Dennis McKenna — An Ethnopharmacologist on Hallucinogens, Sex-Crazed Cicadas, The Mushrooms of Language, BioGnosis, and Illuminating Obscure Corners (#592)

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“To make the world comprehensible, you have to selectively filter what gets in. You inhabit this filtered—you could almost use the word curated—version of reality. Otherwise, it would just be a blooming, buzzing confusion you wouldn’t be able to navigate. And then you can take a psychedelic. You can disable those mechanisms. You can disable this default mode mechanism, open the gates of the reducing valve, and that can be very beneficial in terms of helping you get outside of your reference frame.”

— Dennis McKenna

Dennis McKenna (@DennisMcKenna4) has spent more than 40 years researching the interdisciplinary study of Amazonian ethnopharmacology and plant hallucinogens. He has conducted extensive ethnobotanical fieldwork in the Peruvian, Colombian, and Brazilian Amazon.

His doctoral research at the University of British Columbia focused on the ethnopharmacology of ayahuasca and oo-koo-he, two tryptamine-based hallucinogens used by indigenous peoples in the Northwest Amazon.

He is a founding board member of the Heffter Research Institute and was a key organizer and participant in the Hoasca Project, the first biomedical investigation of ayahuasca used by the UDV, a Brazilian religious group. He is the younger brother of Terence McKenna.

From 2000 to 2017, he taught courses on ethnopharmacology as well as Plants in Human Affairs at the Center for Spirituality and Healing at the University of Minnesota. In 2019, in collaboration with colleagues, he incorporated a nonprofit, the McKenna Academy of Natural Philosophy. Currently, the Academy has several projects underway, with the most immediate being preparations for an upcoming conference in the UK May 23rd–26th, ESPD55, which will cover a wide range of topics related to psycho-ethnopharmacology and feature an exclusive, pre-release screening of the McKenna Academy’s first short documentary, BioGnosis, Bridges to Ancestral Wisdom.

Dennis emigrated to Canada in the spring of 2019 with his wife Sheila and now resides in Abbotsford, British Columbia.

Please enjoy!

Listen to the episode on Apple Podcasts, Spotify, Overcast, Podcast Addict, Pocket Casts, Castbox, Google Podcasts, Amazon Music, or on your favorite podcast platform. You can watch the interview on YouTube here.

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The transcript of this episode can be found here. Transcripts of all episodes can be found here.

#592: Dennis McKenna — An Ethnopharmacologist on Hallucinogens, Sex-Crazed Cicadas, The Mushrooms of Language, BioGnosis, and Illuminating Obscure Corners

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What was your favorite quote or lesson from this episode? Please let me know in the comments.


Want to hear the last time Dennis McKenna was on this show? Give a listen to our conversation here, in which we discussed the psychedelic ecosystem, cultural back stories of now-common medicinal compounds, exploring the mysteries of ayahuasca with scientific curiosity, how the experiment at La Chorrera (as chronicled in brother Terence McKenna’s True Hallucinations) went off the rails, new thoughts on the stoned ape theory, and much more.

#523: Dennis McKenna — The Depths of Ayahuasca: 500+ Sessions, Fundamentals, Advanced Topics, Science, Churches, Learnings, Warnings, and Beyond


  • Connect with Dennis McKenna:

Blog | Twitter | Facebook | Instagram

  • Connect with McKenna Academy:

Website | Donate | Twitter | Facebook | Instagram | YouTube

  • ESPD 55 | McKenna Academy
  • BioGnosis: Bridges to Ancestral Wisdom | McKenna Academy
  • Dennis McKenna — The Depths of Ayahuasca: 500+ Sessions, Fundamentals, Advanced Topics, Science, Churches, Learnings, Warnings, and Beyond | The Tim Ferriss Show #523
  • The Brotherhood of the Screaming Abyss: My Life with Terence McKenna by Dennis McKenna | Amazon
  • Heffter Research Institute
  • The Hoasca Project | MAPS
  • Banisteriopsis Caapi | Wikipedia
  • Understanding MAO Inhibitors: Types, Side Effects, and More | Healthline
  • Breaking Down the Brew: Examining the Plants Commonly Used In Ayahuasca | Psychedelic Times
  • What is a Dieta? |
  • Cultural Awareness: Understanding Curanderismo | ACA
  • The Curare Plant: A Cure All, or Kill All? | The Evergreen State College
  • Set and Setting: Why Preparation Matters | DoubleBlind
  • Mike Tyson on Smoking DMT: ‘Do You Understand the Toad?’ | The Art of Conversation with Dan Le Batard
  • Tetrahydroharmine – Mysterious Alkaloid of the Banisteriopsis Caapi | Gaia Store
  • Psilocybe Cubensis | Wikipedia
  • Ketamine Infusions vs. Intramuscular Ketamine Injections | SKI
  • Cannabinoid Receptors in the Central Nervous System: Their Signaling and Roles in Disease | Frontiers in Cellular Neuroscience
  • Brain Activity of Anandamide: A Rewarding Bliss? | Acta Pharmacologica Sinica
  • How Opioid Drugs Activate Receptors | National Institutes of Health
  • Receptors & Ligands | 2-Minute Neuroscience
  • DMT Is in Your Head, but It May Be Too Weird for the Psychedelic Renaissance | Scientific American Blog Network
  • John Chavez: How To Create DMT Naturally Inside Your Body | Wellness Force Media
  • Meet LUCA, the Ancestor of All Living Things | The New York Times
  • Signal Transduction Pathways | Bozeman Science
  • These Fungi Drug Cicadas with Psilocybin or Amphetamine to Make Them Mate Nonstop ⁠— The Insects Keep At It Even If Chunks of Their Abdomens Fall Off | Science News
  • Massospora Cicadina | Wikipedia
  • Khat: Effects, Risks, and How to Get Help | Verywell Mind
  • After This Fungus Turns Ants Into Zombies, Their Bodies Explode | The New York Times
  • Cordyceps | Wikipedia
  • Parasite Makes Mice Lose Fear of Cats Permanently | Nature
  • LSD May Offer Viable Treatment for Certain Mental Disorders | Neuroscience News
  • Hallucinogens and Culture by Peter T. Furst | Amazon
  • The Mushrooms of Language by Henry Munn | The Psychedelic Library
  • The Concept of Logos | Classical Wisdom Weekly
  • What Is It Like To Have Synesthesia? | The Royal Institution
  • Trippy Research: Chemically-Induced Synesthesia | Technology Networks
  • Synesthesia on Psychedelics | Vice
  • Understanding the Default Mode Network | Verywell Health
  • Professor Donald Hoffman — The Case Against Reality, Beyond Spacetime, Rethinking Death, Panpsychism, QBism, and More | The Tim Ferriss Show #585
  • Aldous Huxley: The Reducing Valve Theory | Nexus Void
  • 50 Years Ago, an Apollo 14 Astronaut Played Golf on the Moon. Here’s the inside Story. | Space
  • Consciousness: Edgar Mitchell’s Samadhi in Deep Space | Hinduism Today
  • Overview Effect and the Experience of Savikalpa Samadhi of the Astronauts | Technology of the Heart
  • Institute of Noetic Sciences (IONS)
  • What is the Mystical Experience Questionnaire? | Psychedelic Science Review
  • Bicycle Day by Brian Blomerth | Amazon
  • The Mind of a Mnemonist: A Little Book about a Vast Memory by Aleksandr R. Luria | Amazon
  • Rain Man | Prime Video
  • Brainman: Inside the Mind of an Autistic Savant | The Marginalian
  • 5 Mind-Blowing Things Kim Peek Could Do That You Can’t | ABA
  • The Ethnopharmacologic Search for Psychoactive Drugs: Reflections on a Book that Changed My Life by Dennis MeKenna | American Botanical Council
  • Ethnopharmacologic Search for Psychoactive Drugs (Vol. 1 & 2): 50 Years of Research Edited by Dr. Dennis McKenna, PhD; Professor Sir Ghillean T. Prance; Professor Wade Davis, PhD; Benjamin De Leonen | Amazon
  • ESPD 50 | Vimeo
  • Indigenous Communities in Post-FARC Colombia Struggle to Destigmatize Sacred Coca Leaf | Mongabay
  • Kratom (Mitragyna Speciosa): Recent Advances in Understanding the Chemistry, Pharmacology, and Human Uses | ESPD 55
  • Integral Projection Models: A Road Map for Sustainable Ayahuasca Production | ESPD 55
  • Psychedelic Fauna for Psychonaut Hunters | ESPD 55
  • A History of Psychoactive Plants and Fungi in Chinese Medicine | ESPD 55
  • Farming Psychedelics and Other Tryptamine Medicines from Marine Sponges: Yield Enhancing Lessons from Psilocin | ESPD 55
  • The Harpy’s Gift and the Jaguar’s Curse: Hunting Medicines Among the Matsigenka | ESPD 55
  • Ethnopharmacology and Phytochemical Profiling of Huachuma | ESPD 55
  • Expanding Evidence of Anadenanthera in the Pre-Columbian Andes: Identifying Depictions of Anadenanthera in the Iconographic Records of Cupisnique, Paracas and Nazca Cultures | ESPD 55
  • Creation of an Ethnopharmacological Plant Repository in Southern Brazil. Presentation of a Collaborative Project to Establish a Collection of Sacred Psychoactive Medicinal Plants at Wasiwaska Research Center in Florianópolis, Brazil | ESPD 55
  • Chemically-Induced Otherworldly Experiences of Zoroastrians in Iran | ESPD 55
  • Huachuma Collective | Instagram
  • International Society of Environmental Relationship And Sustainability (ISERS)
  • What Near-Death Experiences Reveal about the Brain | Scientific American
  • Near-Death Experiences Evidence for Their Reality | Missouri Medicine
  • Hamlet’s Soliloquy | Monologue Archive
  • Can Psychedelics Help Make Dying Easier? | Rolling Stone
  • Interview: Celebrity Psychonaut Dennis McKenna | NAILED Magazine
  • Pharmahuasca: Can a Chemical Ayahuasca Alternative Compare? | Khapi
  • An Urgent Plea to Users of Psychedelics: Let’s Consider a More Ethical Menu of Plants and Compounds | Tim Ferriss
  • The Native American Church and Peyote Ceremonies | Learn Religions
  • Indigenous Peyote Conservation Initiative
  • Mesoamerican Cosmovision | Wikipedia
  • Lophophora Williamsii (Mescal, Mescal Buttons, Peyote) | North Carolina Extension Gardener Plant Toolbox
  • The English Diggers (1649-50) | The Digger Archives
  • Failed ‘Utopias’ Throughout History | Vice
  • Scarface | Prime Video
  • What Is a Bodhisattva? | Tricycle
  • In ‘Stoned Ape’ Theory, Consciousness Has Roots in Psilocybin | Inverse
  • Cannabis 101: Educational Information & Resources | Leafly
  • Marijuana Is 67,200 Times Stronger than It Used to Be (According to the Media) | Cracked
  • Difference Between Hashish And Marijuana? | Sunrise House Treatment Center
  • Weed Rituals: A Cross-Cultural Connection to Calm | Leafly
  • Amazonian Digital Herbarium Project | Botanical Dimensions
  • A Plant Whose Virtues Remain Undiscovered | Mother Earth News


  • How Dennis and his brother Terence tuned in to “vegetable television” with the addition of an ayahuasca ingredient to their regular consumption of mushrooms and cannabis, and why even the components of tried-and-true ayahuasca are in constant flux depending on who’s making it. [07:39]
  • Why is it that psychoactive drugs don’t always work — even in people who usually feel their effects — and what keeps us from finding out through controlled studies? [13:51]
  • As much as Dennis has experimented with adding and subtracting ingredients to various psychoactive admixtures, he’s come to believe it’s best to avoid combinations if possible. There are often alternative ways to dial the effects of these substances up or down as desired. [21:43]
  • Why would we have cannabinoid, opiate, and other molecular receptors in our brains unless we’re designed to consume these substances from external sources? [29:45]
  • Tales of terror from the world of psilocybin cicadas, cordyceps zombies, and toxoplasmic rodents. [36:34]
  • Dennis shares his thoughts on psychedelics as a potential treatment for dyslexia and other language-based disorders. [42:20]
  • What happened to Apollo 14 astronaut Edgar Mitchell after having his savikalpa samadhi experience — a mystic glimpse beyond the self into the true nature of things? Does Dennis believe current psychedelic pioneers are misguided in downplaying the mystical experiences certain compounds bring out in people? [50:18]
  • For anyone curious about Albert Hofmann’s discovery of LSD, Dennis recommends the graphic novel Bicycle Day by Brian Blomerth. [53:48]
  • My recommended resources for learning more about the perceptual phenomenon of synesthesia. [54:58]
  • What ESPD 55 entails: its history, its itinerary, and how you can participate even if you can’t physically make it to the conference in the UK from May 23rd to the 26th. [56:51]
  • How does Dennis relate to mortality and the inevitability of death? [1:08:54]
  • What is BioGnosis? [1:11:56]
  • How does Dennis feel about synthetic substitutes for psychedelic compounds that have been traditionally harvested from natural — and often endangered — sources? What adaptations might groups who see these plants as sacred have to make to ensure that some of them don’t go extinct? [1:14:16]
  • Most communities of any size eventually have to deal with in-fighting and power grabs from a certain element, and the psychedelic community is no exception. Can Dennis imagine any solutions to this unfortunate reality? [1:25:31]
  • What would Dennis choose if he could only partake of three psychoactive substances for the rest of his life? [1:35:02]
  • The pros and cons of cannabis consumption and its methods of delivery, and how modern strains can induce experiences akin to psychedelics. [1:36:38]
  • What we can expect from an upcoming second edition of The Brotherhood of the Screaming Abyss, The BioGnosis Project (and its first associated documentary (to be screened at ESPD 55), virtualizing the Herbarium in Iquitos, and other parting thoughts. [1:42:46]


“There is no such thing as a standardized mixture of ayahuasca because each preparation is as different as the practitioners that prepare it. It has their idiosyncratic stamp on it.”

— Dennis McKenna

“I think psychedelics are our co-evolutionary partners. I think they help us become better people, but you have to work at it. Like any kind of spiritual, moral, ethical development, you’re not going to make it unless you actually try and believe in it.”

— Dennis McKenna

“A lot of these plants are not very well investigated from a scientific point of view, but it’s an empirical science. And the point is in some ways these practitioners, shamans, curanderos, they’re really scientists in a certain sense. They’re experimental about it and they don’t hesitate to say, ‘Well, what if I take this and mix it with that? What’s going to happen? How is that going to change the effect?’ Those who survive this process make discoveries, but there is the potential to take the wrong things.”

— Dennis McKenna

“Nature is drenched in DMT.”

— Dennis McKenna

“Long before I heard of default mode network, I was calling it the reality hallucination. Effectively, we live in a hallucination. We live in an artificial world reality that our brains construct. And it must reflect whatever’s out there, because we’re not wandering around stepping in front of buses and things like that. So it does map to reality in some ways, but it’s actually an impoverished version of reality. A lot of what the brain does is filter things out.”

— Dennis McKenna

“To make the world comprehensible, you have to selectively filter what gets in. You inhabit this filtered—you could almost use the word curated—version of reality. Otherwise, it would just be a blooming, buzzing confusion you wouldn’t be able to navigate. And then you can take a psychedelic. You can disable those mechanisms. You can disable this default mode mechanism, open the gates of the reducing valve, and that can be very beneficial in terms of helping you get outside of your reference frame.”

— Dennis McKenna

“I have nothing against synthetics. I think synthetics have their place. Like I like to tell people, synthetics are made by all-natural organic chemists. They come from nature, ultimately.”

— Dennis McKenna

“It’s hard to find consensus. Everybody’s got a different idea and we have a hard time listening to each other.”

— Dennis McKenna

“I know lots of people who take lots of psychedelics. They’re still assholes. It’s not a cure for that.”

— Dennis McKenna

“It’s just tough to be a kind and gentle and insightful and wise person. That’s kind of what we’re here for, though, I think.”

— Dennis McKenna

“We’re midway between the apes and the angels right now.”

— Dennis McKenna


The Tim Ferriss Show is one of the most popular podcasts in the world with more than 700 million downloads. It has been selected for “Best of Apple Podcasts” three times, it is often the #1 interview podcast across all of Apple Podcasts, and it’s been ranked #1 out of 400,000+ podcasts on many occasions. To listen to any of the past episodes for free, check out this page.

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