Medical cannabis and cannabinoids in raw or dried flowers, oils, capsules, powders, edibles, and topicals may reduce pain, and some evidence shows benefit with nausea, vomiting, and sleep, but little evidence of improving treatment outcomes.

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This section does not replicate the other information on this topic but provides additional details or context most relevant to professionals.

Clinical practice guidelines

2023 guidelines provide these recommendations:

1.1 Health systems and clinicians, in partnership, should provide adults with cancer unbiased, evidence-based cannabis and/or cannabinoid educational resources to facilitate clinical communication, informed decision making, and systematized approaches to care.

1.2 Given the high prevalence of cannabis and/or cannabinoid use among adults with cancer, clinicians should routinely and nonjudgmentally inquire about cannabis use (or consideration of use) and either guide care or direct adults with cancer to appropriate resources.

Clinicians should remain sensitive to cannabis regulations’ disproportionate impacts on marginalized communities and work to omit cannabis-related and other biases (eg, racial, ethnic, and socioeconomic) from clinical discussions about cannabis and/or cannabinoids. 

1.3 When adults with cancer use cannabis and/or cannabinoids outside of evidence-based indications or clinician recommendations, clinicians should explore goals, educate, and seek to minimize harm.

2.1 Clinicians should recommend against use of cannabis and/or cannabinoids to augment cancer-directed treatment unless in the context of a clinical trial (weak recommendation).

2.2 Clinicians should recommend against use of cannabis and/or cannabinoids in place of cancer-directed treatment (strong recommendation).

3.1 Adults with cancer who receive moderately or highly emetogenic antineoplastic agents with guideline-concordant antiemetic prophylaxis and experience refractory nausea or vomiting may augment their antiemetic regimen with dronabinol, nabilone, or a quality-controlled oral 1:1 THC:CBD extract (weak recommendation).

3.2 Outside of a clinical trial, clinicians should not recommend that adults with cancer use 300 mg or more per day of oral CBD to manage symptom burden due to lack of proven efficacy and risk for reversible liver enzyme abnormalities (weak recommendation).

3.3 Evidence remains insufficient to recommend for or against cannabis and/or cannabinoids in managing cancer treatment-related toxicities or symptoms (including cancer pain), aside from clinical settings addressed in recommendations 3.1 and 3.2 or within the context of a clinical trial.

This guideline describes use of the cannabinoids dronabinol and nabilone for nausea and vomiting.

More on safety

Cannabis-derived therapies may cause adverse effects on the central nervous system including acute or prolonged psychotic states, distress, anxiety, sedation and more. Cannabis may not be recommended for use in individuals with some mental health conditions, and may also interact with prescription drugs and alcohol. Caution and medical supervision are advised.1Horn JR, Hansten PD. Drug interactions with marijuana. Pharmacy Times. December 9, 2014. Viewed January 5, 2023; International Programme on Chemical Safety. Cannabis sativa L. October 1989. Viewed October 9, 2021; American Cancer Society. Marijuana and Cancer. March 16, 2017. Viewed October 9, 2021; Kramer JL. Medical marijuana for cancer. CA: A Cancer Journal for Clinicians. 2015 Mar;65(2):109-22. Even so, the adverse effects of cannabinoids may compare favorably to those of other pain-management and cancer therapies.2Guzmán M. Cannabinoids: potential anticancer agents. Nature Reviews. Cancer. 2003 Oct;3(10):745-55. Some components of cannabis, such as CBD, provide therapeutic effects without any intoxicating effects.

Because THC is stored in fat and leaches out of the body fat to maintain a slowly diminishing blood level, users typically do not get an abrupt withdrawal reaction from sudden cessation of cannabis.3Abrams D. Email correspondence: Cannabis Abrams review. March 24, 2018. Any withdrawal symptoms are typically mild and might include anxiety, insomnia, loss of appetite, migraine, irritability and restlessness.4Crippa JA, Hallak JE et al. Cannabidiol for the treatment of cannabis withdrawal syndrome: a case report. Journal of Clinical Pharmacy and Therapeutics. 2013 Apr;38(2):162-4.

Cancer-promoting activity has been seen in breast, bronchial, hepatoma, and lung cell lines in preclinical studies.5Cridge BJ, Rosengren RJ. Critical appraisal of the potential use of cannabinoids in cancer management. Cancer Management and Research. 2013 Aug 30;5:304.

Safety and precautions: preclinical evidence

Cannabinoids promote progression of HPV-positive head and neck squamous cell carcinoma through p38 MAPK pathway activation in preclinical studies.6Liu C, Sadat SH et al. Cannabinoids promote progression of HPV-positive head and neck squamous cell carcinoma via p38 MAPK activation. Clinical Cancer Research. 2020 Jun 1;26(11):2693-2703. Cannabis has shown cancer-promoting activity in breast, bronchial, hepatoma, and lung cell lines in preclinical studies.7Cridge BJ, Rosengren RJ. Critical appraisal of the potential use of cannabinoids in cancer management. Cancer Management and Research. 2013 Aug 30;5:304.

Modes of action: activating cannabinoid receptors

All cannabinoids, whether natural or synthesized, interact with the endocannabinoid system (ECS) in the human body. Cannabinoids found in cannabis act on the ECS by mimicking the effects of our endogenous cannabinoids (endocannabinoids). Cannabinoids activate specific cannabinoid receptors, particularly CB1 found predominantly in the central nervous system and CB2 found predominantly in cells involved with immune function.8Abrams DI, Guzman M. Cannabis in cancer care. Clinical Pharmacology and Therapeutics. 2015 Jun;97(6):575-86.

Preclinical evidence of benefit

Notable preclinical evidence is listed here; clinical evidence is in How can cannabis and cannabinoids help you? What the research says ›

Improving treatment outcomes

  • “Cannabinoids possess anticancer potencies against glioma cells, however this effect varies with the combinations and dosages used” is the conclusion of a 2021 systematic review of preclinical evidence.9Kyriakou I, Yarandi N, Polycarpou E. Efficacy of cannabinoids against glioblastoma multiforme: a systematic review. Phytomedicine. 2021 Jul 15;88:153533.
  • Inhaled CBD not only limited tumor growth but also altered the dynamics of the tumor microenvironment in mice with glioblastoma10Khodadadi H, Salles ÉL et al. Inhalant cannabidiol inhibits glioblastoma progression through regulation of tumor microenvironment. Cannabis and Cannabinoid Research. 2021 Dec 16.
  • Slower progression of many types of cancer including glioblastoma, breast, lung, prostate and colon cancer in preclinical studies11McAllister SD, Soroceanu L, Desprez PY. The antitumor activity of plant-derived non-psychoactive cannabinoids. Journal of Neuroimmune Pharmacology. 2015 Jun;10(2):255-67.
  • Less angiogenesis, cell migration, and metastasis in preclinical studies12Bifulco M, Laezza C, Gazzerro P, Pentimalli F. Endocannabinoids as emerging suppressors of angiogenesis and tumor invasion (review). Oncology Reports. 2007 Apr;17(4):813-6.

Optimizing your body terrain

  • Hormone imbalance: inhibited progesterone activity, which creates precursors for sex steroid and glucocorticoid synthesis, with crude marijuana extracts from Delta(9)-tetrahydrocannabinolic acid (THCA)- and cannabidiolic acid (CBDA)-strains in preclinical trials13Watanabe K, Motoya E et al. Marijuana extracts possess the effects like the endocrine disrupting chemicals. Toxicology. 2005 Jan 31;206(3):471-8. 
  • Inflammation: anti-inflammatory action with CBD in preclinical studies14Nichols JM, Kaplan BLF. Immune responses regulated by cannabidiol. Cannabis and Cannabinoid Research. 2020 Feb 27;5(1):12-31; Pellati F, Borgonetti V et al. Cannabis sativa L. and nonpsychoactive cannabinoids: their chemistry and role against oxidative stress, inflammation, and cancer. Biomed Research International. 2018 Dec 4;2018:1691428.
  • Cannabis suppresses the immune response in preclinical trials15Nagarkatti P, Pandey R, Rieder SA, Hegde VL, Nagarkatti M. Cannabinoids as novel anti-inflammatory drugs. Future Medicinal Chemistry. 2009 Oct;1(7):1333-49.
  • Oxidation: both anti-oxidative and pro-oxidative actions with CBD in preclinical studies16Nichols JM, Kaplan BLF. Immune responses regulated by cannabidiol. Cannabis and Cannabinoid Research. 2020 Feb 27;5(1):12-31.

Helpful links for professionals

KNOW Oncology ›
A subscription is required; access is free of charge for members of the Society for Integrative Oncology.

Miller NS, Oberbarnscheidt T, Gold MS. Marijuana addictive disorders and DSM-5 substance-related disorders. Journal of Addiction Research & Therapy. 2017 Jan; S11:013.

Shannon S, Opila-Lehman J. Cannabidiol oil for decreasing addictive use of marijuana: a case report. Integrative Medicine (Encinitas, California). 2015 Dec;14(6):31-5.

Keep reading about cannabis and cannabinoids


Nancy Hepp, MS

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 Lead Researcher

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


Teresa Martin

Integrative patient advocate
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Teresa Martin, founder of Options Patient Advocacy, is an integrative patient advocate that helps patients find specialists and integrative healthcare professionals close to where they live. Scientifically educated, and passionate about patient-centered care, Teresa’s focus areas include integrative oncology, chronic lymphocytic leukemia, and condition-specific applications of medical cannabis.

Teresa Martin Integrative patient advocate

Last update: May 10, 2024

Last full literature review: October 2021

We are grateful to integrative oncologist and CancerChoices advisor Donald Abrams, MD, for his generous sharing of research articles and commentary.

CancerChoices provides information about integrative in cancer care, a patient-centered approach combining the best of conventional care, self care and evidence-informed complementary care in an integrated plan cancer care. We review complementaryin cancer care, complementary care involves the use of therapies intended to enhance or add to standard conventional treatments; examples include supplements, mind-body approaches such as yoga or psychosocial therapy, and acupuncture therapies and self-care lifestyle actions and behaviors that may impact cancer outcomes; examples include eating health-promoting foods, limiting alcohol, increasing physical activity, and managing stress practices to help patients and professionals explore and integrate the best combination of conventionalthe cancer care offered by conventionally trained physicians and most hospitals; examples are chemotherapy, surgery, and radiotherapy and complementary therapies and practices for each person.

Our staff have no financial conflicts of interest to declare. We receive no funds from any manufacturers or retailers gaining financial profit by promoting or discouraging therapies mentioned on this site.

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