Ayahuasca—a foul-tasting hallucinogenic tea that can induce violent nausea and terrifying visions—is becoming trendy. A recent article in the "Fashion & Style" section of The New York Times notes that many people—including celebrities such as Lindsay Lohan and Sting—have turned to ayahuasca as a "catalyst for inner growth."

Ayahuasca is fascinating, for many reasons. Long consumed by Amazonian Indians, ayahuasca is brewed from two plants, one of which contains dimethyltryptamine, the only psychedelic known to occur naturally in the human body; in 1972, the Nobel laureate Julius Axelrod of the National Institutes of Health discovered DMT in human brain tissue, leading to speculation—never confirmed--that it plays a role in psychosis and other extreme mental states. (For more background on DMT and ayahuasca, see my 2010 column "DMT is in your head, but it may be too weird for the psychedelic renaissance.")

Normally DMT must be injected for its psychotropic effects to be experienced, because it is dissolved by the gut enzyme monoamine oxidase. But ayahuasca contains monoamine oxidase inhibitors that render the ingested DMT psychoactive. Ayahuasca “is an extremely potent hallucinogen which no one should ingest carelessly,” botanist Jim DeKorne warns in his 1994 book Psychedelic Shamanism.

Monoamine oxidase inhibitors can cause severe reactions when combined with foods such as cheese, beer, wine, yogurt, coffee and chocolate; with amphetamine-type compounds such as ephedrine and MDMA; and with selective serotonin re-uptake inhibitors, a class of antidepressants. The surest way to avoid these physiological side effects is to fast for twelve or more hours before consuming ayahuasca.

I drank ayahuasca in 1999, in a ceremony led by two scholars with expertise in ayahuasca. (This episode took place just two days after my interview of Alexander and Ann Shulgin, which I recently described on this blog.) What follows is an edited version of what I wrote about the experience in my 2003 book Rational Mysticism.

The sun was descending toward the Pacific when I turned off California's coastal highway and headed inland toward my ayahuasca rendezvous. My stomach was growling; on the advice of the session leaders, I had not eaten all day. The route led east through a redwood glade, swung back west and broke out onto a brown, treeless headland crisscrossed with wire fences. After passing a couple of dilapidated barns, I arrived at my destination, a fenced-off ranch perched on a gentle slope high above the Pacific. As I rumbled over a cattle guard and pulled up next to a half-dozen other cars in the driveway, I thought: Too late to turn back now.

Six of the nine people with whom I would spend this evening were already there. (I have changed their names to preserve their privacy). The two owners of this ranch were Allen, founder of a health-food company, who was genial, 50-ish, with receding hair; and Deborah, Allen’s wife and business partner, who had short blond hair and wide-set grey eyes. Although she welcomed me warmly, Deborah seemed faintly melancholy, as if distracted by some private grief.

The other four people present were willowy, blond Linda, who rented a guest house from Allen and Deborah; Nancy, Linda’s roommate, a firewoman with the build of a serious weight-lifter; Michael, thirty-ish, also an executive in the health-food business, with an Irish boxer’s face; and Brad, who had the sun-bleached hair and George Hamilton tan of an aging surfer.

About a half hour after I arrived, the final three members of our group showed up: Tony, who had dark hair and soulful, protuberant eyes; bearish, balding Kevin; and Blaed, Kevin’s twenty-something nephew, who had sharp, angular features and a goatee. Tony and Kevin, both scientists with extensive knowledge of psychedelics, were co-leaders of this session. They popped open the trunk of their car and unloaded plastic cups, a tape player, and sleeping bags; bags of food for breakfast the next morning; and a cooler containing several large, clear-plastic bottles filled with what looked like purple-brown spit: ayahuasca.

The sunset left the sky stained with bloody, Rothko-esque swaths. As night fell, the tension grew. Talking to my companions, I learned that this would be the first ayahuasca trip not only for me but also for Deborah, Nancy, Brad, and Blaed. At nine o’clock we headed out of the house. The sky was clear, emblazoned with stars and a nearly full moon. We walked a hundred yards or so from the house to a flat, grassy spot where Nancy and Linda had created a “sacred circle,” a patch of gravel ringed by fist-size stones. This was where we would spend the evening. At the center of the circle was an altar, a box covered with a multi-colored cloth.

We took our places around the circle, laying down blankets, sleeping bags, pillows. Tony told us to put our “sacred objects”—the items of personal significance that we were supposed to bring to the session--on the altar in the circle’s center. I took from my pocket the glossy black feather of a crow and put it on the altar, beside a vase of flowers, an owl feather, an amethyst crystal, a bongo, a leather rattle, and a tiny bust of Queen Nefertiti. Tony lit a bundle of sage and wafted the smoke around the site. “It’s for purification,” he said with an embarrassed grin.

Tony handed out rattles, which he said dispel negative thoughts; chanting or humming are also helpful. But after the ayahuasca takes effect, Tony added, we should refrain from speaking while in the sacred circle. If we want to talk, we should leave the circle, so as not to disturb the others. Tony also gave each of us a shiny, brand-new, steel bucket. Ideally, he advised, we should go to a nearby embankment to vomit, but if we can’t make it that far, we should throw up in the bucket. We will probably all get sick, Tony said, but that’s okay; vomiting has a therapeutic, purgative effect.

Tony told us that this ayahuasca, which he obtained from a Brazilian sect, was the best he had ever sampled. It had six times more DMT than the average batch of ayahuasca, according to a chemical analysis done by a friend of Tony’s. The men who gather the plants and make the brew usually do so while under ayahuasca’s influence. They claim that the spirit of ayahuasca guides them to the best plants and helps them prepare the brew properly; Tony had no reason to disbelieve them.

Members of the Brazilian church usually take 50 milliliters, about a quarter of a cup. But they need only a modest dose, Tony explained, because ayahuasca consumption leads to reverse tolerance; over time smaller amounts produce the same psychotropic effects. Tony was giving us 120 milliliters, because he wanted to be sure we have a strong, satisfying experience. Better to have too much ayahuasca, he said, than not enough; with smaller doses, you might merely get sick without experiencing any hallucinogenic effects.

Tony held up a rope woven of multi-hued strings, which he said symbolized the unity of our group. He asked each of us to tie a knot in the rope and say something, anything, to the rest of the group. Tomorrow morning we will untie our knots and share our thoughts again. As the rope passed around the circle, everyone expressed gratitude: to Tony and Kevin for bringing the ayahuasca and being our guides, to Allen and Deborah for making their home available for the ceremony, to Linda and Nancy for preparing this sacred circle. Linda reminded us that she would not be taking any ayahuasca; she was here to serve the rest of us.

A few people revealed what they hoped to accomplish this evening. Michael wanted to find ways to get closer to his family, including a brother from whom he was estranged. Allen hoped to come to terms with the recent death of his father. Kevin and his nephew Blaed were concerned about a relative who had cancer.

If anyone wanted to take a walk, Tony said, please tell him, Kevin, or Linda, so they could keep track of everybody. Grasping a plastic bottle of ayahuasca, he poured the stuff into a steel measuring cup and then into nine green plastic cups. There was plenty of ayahuasca to spare, he assured us. Anyone who feels no effects after an hour or so should ask for a 50 milliliter supplement then, or at any time during the night. Tony suggested that we all drink at the same time. Following his lead, we stood and faced each other, everyone except Linda holding a cup.

“Salud!” Tony exclaimed, and as one we quaffed our doses.

The ayahuasca tasted astonishingly foul, an unwholesome mixture of bitterness and rancid sweetness. I gagged, as did almost everyone else. Tony urged us to suppress our nausea for as long as possible, to give the ayahuasca time to take effect. Blaed said the ayahuasca tasted like stale dregs of stout. Dregs with cigarette butts in them, someone added.

The conversation died down. Some of the group remained standing; others sat or lay on their sleeping bags. I stood looking east at the hills, the stars, the moon. The Pleiades were diamond chips flung across a strip of gauze. A planet, Jupiter, someone said, blazed in the southern sky. A plane, or satellite, or something hurtled overhead. A star caught my eye, hovering twenty degrees above the horizon. It twinkled at the end of a long tube or tunnel, beaming its light across light years of vacuum here to me. Energy radiated from the star in a shifting snowflake pattern. Was this strange, or was I just paying closer attention than usual to an ordinary low-light visual effect? I couldn’t decide.

Tony turned on a tape recording made in a Peruvian rain forest. The yelps, hoots, howls, ululations, clicks, rattles mingled with local noises--crickets chirping, a dog barking, humans sighing, clearing their throats, grinding gravel under shoes or rear ends. The sounds had a muffled, reverberatory quality, as if we were all sealed within a cavernous metal tank. I felt weak-kneed, dizzy, probably just from hunger, I thought. I sat and closed my eyes.

At the bottom of a dark, radiant well shimmered a white shape, a vaguely heart-shaped manifold, slowly rotating. Definitely strange, I thought, not your ordinary rods-and-cones hallucination. The white manifold dissolved into an incalculably more complex scene, an iridescent, alien landscape vaguely reminiscent—some pedantic part of my brain remarked—of the paintings of the French surrealist Yves Tanguy. The landscape was populated with bizarre geometric objects--shards, scimitars, French curves, manifolds--simultaneously two- and three-dimensional and lacquered, glazed, suffused with achingly lovely colors.

The jungle sounds—the hoots and screams and hisses and rattles—grew ever more insistent, manic, urgent, and they seemed to inject energy into my visions, making them percolate and convect at an ever-more-furious rate. The forms shifted, tumbled, quivered, danced with a kind of mischievous intelligence. They were showing off, trying to stagger me with ever-more-ostentatious displays of otherworldly beauty: Look at this! Okay, now check this out! But that doesn’t compare to... this!

Overwhelmed, I opened my eyes. There were Deborah and Linda sitting across from me, bundled up in blankets. Silhouetted against the sky, they looked ancient, archetypal, like stoic Aztec women. There, to my immense relief, were the sky, the stars, the moon--altered, to be sure, phosphorescent plankton adrift in an opalescent sea, dewdrops in a cosmic spider’s web. But they were there, they were real, and I felt grounded, back in touch with the world of things.

But then this world too, grew strange. Flashes on the horizon, followed by ominous booms. What the hell was that? Thunder? Artillery fire? The beginning of the end? Real or hallucination? It was too much. I closed my eyes and the iridescent polygons rushed back at me with a vengeance, mutating furiously into still more impossibly beautiful forms, as if to say, Where have you been? How dare you leave us! Behold our power!

I had hoped ayahuasca would give me some consoling insight, but whatever was putting on this display for me brushed my pathetic human concerns aside. Your loves and fears are irrelevant here, I seemed to be told. Forget them! Look at this! Three-dimensional, four-dimensional, infinite-dimensional manifolds in paradisal hues.

Waves of vertigo washed over me. I was hurtling backwards through space with all these clattering, jabbering shards careening after me. To escape them, I opened my eyes again, but there was no escape, the sky was in turmoil too, convecting wildly, beaten to a froth by the throbbing rain-forest cacophony. I heard someone retching, far, far away, and I thought: At least I’m not sick.

My stomach convulsed and surged up my gullet. I grabbed my silver bucket just in time to catch a bolus of vomit, which flopped into the bucket like a jellyfish. I lurched to my feet, careened to an embankment near the circle, fell to my knees, and retched again as my head exploded into polychromatic streamers. All around me was a riot of color; the world dissolved into undifferentiated dayglo goo. A ten-foot pine tree at the bottom of the embankment quivered like a flame, fierce, fractal, exultant, discharging an unholy blue light. My head, too, sparked and crackled with electricity. Too much, I thought. I’m losing my mind. Too much. With a pang of guilt and horror I thought, What if I go mad? What will happen to my kids?

Some spider-like thing softly dropped onto my shoulder. Turning, expecting the worst, I saw only a human hand, a human face peering at me with concern. It was Tony. “Are you all right?” he asked. Yes, I muttered, and to my surprise I realized that I was all right. Some imperturbable part of me stood in the eye of the storm, calmly observing the chaos whirling around it.

Are you feeling the effects yet? Tony asked. I stared at him and emitted a grunt of incredulity. I’m completely blown away, I hissed. Aren’t you? Not yet, he said, shaking his head. I staggered back to my spot in the circle of stones. I felt purged, as Tony had promised earlier, but weak, jelly-kneed. I crawled into my sleeping bag and lay on my back.

With a crunch of gravel, Tony sat beside me. A few others were sitting or lying around the circle. The rest had wandered away, mostly to retch, as far as I could tell from the sound effects. Out in the darkness someone, a woman, was alternately laughing and moaning orgasmically: “Mmmm. Mmmm!” The music changed. The jungle sounds gave way to a flute ululating amidst the tintinnabulation of a million microscopic cymbals. The flute was mournful, plaintive, frail, lonely; it was humanity, lost, adrift, wandering through the infinite, oblivious, crystalline cosmos.

Tony shook a rattle and sang in an alien language. His voice was sweet, pure, poignant, incomprehensible. Sitting up, I tried to hum along with him, but the noises coming from me sound strangled, grotesque. I lay back and listened. Affection for Tony, for myself, for all of us welled up in me. We were all so tragic, comic, noble, brave, pathetic, blessed, doomed. Awash in these sentiments, again I closed my eyes. A dark, winged shape hovered briefly above me, blacking out the stars. A crow spirit? The angel of death? A cloud?

A voice, Tony, asked if I wanted more ayahuasca. Only an hour had passed! No thanks, I said. Tony approached others around the circle and asked the same question. Only Blaed, the youngest of us, accepted the supplement. My nausea had vanished, and with it my previous anxiety. In fact, I felt devoid of emotion, as if my frontal cortex were decoupled from my emotion-generating limbic system. Although the hallucinations kept deepening in intensity, I watched them now with an odd detachment, even making dry intellectual observations.

I reminded myself that this was all material, fodder for a book. How would I describe it? The visions were not organic, animalistic, jungly, as I expected. They were cartoonish, mechanistic, futuristic, science-fictionish. I recalled Terence McKenna’s descriptions of the entities he encountered on DMT trips: “merry elfin, self-transforming, machine creatures,” “friendly fractal entities,” “self-dribbling Faberge eggs on the rebound.”

But there were not alien creatures in the landscape before me; the whole landscape was alien. And there were not forms in space; form and space were inextricably tangled, and awash with unutterable, tip-of-the-tongue meanings. Another McKenna-ism came to mind, that through some strange synesthesia DMT renders visible syntax, the logic underpinning language and even thought.

The colors became ever-more-dazzling, the shapes ever-more-complex, until there were no shapes and colors any more. They yielded to something deeper and more fundamental than shape, color, syntax, thought: the metaphysical principles underlying all things, the machine code of reality. It occurred to me—or rather, to the cool, unemotional, pure intellect that I had become--that the particle physicists are right after all: God is a geometer, an infinitely intelligent, infinitely creative, utterly inhuman geometer.

The soundtrack shifted again, to a bass droning sporadically interrupted by blaring klaxons and what sound like large metal sheets being shaken and scratched. It was a demented dirge, a soundtrack for a psychotic disintegration, a descent into the underworld. It was annoying.

Desperate to get away, I crawled out of my sleeping bag and stood, wobbly-legged. Only two other people were still in the circle, encased in their sleeping bags; everyone else had scattered. I had a sudden urge to see the moonlit Pacific. I headed away from the circle and through the front gate of the ranch, and I soon spotted Tony, Kevin, and Blaed, standing beside an old weather-beaten barn overlooking the ocean. Michael stood slightly apart from the others gripping a blanket around his shoulders and occasionally retching. Tony asked how my night was going, and I tried as best as I could to describe my cartoonish, sci-fi, alien visions. Classic DMT hallucinations, Kevin said.

Blaed said the ayahuasca’s effects were interesting, but he had expected something more intense and long-lasting, more like LSD. Tony said Blaed should have had another supplement. Tony said he recently supervised an ayahuasca session with a Norwegian psychotherapist who couldn’t get enough of the stuff, even though it made him very sick. After vomiting for the umpteenth time, the therapist crawled over to Tony on his hands and knees and groaned, “More.” Everyone laughed at Tony’s story.

All at once I felt the same peculiar combination of weakness and surging energy that had signaled the onset of the ayahuasca. Dizzy, I drifted away from the group and stared at the ocean. The moon seemed small, impossibly distant. A thin stream of milky light poured down from it and vaporized as it struck the ocean, which was black and luminous, like molten lead, sheathed in a silvery miasma.

Something shifted, and the scene turned horrific. The moon was the sun, shrunken to a white dwarf, its life-sustaining heat and energy long since radiated away, barely illuminating the chill cinder of the earth. I was seeing the future, long after humanity, and all of life, has vanished from the earth. The flame of consciousness has flickered out in the eternally expanding cosmos, and it has reverted to dumb, blind, painless, meaningless matter, as it must.

Michael began retching again. Kevin said we should probably head back and see how the others are doing. Shuffling back toward the ranch along with my companions, I felt stunned, disoriented, isolated by my end-of-life epiphany. Several times I opened my mouth to tell the others about it, but the words didn’t come. Gradually, my comrades’ conversation dragged me back from the lifeless future to the present.

Blaed, the youngster among us, complained about Tony’s music selection, especially that Tibetan shit. Blaed’s uncle Kevin agreed that the Tibetan music was awful. I realized they meant the droning dirge that drove me away from the circle. I said nothing, worried that Tony’s feelings might be hurt, but he accepted the criticism with good humor and promised to rethink his selections. Blaed rattled off several groups whose music would be great for an ayahuasca session. None of the groups was familiar to me. I suggested that old psychedelic rock might be nice, like Iron Butterfly’s “Inna Gadda Da Vida.” My companions laughed, apparently thinking I was joking.

Did anyone see that meteor earlier tonight? Blaed asked. He’s never seen a meteor so big and so close; he actually saw burning chunks splitting off of it! Blaed and Kevin took turns pointing out different constellations in the sky. Someone asked why the Pleiades look so misty. It’s a huge cloud of gas, I said, still in the process of condensing into stars; astronomers call it a stellar nursery.

That set Tony off on a discussion of the ubiquity of birth metaphors in science and in the myths of indigenous people. Tony was intrigued by the theory of Stanislav Grof that the trauma of birth plays a crucial role in shaping our psyches. But Tony thought Grof tried too hard to link all transpersonal experiences to these perinatal experiences. No single theory, Tony said, can explain the immense variety of psychedelic visions.

We arrived back at the circle, around which sleeping bags sprawled like monstrous larvae. Exhausted, I climbed into my sleeping bag and dozed off. When my eyes opened the sky was brightening, the stars fading. I walked away from the circle to write down some notes. Michael, who had been too sick to speak a few hours ago, sat beside me. He was feeling much better. He had only recently become interested in psychedelics, he told me. His experiences helped him cherish his family, his wife and two-year-old daughter, and they reminded him that there’s more to life than the rat-race. His wife was a devout Christian and fairly conservative; she didn’t join him in taking psychedelics, but she understood why he did.

When we returned to the circle, everyone was awake, comparing notes on their evenings. Blaed asked whether anyone else heard or saw strange flashes, booms, and howling noises during the night, or was it just him? Others confirmed that they heard the same strange noises. Actually, said Linda, the explosions were real; someone at a nearby ranch was apparently setting off fireworks. As for the howling noises, she added, those were coyotes. If only it were always so easy to distinguish reality from illusion, I thought.

Nancy, the muscular firefighter, was beaming. She had had a cathartic trip, in which she relived lots of things from her childhood; the only bad part was that she threw up on herself. Brad said his experience was disappointing; he vomited early and often and never had any hallucinatory effects. You should have asked for a supplement, Tony chided him.

This was an unusually uneventful night, Tony commented. Usually at least one person becomes convinced that he’s going insane or dying. Tony had learned various tricks from shamans that can help people pass through these ordeals. He hums and lays his hands on the sufferer’s forehead or solar plexus. Sometimes he blows softly between the person’s shoulder blades or on the top of the head. Tony had no idea why these tricks work, but they do.

We walked back to the main house for a breakfast of bagels, scrambled eggs, and coffee. Tony, seated beside me, asked me how I felt. Surprisingly good, considering, I replied. That’s typical, Tony said. People often feel refreshed the morning after an ayahuasca session. It can be a wonderful time for writing, painting, composing music, doing anything creative. He hoped someday to set up a center where scientists, artists, businesspeople, and others could take ayahuasca for creative problem-solving. I tried to imagine corporate executives pondering internet marketing strategies as they spewed out dayglo vomit.

After breakfast, we headed back to the circle for a final ceremony. Each of us was supposed to untie the knot we made in Tony’s prayer rope the previous evening and say something. For the most part, everyone stuck to fairly generic expressions of thanks--to Allen and Deborah for letting us use their home for this ceremony, to Tony and Kevin for supplying the ayahuasca and guiding us, to the entire group for just being there, and to the ayahuasca plant spirits for transporting us into their realm.

The last person to speak was Deborah, who had seemed so melancholy the day before, and had been quiet all morning. She said a few words, haltingly, then broke down sobbing. Allen, her husband, took her in his arms and rocked her back and forth. Trying to lighten the mood, Kevin asked: If God takes LSD, does He see people? To my ears, the joke sounded more ominous than funny.

It was almost noon when I said goodbye to my companions. I drove a few miles down the road from Allen and Deborah’s ranch to a tiny inn, deep in a redwood forest, where I had reserved a room. Lying on the bed with a notebook in my lap, I tried to recollect as much as I could from the previous evening, and to make sense of it all. Considering how long it had been since I had slept, my mind felt strangely clear, almost too clear.

There was something both touching and absurd about the whole evening. We all went to great lengths to take this stuff that we knew would sicken us and might frighten us half to death. Why? Perhaps for the same reason we watch horror movies: We expose ourselves to this simulacrum of darkness to inoculate ourselves against the true darkness that will claim us all someday.

In retrospect, my ayahuasca visions seemed more like products of my own brain than transpersonal revelations. Ayahuasca showed me a universe of dazzling, alien pyrotechnics; as our group leader Kevin told me, those are characteristics of DMT, just as sensations of communion and compassion are characteristics of MDMA. Maybe the psychedelic skeptics are right: When we take a drug, we don’t discover reality, whatever that is; we just discover the effects of the drug.

The visual hallucinations reminded me of the neurophysiological theory of form constants, the distinctive geometrical patterns triggered by psychedelics. Each time a neuron discharged in my visual cortex last night, it triggered a cascade of neural firing around it according to the chemical rules dictated by DMT and other ingredients of ayahuasca. Subjectively, I perceived these effects as a wildly convecting cellular automaton—albeit one with infinite dimensions and hues. And perhaps because of some miscommunication between my brain’s hemispheres, I attributed the visual hallucinations to an alien intelligence, or what psychologist Michael Persinger would call a “sensed presence.”

As for the end-of-life vision I had while gazing out over the Pacific, well, that was just a waking version of nightmares I had had since childhood, when I first learned that at any moment missiles could fall from the sky and destroy everything. That was not to say my vision last night was wrong. The laws of probability dictate that now and then our dreams and nightmares come true.

I had hoped that ayahuasca would give me some sort of consoling insight, to help me deal with death, but what had I seen? A cold, inhuman intelligence underlying reality. A Demiurge without a heart. The inevitable end of the world, of life, of consciousness. Real comforting. Of course, all our Gods are just illusions, products of our innate compulsion to find order in the world, an anthropomorphic order. If we look hard enough, we see our own reflections everywhere.

Trying to sum things up I wrote: “So, what is the final lesson? Do I see only what I already believe? Is it too late to learn? Change? Do I want to learn and change? Need to?” I stared at the words, wracking my brain for some sort of epiphany, but nothing came. I felt more confused, more mystified, than ever. What is the point of all our mystical searching? Where does it get us? What truth does it give us? What consolation?

It was late afternoon when I pulled on shorts and jogging shoes and ran down the dirt road leading away from my inn. As I huffed and puffed my way up a hill lined with stoic redwoods, a station wagon pulled up next to me. At the wheel of the car was Deborah. The last time I saw her, just after the rope ceremony that morning, she had still been puffy-eyed, wracked by her secret grief. She seemed composed now, her aura of sadness dissipated. Beside her was a boy perhaps ten years old, who had her fair hair and skin and wide-set blue eyes. Her son, Deborah said, introducing us. She said she was glad to have met me, and I said likewise. Still catching my breath, I stood and watched as her car climbed slowly up the hill and vanished around a curve.

Further Reading:

"My Lunch with Psychedelic Chemist 'Sasha' Shulgin (RIP) and His Wonderful Wife"

Tripping in LSD’s Birthplace: A Story for ‘Bicycle Day’

Doubts about psychedelics from Albert Hofmann, LSD’s discoverer

DMT is in your head, but it may be too weird for the psychedelic renaissance

Was Psychedelic Guru Terence McKenna Goofing About 2012 Prophecy?