Sandoz’s Withdrawal of Delysid was a decisive change in the material conditions under which LSD research and therapy could proceed. Delysid had circulated through a network of clinicians, treatment centers, and investigators, helping make experiments and therapeutic sessions possible. Its withdrawal belongs to a larger history in which research practices, clinical claims, and the availability of the drug could not be separated: the work depended not only on ideas about LSD, but also on access to the substance and on the human arrangements surrounding its use.

The Research Network Before Withdrawal

By the late 1950s, Al Hubbard was carrying Sandoz LSD among research groups and practitioners across North America. His travels connected work in Weyburn with meetings in Manhattan and sessions in Los Angeles; he also brought supplies and therapeutic advice to researchers. In Vancouver, he persuaded Hollywood Hospital to dedicate a wing to treating alcohol dependence with LSD, and he established other Canadian treatment facilities. Delysid therefore belonged to a practical network of supply and personal exchange, not merely to a laboratory program. Researchers and therapists relied on the movement of the drug alongside knowledge about how to conduct sessions.

The Saskatchewan work illustrates what this network made possible. Humphry Osmond and Abram Hoffer came to understand that the experience could be shaped by the room, the instructions, and the presence of an engaged therapist. The provincial government helped make LSD therapy a standard treatment option for alcohol dependence. When Toronto’s Addiction Research Foundation attempted a more tightly controlled replication, volunteers received the drug in neutral rooms, were left without therapeutic engagement, and were sometimes constrained or blindfolded. The results did not match the Saskatchewan trials, and some participants underwent terrifying experiences. The disagreement exposed a tension central to the drug’s clinical history: a supply of LSD could support treatment, but the treatment’s outcome could not be understood as the drug’s effect alone.

What the Withdrawal Changed

Withdrawal matters because Delysid had been a channel through which LSD reached investigators and practitioners. Hubbard’s journeys, in particular, show how a commercial supply could become part of a dispersed therapeutic infrastructure. He moved between centers, shared ampules, and trained people in his methods. In Menlo Park, Myron Stolaroff’s colleagues at Ampex began meeting to discuss LSD and human potential; Hubbard came to guide their sessions and train them to guide others. When Stolaroff and Willis Harman established the International Foundation for Advanced Study in 1961, the foundation secured LSD and mescaline through Hubbard. These examples reveal how research depended on personal intermediaries as well as formal institutions.

The withdrawal is consequently significant as a rupture in that arrangement, although the available account does not specify its exact timing, terms, or stated rationale. It should not be treated as the sole explanation for the retreat of psychedelic research: regulatory action, institutional conflict, and changing public attitudes also shaped the period. Nor does the evidence establish that every research group or therapist immediately lost access. What it does show is the vulnerability of a field whose work had relied on a manufacturer’s supply and on networks that carried the drug from one setting to another.

From Formal Research to Underground Practice

The end of an established supply route did not erase the knowledge developed by earlier clinicians and guides. The later underground therapists described in the book often traced their professional lineages to researchers and practitioners active when psychedelic work was legal, including Timothy Leary, Stanislav Grof, Al Hubbard, and Leo Zeff. Zeff helped establish practices such as strict confidentiality, a prohibition on sexual contact, and the expectation that guides should have personal experience with the medicines they administered. He also argued that a guide should allow a session to follow its own course and offer human warmth rather than retreat behind an analyst’s detached manner.

This transmission makes the withdrawal part of a broader transition, not a clean ending. Underground practice preserved and adapted methods formed in the earlier research era. Myron Stolaroff later argued that the renewed university research of the late 1990s had developed partly from anecdotal evidence gathered by underground therapists, as well as from the first wave of formal studies. Some underground guides were subsequently asked to help train guides for university trials, and Johns Hopkins researchers consulted underground practitioners about music in guided psilocybin sessions. The knowledge crossed the institutional boundary even when the work itself remained illegal.

Later Research and the Limits of the Legacy

The later revival of clinical research gave the earlier history renewed relevance without proving every claim made during the first wave. In 2016, studies at New York University and Johns Hopkins reported clinically significant reductions in anxiety and depression for about 80 percent of participating cancer patients, with benefits lasting at least six months. The trials were small, and the results required replication on a larger scale. A separate feasibility study at Imperial College London gave psilocybin to people with treatment-resistant depression; its early results were encouraging, but the study was small and lacked a control group.

The book places such findings beside a warning against treating psychedelics as universal remedies. Early studies can benefit from small, selected samples and unusually intensive therapeutic attention; initial enthusiasm and placebo effects may also inflate apparent promise. The evidence supports taking the results seriously as signals, not as settled proof of cure. Seen in this longer arc, Sandoz’s Withdrawal of Delysid marks a change in the conditions of research, while the persistence of therapeutic knowledge and the eventual return of clinical trials show that the field’s history was not simply a story of supply ending and inquiry stopping.