For nearly 3,000 years, the Eleusinische Mysteriën stood at the heart of spiritual life in the ancient Greek world — secretive, sacred, and fiercely protected. Initiates swore never to reveal what they experienced. Even powerful Romans, including emperors, traveled to participate. And yet, the central rite remains one of history’s most enduring enigmas.
Now, a new scientific study has reignited one of the most provocative theories in psychedelic scholarship. That priestesses of the Mysteries may have administered a psychoactive brew derived from ergot fungus to induce visionary states.
Published February 13 in Wetenschappelijke rapporten, the research explores whether ancient Greeks could have transformed toxic ergot into a psychedelic preparation using only technology available in antiquity. While the findings suggest it was chemically possible, experts caution that feasibility does not equal historical proof.
Let’s step into the ritual firelight.
The Psychedelic Eleusis Theory, Revisited
The idea that the Eleusinian Mysteries involved hallucinogens isn’t new. It gained widespread attention in 1978 with the publication of The Road to Eleusis: Unveiling the Secret of the Mysteries by author Gordon Wasson, classicist Carl Ruck (a co-author of the new study), and chemist Albert Hofmann. Psychonauts will recognise the same Hofmann who first synthesized LSD from an ergot derivative in 1938 and famously experienced its effects in 1943.
Their hypothesis? That the sacred drink consumed during the Mysteries (bekend als kykeon) may have contained psychoactive compounds derived from ergot, a fungus that grows on grains like barley.
But critics pointed out a major flaw: ergot is dangerous. In its natural state, it can cause ergotism — a condition associated with convulsions, gangrene, and mass poisoning.
“The central question was whether toxic ergot could realistically have been processed into something psychoactive but not lethal using methods available in antiquity." Said Evangelos Dadiotis, a pharmaceutical scientist at the University of Athens, in an email to Live Science. “We used a simple lye [sodium hydroxide] preparation made from water and ash, a technology well known in the ancient world.”
In other words: could ancient priestesses have detoxified ergot without modern chemistry?
Turning Poison into Vision
The research team experimented with Claviceps purpurea, the ergot fungus that infects cereal crops. They used an alkaline solution made from wood ash and water. This substance would have been readily available in ancient Greece. With this, they treated the fungus over time.
The result? The toxic proteins broke down, while non-toxic byproducts remained — including lysergic acid amide (LSA), a naturally occurring compound chemically related to LSD. LSA is less potent than LSD, but it can produce psychoactive effects and serves as a precursor in its synthesis.
“Nobody had shown before that ergot could be made safe by treating it with lye,” Dadiotis explained. “Our study fills that gap … that experimental bridge is what was missing.”
In short, the team demonstrated chemical feasibility. With ancient tools and materials, it would have been possible to create a psychoactive preparation from ergot that was unlikely to cause lethal poisoning.
But possible doesn’t mean proven.
Inside the Eleusinian Mysteries
To understand why this theory captivates scholars of psychedelics and ancient religion alike, we need to look at the Mysteries themselves.
Originating in the town of Eleusis in ancient Greece, the Eleusinian Mysteries honored the goddess Demeter and her daughter Persephone (also called Kore). According to myth, Persephone was abducted by Hades and taken to the underworld, plunging Demeter into grief and causing the earth to wither. A compromise struck by Zeus allowed Persephone to return each year — a cycle symbolizing death and rebirth, winter and spring.
The rites unfolded twice annually: the “Lesser Mysteries” in spring and the “Greater Mysteries” in autumn. They involved sacred processions, ritual sea bathing, animal sacrifice, days of fasting — and finally, the drinking of kykeon, a barley-based beverage flavored with herbs.
What happened after that remains deliberately obscure.
Initiates — known as mystai — reported profound, life-altering experiences. The secrecy was so absolute that breaking it could result in death. Even Roman emperors, including Augustus, sought initiation as the cult spread through the Roman Empire via religious syncretism.
Was kykeon simply symbolic? Or was it psychoactive?
Mint, Barley… and Ergot?
Dadiotis and his colleagues propose that detoxified ergot extract may have been added to the kykeon. They also point to earlier findings: in 2002. Researchers reported traces of psychoactive compounds in a ceremonial vase from an Eleusinian site in Spain, as well as in the hardened dental plaque of an individual buried there.
The traditional kykeon included barley and herbs — notably pennyroyal (Mentha pulegium), a pungent mint. Dadiotis suggests this aromatic herb could have masked the bitter taste of ergot extracts.
If true, the result may have been a ritual drink capable of inducing altered states. These experiences were perhaps interpreted as divine revelation within the context of Demeter and Persephone’s mythic drama.
It’s an alluring possibility. But not everyone is convinced.
Chemical Feasibility vs. Historical Proof
Sharday Mosurinjohn, a religious studies scholar at Queen’s University in Ontario who was not involved in the study, offers a measured response.
“The new study is an interesting and technically careful piece of analytical chemistry,” she told Live Science in an email.
“What it demonstrates is chemical feasibility within a plausible ancient technological context,” she said — but emphasized that “chemical feasibility is not historical proof.”
The research does not show that ancient Greeks actually used this method, nor that initiates consumed psychoactive doses during the Mysteries. It simply demonstrates that such a process was possible using ancient tools.
And when it comes to secret rites designed to leave no trace, that may be as close as we ever get.
Why This Still Matters in Psychedelic Research
Beyond the historical intrigue, the study touches on something bigger: the long human relationship between psychedelics, spirituality, and transformation.
Modern psychedelic science continues to explore how substances that interact with serotonin 2A receptors influence perception, meaning-making, and mystical experience. If ancient Greeks intentionally harnessed ergot’s psychoactive properties, it would suggest a sophisticated understanding of plant (and fungal) medicine embedded within ritual and myth.
Whether or not the Eleusinian kykeon was psychedelic, the conversation itself highlights a powerful truth: altered states of consciousness have likely played a role in religious and cultural evolution for millennia.
And the Mysteries remain just that — mysterious.
Perhaps fittingly, the secret of Eleusis may never be fully revealed. But thanks to modern chemistry and renewed interest in psychedelic history, we’re inching closer to understanding how ancient Greeks might have blended fungus, faith, and philosophy into one of the most enduring spiritual traditions of the classical world.
