Medical Cannabis and Cannabinoids
Also known by these names
Cannabinoids derived from hemp generally have no intoxicating effects.
Laura Pole, RN, MSN, OCNS, BCCT Senior Researcher
Nancy Hepp, MS, BCCT Project Manager
Teresa Martin, BSc
Last updated August 24, 2021.
Medical cannabis is a plant product—either raw or dried—or an extract or preparation for medical use that is made from Cannabis sativa L., Cannabis indica or hybrid plant varieties. Cannabinoids are substances that are found naturally in cannabis. Examples include delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). All cannabinoids are psychoactive; however, THC is considered the only cannabinoid which causes intoxication.
Different varieties of cannabis can contain widely different levels of THC. Hemp has virtually no THC, and so hemp plant products and cannabinoids derived from hemp generally have no intoxicating effects.1
Medical cannabis and cannabinoids are used with success in patients experiencing nausea and vomiting and to stimulate appetite. Medical cannabis and cannabinoids also reduce pain, showing effects comparable to weak opioids.
Treating the Cancer
Working against cancer growth or spread, improving survival, or working with other treatments or therapies to improve their anticancer action
No evidence in humans or animals currently indicates that medical cannabis is a cure for cancer.
Due to the legal controversy surrounding medical cannabis, studies of its anticancer effects in humans are lacking, although animal studies are encouraging. However, no evidence in humans or animals currently indicates that medical cannabis is a cure for cancer. BCCT cautions against foregoing conventional treatment to take medical cannabis in hopes of curing cancer.
Lab and Animal Evidence
CBD and other cannabinoids have shown anti-tumor effects in exploratory lab and animal research:2
Managing Side Effects and Promoting Wellness
BCCT advisor, hospice and palliative care physician and author BJ Miller, MD, discusses the use of cannabis for pain control.
BCCT advisor Brian Bouch, MD, advocates for the use of CBD in cancer care.
Managing or relieving side effects or symptoms, reducing treatment toxicity, supporting quality of life or promoting general well-being
How It Works
How Do Cannabinoids Affect Our Bodies?
All cannabinoids, whether natural or synthesized, interact with the endocannabinoid system in the human body, mimicking the effects of our endogenous cannabinoids (endocannabinoids, substances naturally occuring in our bodies). Cannabinoids activate specific cannabinoid receptors, particularly CB1 found predominantly in the central nervous system and CB2 found predominantly in cells involved with immune function.7
Cannabinoids have been promoted to exert palliative effects in cancer patients:10
Evidence is not clear-cut. A 2018 review and meta-analysis found no significant differences between cannabinoids and placebo for improving caloric intake, appetite, nausea/vomiting, a decrease in pain greater than 30 percent, or sleep problems in cancer patients.11 In contrast, a separate review from the National Academies of Sciences, Engineering and Medicine reported these outcomes related to cancer:12
- Conclusive or substantial evidence that cannabis or cannabinoids are effective for treating pain in adults and chemotherapy-induced nausea and vomiting
- Moderate evidence for secondary sleep disturbances
- Limited, insufficient or absent evidence supporting improvement in appetite or anxiety
Finding Medical Cannabis
These medical societies maintain resources for patients and practitioners:
The United Patients Group (UPG) website includes information on the Medical Cannabis Industry’s “Trusted Seal of Approval” for products, organizations, and healthcare professionals. The site lists UPG Seal of Approval recipients.
As of 2018, 30 states and the District of Columbia have laws broadly legalizing cannabis in some form.19 Medical cannabis is moderately available in many locations in these states.
Choosing among Forms of Cannabis
To choose the formulation that is right for you, practitioners advise working with a healthcare provider experienced in prescribing and monitoring medical cannabis.28 Levels of active ingredients of natural products can vary widely between and even within products. See Quality and Sources of Herbs, Supplements and Other Natural Products.
Cardiovascular Health Effects
Smoking marijuana carries many of the same cardiovascular health hazards as smoking tobacco. While the level of evidence is modest, there’s enough data to advise caution in using marijuana for patients at highest risk of cardiovascular events, including those who present with a heart attack or new arrhythmia, or who have been hospitalized with heart failure.29
THC in marijuana can have these effects:30
- Stimulates the sympathetic nervous system ("fight or flight"), which increases heart rate, myocardial oxygen demand, blood pressure, and platelet activation
- Inhibits the parasympathetic nervous system ("rest and digest")
- Associated with endothelial dysfunction ( a type of non-obstructive coronary artery disease) and oxidative stress
Other Side Effects
According to CAM-Cancer, “A number of adverse events have been observed after the intake of medical cannabis and cannabinoids. Some may be welcome, such as mood enhancement or sedation.”31 Side effects include these:
Medical supervision and monitoring is advised when using cannabis for medical purposes. Cannabis can impair driving and other tasks requiring judgment and rapid response, so caution is warranted.
To review possible adverse events, side effects, contraindications and drug
interactions, see CAM-Cancer Summaries: Medical cannabis and cannabinoids: Is it safe?
A review including a pooled analysis of three case-control studies concluded that more than 10 years of marijuana use was associated with testicular germ cell tumor, but not with head and neck squamous cell carcinoma or oral cancer.35 Cancer-promoting activity has been found in breast, bronchial, hepatoma, and lung cell lines in some studies.36
Interactions with Other Therapies
CBD interacts with antiepileptic drugs, enhancing the serum levels of some and reducing the level of others.37
Dependence and Addiction
CBD shows no indications for addiction or dependence in humans.
Using cannabis can lead to substance use disorders such as physical and/or psychological dependence in some people:38
- Psychological dependence occurs when a person cannot willfully stop using the drug even though use interferes with many aspects of life.
- Physical dependence on cannabis can develop with sustained use.39 However, 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.40 Any withdrawal symptoms are typically mild and might include anxiety, insomnia, loss of appetite, migraine, irritability and restlessness.41
Integrative Programs, Protocols and Medical Systems
|For more information about programs and protocols, see our Integrative Programs and Protocols page.|
- Programs and protocols
BCCT staff December 28, 2017: From Donald Abrams’ article Integrating cannabis into clinical cancer care:
“One of the more distressing situations that oncologists increasingly face is trying to counsel the patient who has a curable diagnosis, but who seeks to forego conventional cancer treatment in favor of depending on cannabis oil to eradicate their malignancy because of the large number of online testimonials from people claiming such results. Given my long practice in San Francisco, I can assume that a large proportion of my patients have used cannabis during their journey. If cannabis cured cancer, I would have a lot more survivors in my practice today.”
Non-cancer Uses of Cannabis and Cannabinoids
In some states, certain qualifying medical conditions are recognized for permitted medical use of cannabis:46
Cannabinoids are also used to treat HIV-related peripheral neuropathy.47 BCCT has not reviewed the effectiveness of this therapy for non-cancer uses.
We are grateful to integrative oncologist and BCCT advisor Donald Abrams, MD, for his generous sharing of research articles and commentary.