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.

How can cannabis and cannabinoids help you? What the research says

We summarize the clinical evidence for each medical benefit here. We begin with our assessment of the strength of evidence within each category, followed by a brief summary of individual studies or reviews of several studies. In assessing the strength of evidence, we consider the study design, number of participants, and the size of the treatment effect (how much outcomes changed with treatment).

To see more details, click the plus sign to the right of any section.

A brief summary of preclinical evidence is in Are you a health professional? ›

Improving treatment outcomes

Is cannabis or cannabinoids linked to improved survival? Is it linked to less cancer growth or metastasis? Does it enhance the anticancer action of other treatments or therapies? We present the evidence.

Cancer as a whole

Weak evidenceone or more case studies, supported by animal evidence OR small treatment effects of limited clinical significance OR studies with no controls OR weak trends of effects (this is the CancerChoices definition; other researchers and studies may define this differently) of anticancer effects and reduced tumors

Brain cancer

Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of tumor response among people with recurrent glioblastoma multiforme treated with cannabis

Lung cancer

No evidence of an effectoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments. on time to tumor progression or survival after first-line monotherapy pembrolizumab among people with metastatic non-small cell lung cancer treated with cannabis

Optimizing your body terrain

Does cannabis or cannabinoids promote an environment within your body that is less supportive of cancer development, growth, or spread? We present the evidence.

See Optimizing Your Body Terrain ›

Find medical professionals who specialize in managing body terrain factors: Finding Integrative Oncologists and Other Practitioners ›

We also recommend that you share with your doctor the information here about how cannabis or cannabinoids might affect these terrain factors if you have any imbalances.

High blood sugar and insulin resistance

Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of lower blood sugar levels among people with type 2 diabetes treated with THCV

Your microbiome

Preliminary evidence of beneficial changes in the relative numbers of microbial species in the tongues of people without cancer with chronic inhalation-based exposure to cannabis

Managing side effects and promoting wellness

Is cannabis or cannabinoids linked to fewer or less severe side effects or symptoms? Is it linked to less toxicity from cancer treatment? Does it support your quality of life or promote general well-being? We present the evidence.

Side effects as a whole

No evidence of an effectoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments. on total symptom distress scores among people with advanced cancer treated with titrated CBD oil in a study

Anxiety

Insufficient evidencepreclinical evidence only OR clinical studies with such poor or unclear methodology that no conclusion can be drawn OR conflicting findings across clinical studies with no preponderance of evidence in one direction; conflicting evidence occurs when studies find conflicting effects (positive effect vs no effect or negative effect) with the same treatment and the same general study population (same cancer type, for example) (this is the CancerChoices definition; other researchers and studies may define this differently) of fewer anxiety symptoms among people with cancer using cannabis or cannabinoids

Changes in appetite

No evidence of an effect on appetite among people with cancer treated with cannabis or cannabinoids in several analyses of studies

Gastrointestinal effects

Modest evidencesignificant effects in at least three small but well-designed randomized controlled trials (RCTs), or one or more well-designed, mid-sized clinical studies of reasonably good quality (RCTs or observational studies), or several small studies aggregated into a meta-analysis (this is the CancerChoices definition; other researchers and studies may define this differently) of less chemotherapy-induced nausea and vomiting among people using cannabis or cannabinoids

Modest evidence of less vomiting among people treated with cannabinoids compared to neuroleptics (antipsychotic medication)

Modest evidence of comparable effects on nausea and vomiting among people treated with cannabinoids compared to prochlorperazine

Neurological symptoms

Modest evidence of lower neuropathic pain scores among people with pain treated with THC/CBD or THC alone

Weak evidenceone or more case studies, supported by animal evidence OR small treatment effects of limited clinical significance OR studies with no controls OR weak trends of effects (this is the CancerChoices definition; other researchers and studies may define this differently) of relief from unmanageable (refractory) seizures in one person with recurrent glioma treated with CBD

Pain

Modest evidence of less cancer-related pain among people treated with either cannabis or some cannabinoids

Insufficient (conflicting) evidencepreclinical evidence only OR clinical studies with such poor or unclear methodology that no conclusion can be drawn OR conflicting findings across clinical studies with no preponderance of evidence in one direction; conflicting evidence occurs when studies find conflicting effects (positive effect vs no effect or negative effect) with the same treatment and the same general study population (same cancer type, for example) (this is the CancerChoices definition; other researchers and studies may define this differently) of an effect on pain among people treated with opioids when adding cannabinoids in combined analyses of studies

Quality of life and function

Modest evidence of a very small improvement in physical functioning but no evidence of an effect on quality of life among people with chronic pain or cancer treated with cannabis or cannabinoids

Sleep disruption

Insufficient evidence of better sleep quality among people with cancer or chronic pain treated with oral cannabis or cannabinoids

Symptoms not specific to cancer

Modest evidence of fewer anxiety symptoms among people with non-cancer medical conditions  treated with pharmaceutical THC either with or without CBD

Good evidence of lower pain scores among people with pain treated with cannabis or cannabinoids

Modest evidence of less opioid use among people receiving opioid treatment for chronic pain also treated with medical cannabis for at least 30 days

Reducing cancer risk

Is cannabis or cannabinoids linked to lower risks of developing cancer or of recurrence? We present the evidence.

Head, neck, and oral cancer

No evidence of an effectoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments. on cancer recurrence of oropharynx squamous cell carcinoma among people using cannabis in a preliminary study

No evidence of an effect on risk of head and neck squamous cell carcinoma among people using cannabis

Keep reading about cannabis and cannabinoids

Authors

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

Reviewer

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: November 2, 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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