Psilocybin for Cancer

Psilocybin for Cancer: Safety & Side Effects

This page covers safety information for Psilocybin. See our complete Psilocybin therapy guide →

Author

Nancy Hepp, MS

past Lead Researcher

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Ms. Hepp is a researcher and communicator who has been writing and editing educational content on varied health topics for more than 20 years. She serves as lead researcher and writer for CancerChoices and also served as the first program manager. Her graduate work in research and cognitive psychology, her master’s degree in instructional design, and her certificate in web design have all guided her in writing and presenting information for a wide variety of audiences and uses. Nancy’s service as faculty development coordinator in the Department of Family Medicine at Wright State University also provided experience in medical research, plus insights into medical education and medical care from the professional’s perspective.

Nancy Hepp, MS past Lead Researcher

Clinical reviewers

Laura Pole, MSN, RN, OCNS

Senior Clinical Consultant

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Laura Pole is senior clinical consultant for CancerChoices. Laura is an oncology clinical nurse specialist who has been providing integrative oncology clinical care, navigation, consultation, and education services for over 40 years. She is the co-creator and co-coordinator of the Integrative Oncology Navigation Training at Smith Center for Healing and the Arts in Washington, DC. Laura also manages the “Media Watch Cancer News That You Can Use” listserv for Smith Center/Commonweal. In her role as a palliative care educator and consultant, Laura has served as statewide Respecting Choices Faculty for the Virginia POST (Physician Orders for Scope of Treatment) Collaborative as well as provided statewide professional education on palliative and end-of-life care for the Virginia Association for Hospices and Palliative Care.

For CancerChoices, Laura curates content and research, networks with clinical and organizational partners, brings awareness and education of integrative oncology at professional and patient conferences and programs, and translates research into information relevant to the patient experience as well as clinical practice.

Laura sees her work with CancerChoices as a perfect alignment of all her passions, knowledge and skills in integrative oncology care. She is honored to serve you.

Laura Pole, MSN, RN, OCNS Senior Clinical Consultant

Jennifer Bires, LICSW, OSW-C

CancerChoices Advisor

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Jennifer Bires, LICSW, OSW-C was recently the executive director of the Smith Center for Healing and the Arts in Washington, DC. She is a rising star in the psycho-oncology field with almost a decade of experience as an oncology social worker, most recently at George Washington University in DC where she helped create the cancer support program. During her tenure at GWU she created a number of deep and impactful programs for families, young adults, and patients and helped to ensure program success by defining and tracking outcomes. Jennifer received the 2017 Oncology Social Worker of The Year Award from the Association of Oncology Social Workers.

Jennifer Bires, LICSW, OSW-C CancerChoices Advisor

Side effects and adverse reactions

Supervised use of psilocybin has shown few serious adverse events.¹Lewis BR, Garland EL et al. HOPE: a pilot study of psilocybin enhanced group psychotherapy in patients with cancer. Journal of Pain and Symptom Management. 2023 Sep;66(3):258-269; Grob CS, Danforth AL et al. Pilot study of psilocybin treatment for anxiety in patients with advanced-stage cancer. Archives of General Psychiatry. 2011 Jan;68(1):71-8. A study of effects from more than 1000 administrations in 30 studies found only nine serious adverse events.²Romeo B, Kervadec E et al. Safety and risk assessment of psychedelic psychotherapy: s meta-analysis and systematic review. Psychiatry Research. 2024 May;335:115880. A large observational study found no associations between lifetime use of psychedelics and lifetime diagnosis of either any cancer or hematologic cancer specifically.³Barnett BS, Ziegler K, Doblin R, Carlo AD. Is psychedelic use associated with cancer?: Interrogating a half-century-old claim using contemporary population-level data. Journal of Psychopharmacology. 2022 Oct;36(10):1118-1128. 

Side effects reported in studies include “an increased risk for elevated heart rate, systolic and diastolic blood pressure for all dose range categories, as well as an increased risk of nausea during the acute phase. Other common side effects included headaches, anxiety, and decreased concentration or appetite.”⁴Romeo B, Kervadec E et al. Safety and risk assessment of psychedelic psychotherapy: s meta-analysis and systematic review. Psychiatry Research. 2024 May;335:115880. 

Some studies not specific to cancer have found impaired memory, executive function, and/or attention after use of psilocybin.⁵Basedow LA, Majić T et al. Cognitive functioning associated with acute and subacute effects of classic psychedelics and MDMA—a systematic review and meta-analysis. Scientific Reports. 2024 Jun 26;14(1):14782; Gouzoulis-Mayfrank E, Schreckenberger M et al. Neurometabolic effects of psilocybin, 3,4-methylenedioxyethylamphetamine (MDE) and d-methamphetamine in healthy volunteers. A double-blind, placebo-controlled PET study with [18F]FDG. Neuropsychopharmacology. 1999 Jun;20(6):565-81. .

Some species of psilocybin mushrooms are mildly toxic and can cause gastrointestinal distress, and in rare cases serious side effects like liver or renal failure. This underscores the importance of utilizing psilocybin in a controlled setting where the practitioners have sourced psilocybin mushrooms with a good toxicity profile. Additionally, psilocybin products sold on the unregulated market (like edibles, chocolates) can be contaminated with unknown toxic substances.⁶Lowe H, Toyang N et al. The therapeutic potential of psilocybin. Molecules. 2021 May 15;26(10):2948. 

Psychological side effects are also possible. “In patients with mental or psychiatric disorders, suicidal ideation and auto-mutilation are possible risks of magic mushroom ingestion and, though rare, have been documented in the literature. Another risk is the possibility of exacerbating psychotic symptoms.” It is important for individuals with psychiatric conditions to speak with their healthcare team to assess the risks of a psilocybin session.⁷Lowe H, Toyang N et al. The therapeutic potential of psilocybin. Molecules. 2021 May 15;26(10):2948. 

Psilocybin use in the context of medical/psychiatric support and therapy is advised. Some people using psilocybin have very negative experiences, even becoming physically aggressive or violent or needing medical help.⁸Carbonaro TM, Bradstreet MP et al. Survey study of challenging experiences after ingesting psilocybin mushrooms: Acute and enduring positive and negative consequences. Journal of Psychopharmacology. 2016 Dec;30(12):1268-1278. One review concluded that adverse effects of medical psilocybin are manageable when administered according to risk management approaches, but it also has an abuse potential appropriate for scheduling under the US Controlled Substances Act.⁹Johnson MW, Griffiths RR, Hendricks PS, Henningfield JE. The abuse potential of medical psilocybin according to the 8 factors of the Controlled Substances Act. Neuropharmacology. 2018 Nov;142:143-166.

Contraindications

Schizophrenia, psychosis, borderline personality disorder, or bipolar disorder are contraindicated for psilocybin use. Pregnant or breastfeeding women should avoid psilocybin. Cardiovascular disorders could be contraindicated, and should be discussed with your doctor before pursuing a psilocybin session.¹⁰Lowe H, Toyang N et al. The therapeutic potential of psilocybin. Molecules. 2021 May 15;26(10):2948.

Drug interactions 

There are known drug interactions with this therapy, one of which is antidepressants and antipsychotics.

Interactions with medications and other interventions are complex. Always consult with a healthcare professional before adding any new therapy to your regimen. To learn more about interactions visit one of the trusted resources below: 

• About Herbs ›
• EfficaSafe ›

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