An invitation that was never sent
Some of Alexander Shulgin’s texts are as valuable for the chemistry they contain as they are for the portrait they paint of an era. Chapter 13 of TIHKAL, titled “Flashbacks,” is one of them: it begins with a bureaucratic anecdote and ends up becoming one of the cleanest refutations of the anti-drug folklore that circulated—and still circulates—about LSD.
The episode takes place in mid-December 1991. The DEA, the US drug enforcement agency, organized a two-day conference in San Francisco dedicated to LSD. About two hundred people attended, including police commanders from the Netherlands, Great Britain, and Australia. The official host was Robert C. Bonner, then the agency’s acting administrator. The choice of city was no coincidence: many agents assumed that most of the world’s LSD was manufactured in the Bay Area.
Shulgin, who was an obvious reference on the history of the substance due to his career as a chemist, heard rumors that he would likely be invited to present on the origin and early uses of the drug. He received a printed invitation, but he sensed the problem himself: PIHKAL had just been published, and someone within the police apparatus could read that book not as the objective archive of information it was, but as an apology for psychedelics. To avoid compromising the DEA contact who had proposed his name, he gave notice that, for his part, he did not yet consider any official invitation finalized.
Shortly after, the polite and diplomatic call arrived: the invitation was canceled. In fact, as he was told, the original was never actually sent. And the reason was not PIHKAL—“nobody seemed to worry about that book,” he was assured—but the fear of one of the divisions that Shulgin would drag Bonner into an “embarrassing” public debate.
Shulgin himself laughed at the scene: a gray-haired chemist with an academic air putting one of the country’s most powerful police officials on the spot. Embarrassing for whom? If the hierarchy feared their boss would be exposed in an argument with him, they had a poor opinion of their boss. In retrospect, he recognized that staying home was fortunate: had he attended, he would have either spoken—and it would have been more than disturbing—or he would have remained silent, ashamed of himself.
The “jihad” against a molecule
What Shulgin reconstructs from that conference, partly by hearsay, is the moral climate rather than the technical content. He describes an atmosphere of a crusade: LSD presented as absolute evil, something that had to be eradicated from the face of the Earth at any cost. He compares it, with bitter irony, to witch hunts or inquisitorial condemnations: enemies defined in advance for whom no punishment seemed excessive.
A good part of the hostility was aimed at people. The manufacturers were criminals; “sociopathic therapists” went into the woods to access their hidden stockpiles of precursors and continued to defend—it was said—the myth that the substance had some therapeutic value, a pretext for their own addiction. But another part of the anger was directed at the molecule itself, and that is where the argument that gives the chapter its title appears.
The most striking claim handled in that room was, in essence, this: a single exposure to LSD could leave “persistent” molecules hidden in the frontal lobe, lurking for up to twenty years, and suddenly reappear, triggering a flashback capable of unleashing psychosis. As proof, San Francisco itself was pointed to: after the Summer of Love in the late sixties and its massive consumption of psychedelics, there were the streets full of homeless people with mental disorders. The cause, according to this theory, was those latent molecules finally reaching the frontal lobes.
What pharmacology says
The core of the chapter is Shulgin’s response to that narrative, and it is devastatingly simple. LSD, once in the body, produces its effects and is then eliminated—it and its metabolites—rapidly. Shulgin places its elimination half-life in the blood at less than three hours: after that time, only half of what was there remains; after one day, more than 99% has been excreted. A huge dose taken on a Monday would not leave even 1% on Tuesday, and no known analytical technique would detect it on Wednesday.
Hence his conclusion: if a single molecule—or even a billion molecules—were enough to induce psychosis, we would be looking at a drug of unprecedented potency, never before observed. It is not science; it is fantasy—something that only exists, he says, “in the imagination of law enforcement and in the publications of those who make a living fostering fear of drugs.”
And yet—and this is the elegant twist of the text—flashbacks do exist. What happens is that they are not what that theory claimed. They do not belong exclusively to LSD, nor do they have anything to do with psychosis. They are, quite simply, memories.
The flashback as memory, not latent chemistry
Shulgin illustrates this with a scene of his own. While playing the viola at a musical gathering, during a medley by Duke Ellington titled something like “To Duke, with Love,” he suddenly remembered an Ellington concert he had attended in Boston in the winter of 1941 or 1942. He had walked through the snow without shaking it from his hair; once seated in the audience, the snow began to melt and the water to drip down his neck, without him daring to move so as not to wet those around him. The embarrassment of that moment returned intact decades later, triggered by the music.
That is the mechanism. A smell, a word, a familiar sound can trigger a cascade of memories intense enough to relive a past scene. And a strong psychedelic experience, precisely because it focuses attention in an extraordinary way on certain sensory stimuli, leaves especially vivid anchors: re-encountering that stimulus later can bring back the experience. The event remembered may be objectively trivial. The explanation, Shulgin concludes, lies in the functioning of memory and the mind—not in LSD—and certainly not in any molecule lost in the frontal lobes, because there would be nothing left to look for there.
Critical reading
Shulgin’s text is, above all, a polemical piece from 1997, written to dismantle the anti-drug propaganda of his time, and it should be read with that in mind. Some useful clarifications:
- The pharmacological argument holds up. The idea of LSD molecules “sleeping” for years in the brain has no basis; the substance is eliminated in hours. Shulgin is right about that, and subsequent literature supports it.
- “Flashback” also has a narrower clinical meaning. Psychiatry recognizes Hallucinogen Persisting Perception Disorder (HPPD), in which some people experience recurrent visual disturbances after consumption. It is rare and its mechanism is not well understood, but it is not equivalent to the “evoked memory” Shulgin speaks of, nor to the fable of latent psychosis. It is best not to confuse the three concepts.
- The social critique he makes—attributing poverty and mental disorders on the streets to LSD—remains relevant: it is an example of correlation turned into causation to support a policy. But it should not be read in reverse as proof of the harmlessness of psychedelics.
- Harm reduction. Just because a myth is false does not make the substance harmless. Intense experiences with psychedelics can destabilize people with a predisposition to certain disorders, and context, dose, and mental state matter. This article is educational and historical; it is not a consumption guide.
As an editorial note: this chapter was part of a Spanish translation project of PIHKAL and TIHKAL promoted by the so-called Shulgin Project in Spanish. We include the content for its educational and historical interest; the reference works are the original PIHKAL and TIHKAL by Alexander and Ann Shulgin.
