A Brief History of Microdosing: From Stoned Apes to the Modern Revival

The long story of how humans came to know about psilocybin mushrooms — from prehistoric ritual use through the 1960s research era and the modern microdosing revival.

By The Microdose Movement · April 10, 2026

The practice of taking small intentional doses of psilocybin mushrooms is older than the word “microdose” by a very long time. The phrase itself is recent. The relationship between humans and these fungi is older than written language, older than agriculture, older than the cities the modern world was built on.

This article walks through the long story — from prehistoric ritual use to the laboratory isolation of psilocybin to the modern revival of intentional sub-perceptual dosing. It is not exhaustive. It is the version that helps explain why the practice exists in the form it does today.

The deep history: psilocybin and human evolution

Psychedelic mushrooms have been growing on Earth for far longer than humans have been around to find them. The genus Psilocybe alone contains over 200 species, distributed across every continent except Antarctica. Wherever humans evolved, psilocybin-producing fungi were almost certainly present, growing in the dung of grazing animals and in decaying vegetation.

The most provocative theory about this relationship is the Stoned Ape Hypothesis, proposed by ethnobotanist Terence McKenna in his 1992 book Food of the Gods. McKenna argued that early humans, foraging in the African savanna, would have encountered psilocybin mushrooms growing in cattle dung and consumed them as part of their general food gathering. He hypothesized that the cognitive effects of these mushrooms — heightened perception, language development, novel pattern recognition — could have accelerated human cognitive evolution and contributed to the rapid increase in brain size that distinguishes Homo sapiens from earlier hominids.

The Stoned Ape Hypothesis is widely considered speculative by mainstream evolutionary biology. It is not supported by direct archaeological evidence, and the mechanism McKenna proposed has not been formally tested. But it is also not refuted. The geographic correlation between early human habitats and psilocybin-bearing fungi is real. And the theory has had enormous cultural influence on how the modern psychedelic community understands the human-mushroom relationship.

What is more solidly documented is the use of psilocybin mushrooms in ancient ceremonial contexts. Archaeological evidence from rock art in the Sahara dating to around 7000 BCE depicts figures holding what appear to be mushrooms, and similar imagery has been found in prehistoric sites in Spain, Mexico, and elsewhere. The Aztec, Mixtec, and Mazatec peoples of Mesoamerica used psilocybin mushrooms in religious ceremony for at least 3,000 years before European contact.

These were not microdoses in any modern sense. They were full ceremonial doses, taken in structured ritual contexts, often consumed by religious specialists who guided others through visionary experiences. But the relationship was old, deep, and continuous in a way the modern revival is only beginning to recover.

The Spanish suppression and the long underground

When Spanish missionaries arrived in central Mexico in the 16th century, they encountered the indigenous use of psilocybin mushrooms and immediately classified it as devil worship. The Catholic Church banned the practice. The Inquisition prosecuted curanderos who continued the ceremonies. For roughly four hundred years, the use of teonanácatl — the Aztec name for psilocybin mushrooms, meaning “flesh of the gods” — went underground.

It did not disappear. In remote mountain regions of Oaxaca and Guerrero, Mazatec, Mixtec, and other indigenous communities continued the practice in secret, passing the knowledge from curandera to curandera across generations. By the time the modern world rediscovered these mushrooms in the 20th century, the lineage had been preserved by a small number of elders living in places the Spanish authorities had never fully reached.

Maria Sabina was one of those elders. Her decision to share a velada ceremony with the American banker R. Gordon Wasson in 1955 reopened the door between the indigenous tradition and the modern world — and triggered the chain of events that led to everything that followed.

Albert Hofmann and the laboratory isolation

In 1958, the Swiss chemist Albert Hofmann received a sample of dried psilocybin mushrooms from R. Gordon Wasson. Hofmann was already famous in chemistry circles for having synthesized LSD in 1938 and for having discovered its psychedelic properties accidentally five years later when he absorbed a tiny amount through his skin. He was the right person to receive Wasson’s mushroom samples, and he set to work isolating the active compound.

By 1959, Hofmann had isolated and synthesized psilocybin, the molecule that makes the mushrooms psychoactive. He published his findings in the journal Experientia the same year. Sandoz Pharmaceuticals, where Hofmann worked, began producing synthetic psilocybin under the brand name Indocybin for psychiatric research throughout the 1960s.

For the first time in history, psilocybin existed as a pure, standardized, dose-controlled compound that researchers anywhere in the world could request and study. The implications were enormous. Psilocybin had moved from the mountains of Oaxaca to the formal apparatus of Western pharmacology in less than a decade.

Hofmann’s work also produced the related compound psilocin, the active metabolite that the body converts psilocybin into. The full chemistry is covered in our science page on psilocybin vs psilocin.

The 1960s research era

The decade from roughly 1960 to 1970 was the first golden age of psychedelic research. Psilocybin and LSD were both legal, both available to researchers through Sandoz, and both being studied at major universities around the world.

A few of the most important projects:

The Harvard Psilocybin Project (1960–1962). Founded by Timothy Leary and Richard Alpert (later Ram Dass) at Harvard’s Center for Research in Personality, the project conducted formal studies of psilocybin’s effects on creativity, religious experience, and rehabilitation. The project became famous, then notorious, then was shut down by the university in 1963 when it became clear that the protocols had drifted from formal research into something more like personal exploration. The shutdown of the Harvard project is one of the cultural turning points in psychedelic history.

The Concord Prison Experiment (1961–1963). Leary’s team gave psilocybin to prisoners as part of a rehabilitation study. Initial reports suggested significant reductions in recidivism. Later reanalysis of the data was less optimistic, but the study established that psilocybin could be used in serious therapeutic contexts.

The International Foundation for Advanced Study (1961–1965). A Menlo Park, California group led by Willis Harman and including a young James Fadiman, who would later become one of the founders of the modern microdosing protocol. The IFAS conducted some of the first formal studies of psychedelics for creative problem-solving. Their 1966 paper, Psychedelic Agents in Creative Problem-Solving: A Pilot Study, gave moderate doses of mescaline to scientists and engineers stuck on technical problems and documented breakthrough results. Several of the breakthroughs led to patented inventions.

The Good Friday Experiment (1962). Conducted at Boston University by Walter Pahnke, this study gave psilocybin to theology students during a Good Friday service to test whether the drug could produce genuine mystical experiences. The students who received psilocybin reported significantly more profound religious experiences than the control group. A long-term follow-up decades later showed many of them still considered the experience among the most meaningful events of their lives.

By the late 1960s, more than a thousand academic papers on psychedelic research had been published. Then it all stopped.

The Controlled Substances Act and the dark age

In 1970, the United States Congress passed the Controlled Substances Act, which classified psilocybin as a Schedule I substance — defined as having “no currently accepted medical use” and “high potential for abuse.” LSD was scheduled the same way. So was MDMA, peyote, and most other psychedelic compounds.

The Schedule I designation effectively shut down legal research. Researchers could still apply for special exemptions, but the bureaucratic burden was so high that almost no one tried. The 1,000+ papers of the 1960s slowed to a trickle. For most of the next thirty years, psilocybin research in the United States and most of Europe was functionally dead.

The full story of how this happened — and what it cost the field — is covered in The Suppressed Decade.

The modern revival

The revival began in the early 2000s with a single brave research team at Johns Hopkins University. Roland Griffiths, a psychopharmacologist with a long career studying caffeine and other legal compounds, became interested in whether psilocybin could be studied formally again. In 2006 he published a landmark paper titled “Psilocybin Can Occasion Mystical-Type Experiences Having Substantial and Sustained Personal Meaning and Spiritual Significance.” It was the first major modern study of psilocybin in healthy volunteers and it was the proof that careful research was possible again.

The paper opened the door. Other research groups followed. The Heffter Research Institute, MAPS, NYU Langone, and most importantly the team at Imperial College London led by Robin Carhart-Harris and David Nutt began conducting modern clinical trials of psilocybin for depression, end-of-life anxiety, addiction, and other conditions. The results were strong. The science was getting harder to ignore.

Meanwhile, in 2010, James Fadiman — the same Fadiman who had been part of the IFAS in the 1960s — published The Psychedelic Explorer’s Guide, which included a chapter on what he called “sub-perceptual” dosing. The book formalized what would become known as the Fadiman Protocol and gave the modern microdosing movement its first widely-distributed protocol. Fadiman began collecting volunteer reports through a website. Over the next decade he gathered thousands of self-reported experiences from microdosers all over the world.

By 2018 the practice had crossed into the cultural mainstream. Newspaper articles, podcasts, conferences, and books were everywhere. By 2024 an estimated 9.5 million American adults had tried microdosing in some form. The practice that began with Mazatec curanderos and went through Hofmann’s laboratory had become a recognizable part of the wellness landscape.

The story is still being written. The science is catching up. The cultural conversation has shifted. The institutions that suppressed this work for decades are quietly reversing position. And every modern microdoser, whether they know it or not, is participating in a tradition that traces back through Maria Sabina, through prehistoric rock art, and probably through the long uncertain centuries of human-mushroom relationship that the Stoned Ape Hypothesis tried to name.

What this history asks of us

A few things worth carrying.

The medicine has a lineage. Whatever you do with a microdose today, you are participating in something with deep roots. Treat the relationship accordingly.

The research was always there. The 1960s work was real. The 1990s and 2000s revival did not invent psychedelic science. It recovered what had been suppressed. Reading the historical literature is one way to remember that the modern field is a return, not an origin.

The suppression was political, not scientific. Psilocybin was scheduled because of cultural anxiety, not because the evidence justified it. Knowing this matters for how you talk about the medicine in the present and how you understand the slow process by which it is becoming legitimate again.

The communities that carried this knowledge through the dark deserve attention. This is the central point of the Maria Sabina story and the indigenous wisdom article. Without those communities, none of the modern revival would be possible. Without acknowledging them, the modern revival becomes another act of extraction.

Sources and Further Reading

McKenna, T. (1992). Food of the Gods: The Search for the Original Tree of Knowledge. Bantam.
Schultes, R. E., & Hofmann, A. (1979). Plants of the Gods: Origins of Hallucinogenic Use. McGraw-Hill.
Hofmann, A. (1980). LSD: My Problem Child. McGraw-Hill.
Pollan, M. (2018). How to Change Your Mind: What the New Science of Psychedelics Teaches Us About Consciousness, Dying, Addiction, Depression, and Transcendence. Penguin.
Griffiths, R. R., et al. (2006). “Psilocybin can occasion mystical-type experiences having substantial and sustained personal meaning and spiritual significance.” Psychopharmacology, 187(3), 268–283.
Fadiman, J. (2011). The Psychedelic Explorer’s Guide: Safe, Therapeutic, and Sacred Journeys. Park Street Press.

The Microdose Movement is an educational community, not a medical provider. Nothing in this article is medical advice.