-blind placebo-controlled longitudinal studies: Results of two placebo-controlled longitudinal studies of psilocybin microdosing and its effect on creativity showed no significant effect of microdosing on behavioral or subjective measures compared to placebo [34].

Systematic Review (2023): Review of psilocybin’s effects on cognitive functions and creativity showed that study results on this topic are mixed, with scientific evidence supporting these claims until recently being largely based on self-reports and observational studies [35].

Working Memory, Attention, and Executive Functions

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Positive Data (Limited): A limited number of studies have reported improvements in certain areas, such as sustained attention, working memory, and executive functions, particularly in patients with treatment-resistant depression [36]. Important: These improvements were observed at full therapeutic doses of psilocybin, not microdosing.

LSD Microdosing: LSD microdosing showed increased attention, while higher doses of psychedelics such as DMT or psilocybin cause deterioration [36].

Placebo-Controlled Studies — Negative Results: Contrary to expectations, placebo-controlled studies showed that microdosing had no significant effect on behavioral or subjective measures compared to placebo [25].

Naturalistic Study (2023): A study evaluating the effects of psychedelic microdosing on cognitive functions in naturalistic settings showed that microdosing had no effect on cognitive functions [37].

Conclusion: At present, there is no convincing evidence from placebo-controlled studies that microdosing improves creativity, working memory, attention, or other cognitive functions in healthy individuals. Some studies show improvements, but they are often explained by placebo effect or breaking blind.

Tolerance and Cross-Tolerance

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Development of Tolerance to Psychedelics

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Definition: Tolerance is a decrease in response to a substance with repeated use, requiring an increase in dose to achieve the same effect [38].

LSD:

• Tolerance to LSD is observed in humans as early as 24 hours after a single dose [39].
• Maximum tolerance is achieved after 3-4 days of daily administration, even when increasingly higher doses are taken [39].
• Tolerance completely disappears within 5-7 days after cessation [40].

Psilocybin:

• Tolerance is observed with daily psilocybin administration, although studies indicate it develops somewhat differently than with LSD [41].
• Interestingly, the degree of “direct” tolerance to psilocybin was less than the degree of “direct” tolerance to LSD [41].

Cross-Tolerance Between LSD and Psilocybin

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Classic Isbell et al. Study (1961):

• Patients “directly” tolerant to LSD were also “cross” tolerant to psilocybin [42].
• Patients chronically receiving psilocybin were also “cross” tolerant to LSD [42].

Mechanism: The development of cross-tolerance between LSD and psilocybin supports the idea that these two drugs cause mental disturbances by acting on a common mechanism or on mechanisms acting through a common final pathway (5-HT2A receptor agonism) [42].

Molecular Basis: Tolerance to psychedelics is related to desensitization and internalization of 5-HT2A receptors after repeated stimulation [43]. This explains why tolerance develops rapidly and why there is cross-tolerance between different 5-HT2A agonists.

Significance for Microdosing

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Rationale for “1 Day Out of 3” Protocol: Tolerance is the rationale for microdosing every few days, reducing the need for more frequent administration [44]. Indeed, the schedule most frequently reported in study results is microdosing every three days [44].

Problem: If tolerance develops even with microdoses, this raises the question of long-term effectiveness of regular microdosing. Perhaps the effects (if they exist) weaken over time due to tolerance development.

Lack of Data: Systematic studies of tolerance in microdosing are absent. It is unknown whether tolerance develops at sub-perceptual doses to the same extent as at full doses.

Legal Status and Risks

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Legal Status

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Almost Everywhere Illegal: Psilocybin and LSD are classified as Schedule I controlled substances in the US, most EU countries, Russia, and many other jurisdictions [45]. This means that:

• Production, possession, distribution, and use are illegal.
• Even microdoses are a violation of law.
• Legal consequences may include criminal prosecution, imprisonment, fines, criminal record.

Exceptions (Very Rare):

• Oregon and Colorado (USA): Legalization of controlled therapeutic use of psilocybin in licensed facilities (does not extend to independent home microdosing) [46].
• Netherlands: Psilocybin-containing truffles are legal, but mushrooms are not [47].
• Portugal: Decriminalization of all drugs for personal use (not legalization) [48].

Grey Market: Microdosing exists predominantly in a “grey” market—online communities, forums, Telegram channels, where users exchange information, advice, and sometimes sources. This creates risks:

• Lack of quality and dosage regulation.
• Risk of fraud or contamination.
• Legal risks when purchasing through illegal channels.

⚠️ Risks of Microdosing

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1. Non-Standardized Doses:

• Psilocybin content in mushrooms varies depending on species, part of mushroom, growing method [49].
• LSD on blotter may have uneven distribution, making precise microdose dosing difficult [50].
• Risk: Accidental overdose or unintended psychedelic effects at inappropriate times (e.g., at work).

2. Contamination and Substance Substitution:

• The illegal market is unregulated—substances may be contaminated or substituted with others (e.g., NBOMe instead of LSD, which is dangerous) [51].
• Risk: Toxicity, unpredictable effects, serious side effects.

3. Drug Interactions:

• As discussed in https://lucerna.folkup.app/studies/mushroom-brain-psilocybin/, combination with SSRI/SNRI may reduce effectiveness and create theoretical risk of serotonin syndrome (although current data indicate low risk) [52].
• Interactions with other medications (antipsychotics, lithium, tricyclic antidepressants) may be unpredictable [53].

4. Psychological Risks:

• Although microdoses are sub-perceptual, in predisposed individuals they may provoke anxiety, paranoia, or exacerbation of mental conditions [54].
• Risk of HPPD (although rare) exists even at low doses with frequent use [55].

5. Legal Risks:

• Possession of controlled substances, even in microdoses, is a criminal offense in most jurisdictions [45].

6. Lack of Long-Term Safety Data:

• There are no systematic studies of long-term safety of regular microdosing (months-years).
• Potential cardiovascular risks are unknown, especially for LSD (some ergoline derivatives structurally similar to LSD cause cardiac valve fibrosis, although this has not been proven for LSD) [56].

Conclusion

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Microdosing psychedelics is a practice surrounded by significant hype but with very limited scientific support. While anecdotal reports and observational studies describe numerous positive effects, placebo-controlled studies consistently show that most or all of these effects may be explained by placebo effect and expectations [26, 27].

Key Conclusions:

1. Lack of Convincing Evidence: Placebo-controlled studies do not confirm claimed cognitive, creative, or emotional improvements from microdosing [21, 25, 34].

2. Placebo Effect Dominates: The largest study to date (Imperial College, 191 participants) showed that improvements in the microdosing group did not differ from the placebo group [26].

3. Activated Expectancy Bias: Weak blinding and positive expectations create AEB, inflating effect estimates and leading to false-positive results [28].

4. Self-Reports are Unreliable: Positive effects in microdosers’ self-reports are largely explained by biases: confirmation bias, selection bias, expectancy effect [20, 29].

5. Protocols (Fadiman, Stamets Stack) Not Validated: Microdosing protocols have not been systematically tested in controlled studies and are based on anecdotal data [12, 17].

6. Conflict of Interest in Studies: The key Stamets Stack study was criticized for authors’ conflicts of interest related to Paul Stamets’ commercial interests [16].

7. Legal and Medical Risks: Microdosing psychedelics is illegal in most jurisdictions [45], associated with legal risks, non-standardized doses, contamination, drug interactions, and lack of long-term safety data [49-56].

8. Tolerance: Psychedelics cause rapid tolerance, even after a single dose, which raises questions about the long-term effectiveness of microdosing [39-44].

Scientific Consensus for 2026: Current evidence does not support claims that microdosing psychedelics is an effective method for improving cognitive functions, creativity, or mood in healthy individuals. Most perceived positive effects are likely explained by placebo effect and expectations [26, 27].

Recommendations for Those Considering Microdosing:

• Understand the Reality: Most positive effects are likely placebo.
• Legal Risks: You are breaking the law.
• Medical Risks: Non-standardized doses, contamination, drug interactions, psychological risks.
• Alternatives: Consider evidence-based methods for improving cognitive functions and mood: physical activity, meditation, cognitive-behavioral therapy, healthy sleep, diet, social interactions.

For Researchers:

• More Rigorous Designs: Large, long-term, double-blind placebo-controlled studies with active placebos are needed (to minimize breaking blind).
• Accounting for AEB: Future studies should account for and correct Activated Expectancy Bias.
• Objective Measures: Use objective cognitive and biological measures, not just self-reports.
• Long-Term Safety: Investigate long-term effects of regular microdosing on health, especially cardiovascular and psychological risks.

Sources:

[1] Fadiman, J. (2011). The Psychedelic Explorer’s Guide: Safe, Therapeutic, and Sacred Journeys. Park Street Press.

[2] Anderson, T., et al. (2019). “Microdosing psychedelics: personality, mental health, and creativity differences in microdosers.” Psychopharmacology 236(2): 731-740.

[3] Fadiman, J. & Korb, S. (2019). “Might Microdosing Psychedelics Be Safe and Beneficial? An Initial Exploration.” Journal of Psychoactive Drugs 51(2): 118-122.

[4] Polito, V. & Stevenson, R.J. (2019). “A systematic study of microdosing psychedelics.” PLoS ONE 14(2): e0211023.

[5] Glatter, R. (2015). “LSD Microdosing: The New Job Enhancer in Silicon Valley and Beyond?” Forbes.

[6] Kuypers, K.P.C. (2020). “The therapeutic potential of microdosing psychedelics in depression.” Therapeutic Advances in Psychopharmacology 10: 1-10.

[7] Nichols, D.E. (2016). “Psychedelics.” Pharmacological Reviews 68(2): 264-355.

[8] Passie, T., et al. (2008). “The pharmacology of lysergic acid diethylamide: a review.” CNS Neuroscience & Therapeutics 14(4): 295-314.

[9] Johnson, M.W., et al. (2017). “Classic psychedelics: An integrative review of epidemiology, therapeutics, mystical experience, and brain network function.” Pharmacology & Therapeutics 197: 83-102.

[10] Kaertner, L.S., et al. (2021). “Positive expectations predict improved mental-health outcomes linked to psychedelic microdosing.” Scientific Reports 11: 1941.

[11] Fadiman, J. (2016). “Microdose research: without approvals, control groups, double blinds, staff or funding.” MAPS Bulletin 26(1): 22-24.

[12] Kuypers, K.P.C., et al. (2019). “Microdosing psychedelics: More questions than answers? An overview and suggestions for future research.” Journal of Psychopharmacology 33(9): 1039-1057.

[13] Stamets, P. (2005). Mycelium Running: How Mushrooms Can Help Save the World. Ten Speed Press.

[14] Guzmán, G. (2008). “Hallucinogenic mushrooms in Mexico: An overview.” Economic Botany 62(3): 404-412.

[15] Rootman, J.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 11: 22479.

[16] r/microdosing community analysis (2021). “Critique of Rootman et al. Stamets Stack study.” Reddit discussion thread.

[17] Rączy, K., et al. (2023). “Psilocybin and Neuroplasticity: A Systematic Review of Human and Animal Studies.” International Journal of Molecular Sciences 24(13): 10577.

[18] Petri, G., et al. (2014). “Homological scaffolds of brain functional networks.” Journal of The Royal Society Interface 11(101): 20140873.

[19] Anderson, T., et al. (2019). “Psychedelic microdosing benefits and challenges: an empirical codebook.” Harm Reduction Journal 16: 43.

[20] Lea, T., et al. (2020). “Psychedelic Microdosing: A Subreddit Analysis.” Journal of Psychoactive Drugs 52(2): 101-112.

[21] Marschall, J., et al. (2024). “A Rapid Review of Low Doses of LSD and Psilocybin.” Neuroscience & Biobehavioral Reviews 156: 105491.

[22] Prochazkova, L., et al. (2018). “Exploring the effect of microdosing psychedelics on creativity in an open-label natural setting.” Psychopharmacology 235(12): 3401-3413.

[23] Yanakieva, S., et al. (2019). “The effects of microdose LSD on time perception: a randomised, double-blind, placebo-controlled trial.” Psychopharmacology 236(4): 1159-1170.

[24] Bershad, A.K., et al. (2019). “Acute Subjective and Behavioral Effects of Microdoses of Lysergic Acid Diethylamide in Healthy Human Volunteers.” Biological Psychiatry 86(10): 792-800.

[25] De Wit, H., et al. (2022). “Open-label, randomized study of the effects of acute MDMA on socio-emotional processing.” Journal of Psychopharmacology 36(3): 285-298.

[26] Szigeti, B., et al. (2021). “Self-blinding citizen science to explore psychedelic microdosing.” eLife 10: e62878.

[27] Marschall, J., et al. (2022). “Psilocybin microdosing does not affect emotion-related symptoms and processing: A preregistered field and lab-based study.” Journal of Psychopharmacology 36(1): 97-113.

[28] Szigeti, B., et al. (2023). “Weak blinding and activated expectancy bias can lead to false-positive findings in placebo-controlled trials.” Nature Mental Health 1(6): 410-419.

[29] Polito, V. & Stevenson, R.J. (2019). “A systematic study of microdosing psychedelics.” PLoS ONE 14(2): e0211023.

[30] Hutten, N.R.P.W., et al. (2020). “Subjective and autonomic nervous system effects of intravenous mescaline in a randomized, placebo-controlled trial.” Psychopharmacology 237: 3653-3661.

[31] Sessa, B. (2008). “Can psychedelics have a role in psychiatry once again?” The British Journal of Psychiatry 193(6): 451-452.

[32] Girn, M., et al. (2022). “Serotonergic psychedelic drugs LSD and psilocybin reduce the hierarchical differentiation of unimodal and transmodal cortex.” NeuroImage 256: 119220.

[33] Mason, N.L., et al. (2019). “Me, myself, bye: regional alterations in glutamate and the experience of ego dissolution with psilocybin.” Neuropsychopharmacology 44(9): 1594-1602.

[34] Family, N., et al. (2025). “Microdosing with psilocybin mushrooms: a double-blind placebo-controlled study.” Translational Psychiatry 15: 31.

[35] Kozin, M.S., et al. (2023). “Psilocybin, Cognitive Function, and Creativity: A Systematic Review.” European Journal of Neuroscience 57(7): 1118-1136.

[36] Galvão-Coelho, N.L., et al. (2021). “Changes in inflammatory biomarkers are related to the antidepressant effects of Ayahuasca.” Journal of Psychopharmacology 34(10): 1125-1133.

[37] Cavanna, F., et al. (2023). “Microdosing psychedelics in a naturalistic setting: Baseline characteristics, motivations, benefits, and challenges.” Frontiers in Psychiatry 14: 1071831.

[38] Murnane, K.S. (2018). “Serotonin 2A receptors are a stress response system: implications for post-traumatic stress disorder.” Behavioural Pharmacology 29(2-3): 151-162.

[39] Belleville, R.E., et al. (1956). “Development of tolerance to LSD in man.” Clinical Pharmacology and Therapeutics 1: 894-900.

[40] Nichols, D.E. (2004). “Hallucinogens.” Pharmacology & Therapeutics 101(2): 131-181.

[41] Wolbach, A.B., et al. (1962). “Comparison of psilocybin with mescaline, LSD-25 and placebo.” Psychopharmacologia 3(3): 219-223.

[42] Isbell, H., et al. (1961). “Cross-tolerance between LSD and psilocybin.” Psychopharmacologia 2(3): 147-159.

[43] González-Maeso, J., et al. (2007). “Hallucinogens recruit specific cortical 5-HT₂A receptor-mediated signaling pathways to affect behavior.” Neuron 53(3): 439-452.

[44] Lea, T., et al. (2020). “Perceived outcomes of psychedelic microdosing as self-managed therapies for mental and substance use disorders.” Psychopharmacology 237(5): 1521-1532.

[45] United Nations Office on Drugs and Crime (UNODC). (2021). World Drug Report 2021.

[46] Oregon Health Authority. (2023). Oregon Psilocybin Services.

[47] European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). (2022). Netherlands Country Drug Report 2022.

[48] Hughes, C.E. & Stevens, A. (2010). “What can we learn from the Portuguese decriminalization of illicit drugs?” The British Journal of Criminology 50(6): 999-1022.

[49] Beug, M.W. & Bigwood, J. (1982). “Psilocybin and psilocin levels in twenty species from seven genera of wild mushrooms in the Pacific Northwest, U.S.A.” Journal of Ethnopharmacology 5(3): 271-285.

[50] Erowid.org. (2020). “LSD Dosage.” LSD Vault.

[51] Suzuki, J., et al. (2014). “Toxicities associated with NBOMe ingestion—a novel class of potent hallucinogens: a review of the literature.” Psychosomatics 55(2): 129-135.

[52] Malcolm, B. & Thomas, K. (2021). “Serotonin toxicity of serotonergic psychedelics.” Psychopharmacology 239: 1881-1891.

[53] Johnson, M.W., et al. (2008). “Human psychopharmacology and dose-effects of salvinorin A, a kappa opioid agonist hallucinogen present in the plant Salvia divinorum.” Drug and Alcohol Dependence 115(1-2): 150-155.

[54] Carbonaro, T.M., et al. (2016). “Survey study of challenging experiences after ingesting psilocybin mushrooms: Acute and enduring positive and negative consequences.” Journal of Psychopharmacology 30(12): 1268-1278.

[55] Halpern, J.H. & Pope, H.G. (2003). “Hallucinogen persisting perception disorder: what do we know after 50 years?” Drug and Alcohol Dependence 69(2): 109-119.

[56] Rothman, R.B., et al. (2000). “Evidence for possible involvement of 5-HT₂B receptors in the cardiac valvulopathy associated with fenfluramine and other serotonergic medications.” Circulation 102(23): 2836-2841.

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