Learn what the evidence shows about treating cancer with Rick Simpson Oil (RSO), an oil made from the flowers of the cannabis (marijuana) plant. May be worth further exploring cannabinoids as potential cancer treatment, say researchers It may be worth exploring further the use of cannabidiol (‘CBD’) oil as a potential lung cancer treatment, suggest doctors in BMJ Case Reports after dealing with a daily user whose lung tumour shrank without the aid of conventional treatment. The body’s own endocannabinoids are […]
Rick Simpson Oil (RSO) for Cancer: Does It Work?
Rick Simpson Oil (RSO), an oil made from the flowers of the cannabis (marijuana) plant, gets attention online from people who claim it treats cancer. There’s no solid evidence for it. But some early research suggests that some chemicals in marijuana have future potential as a cancer treatment.
Cannabis oil comes in many types and formulations. These include cannabidiol (CBD) oil, which is often part of medical marijuana.
Unlike many other cannabis oils, Rick Simpson Oil is high in tetrahydrocannabinol (THC), which is the main psychoactive chemical in marijuana. THC is the chemical in marijuana that provides the “high.”
Online reports say Simpson is a Canadian engineer and cannabis activist. After a bad fall, he found that marijuana helped lessen his dizziness and other symptoms. Later, when he developed basal cell skin cancers on his arm, Simpson used cannabis oil as a treatment. As the reports go, his skin cancers went away.
What Is Rick Simpson Oil?
RSO is an oil made by washing cannabis buds with a solvent, such as pure light naphtha, and then boiling off the solvent leaving behind the oil.
RSO is not a branded product. That means there’s no one “Rick Simpson Oil” for sale. On his website, Simpson explains how to make his namesake oil. But he does not sell a version of the oil for profit.
Because RSO contains high levels of THC, it’s illegal to buy in many places. But in states that have legalized marijuana — either for personal use or for medical use — you can find RSO at cannabis dispensaries.
Can RSO Treat Cancer?
Cannabis oils that contain THC may help control nausea and vomiting for people who are going through chemotherapy. There’s also evidence that they can treat pain and improve appetite.
But research has not shown that RSO or other forms of cannabis oil can treat cancer. Some very early studies on using THC to treat cancer have been encouraging, though.
In animals and in the lab, studies have found that THC and other cannabis chemicals can stop the growth of tumors. These lab studies have looked at cells related to lung, skin, breast, prostate, and other cancers. They’ve found that cannabis can in some cases stop the cancer cells from spreading.
Other research on THC and other cannabis compounds shows that they may kill off cancer cells while sparing healthy cells.
Cannabis is generally safe. Common side effects include dizziness or memory problems.
Other Medical Uses of Cannabis
Many U.S. states and the District of Columbia have legalized marijuana for medical use. There’s evidence that it can treat pain, nausea, and other symptoms.
When it comes to cannabis oil, there are also medical benefits. Research has shown that some CBD oils, including those that contain THC, can help control certain types of seizures among people with epilepsy. The FDA has approved some drugs that contain CBD for seizure treatment.
Karger Open Access: “The Trouble With CBD Oil.”
Iranian Journal of Psychiatry: “Chemistry, Metabolism, and Toxicology of Cannabis: Clinical Implications.”
Leafly.com: “Who is Rick Simpson and what is Rick Simpson Oil (RSO)?”
Cannabinoids: “Cannabis Oil: chemical evaluation of an upcoming cannabis-based medicine.”
Clinical pharmacology and therapeutics: “Cannabis in Cancer Care.”
Journal of the American Medical Association: “Medical Marijuana for Treatment of Chronic Pain and Other Medical and Psychiatric Problems: A Clinical Review.”
Annals of Clinical and Translational Neurology: “A prospective open‐label trial of a CBD/THC cannabis oil in dravet syndrome.”
FDA: “FDA Approves First Drug Comprised of an Active Ingredient Derived from Marijuana to Treat Rare, Severe Forms of Epilepsy.”
PhoenixTears.ca: “Producing the Oil.”
Current Oncology: “Integrating cannabis into clinical cancer care.”
Pharmacotherapy: “The pharmacologic and clinical effects of medical cannabis.”
Harvard Health Publishing: “Cannabidiol (CBD) — what we know and what we don’t.”
Daily use of cannabidiol (‘CBD’) oil may be linked to lung cancer regression
It may be worth exploring further the use of cannabidiol (‘CBD’) oil as a potential lung cancer treatment, suggest doctors in BMJ Case Reports after dealing with a daily user whose lung tumour shrank without the aid of conventional treatment.
The body’s own endocannabinoids are involved in various processes, including nerve function, emotion, energy metabolism, pain and inflammation, sleep and immune function.
Chemically similar to these endocannabinoids, cannabinoids can interact with signalling pathways in cells, including cancer cells. They have been studied for use as a primary cancer treatment, but the results have been inconsistent.
Lung cancer remains the second most common cancer in the UK. Despite treatment advances, survival rates remain low at around 15% five years after diagnosis. And average survival without treatment is around 7 months.
The report authors describe the case of a woman in her 80s, diagnosed with non-small cell lung cancer. She also had mild chronic obstructive pulmonary disease (COPD), osteoarthritis, and high blood pressure, for which she was taking various drugs.
She was a smoker, getting through around a pack plus of cigarettes every week (68 packs/year).
Her tumour was 41 mm in size at diagnosis, with no evidence of local or further spread, so was suitable for conventional treatment of surgery, chemotherapy, and radiotherapy. But the woman refused treatment, so was placed under ‘watch and wait’ monitoring, which included regular CT scans every 3-6 months.
These showed that the tumour was progressively shrinking, reducing in size from 41 mm in June 2018 to 10 mm by February 2021, equal to an overall 76% reduction in maximum diameter, averaging 2.4% a month, say the report authors.
When contacted in 2019 to discuss her progress, the woman revealed that she had been taking CBD oil as an alternative self-treatment for her lung cancer since August 2018, shortly after her original diagnosis.
She had done so on the advice of a relative, after witnessing her husband struggle with the side effects of radiotherapy. She said she consistently took 0.5 ml of the oil, usually three times a day, but sometimes twice.
The supplier had advised that the main active ingredients were Δ9-tetrahydrocannabinol (THC) at 19.5%, cannabidiol at around 20%, and tetrahydrocannabinolic acid (THCA) at around 24%.
The supplier also advised that hot food or drinks should be avoided when taking the oil as she might otherwise feel stoned. The woman said she had reduced appetite since taking the oil but had no other obvious ‘side effects’. There were no other changes to her prescribed meds, diet, or lifestyle. And she continued to smoke throughout.
This is just one case report, with only one other similar case reported, caution the authors. And it’s not clear which of the CBD oil ingredients might have been helpful.
“We are unable to confirm the full ingredients of the CBD oil that the patient was taking or to provide information on which of the ingredient(s) may be contributing to the observed tumour regression,” they point out.
And they emphasise: “Although there appears to be a relationship between the intake of CBD oil and the observed tumour regression, we are unable to conclusively confirm that the tumour regression is due to the patient taking CBD oil.”
Cannabis has a long ‘medicinal’ history in modern medicine, having been first introduced in 1842 for its analgesic, sedative, anti-inflammatory, antispasmodic and anticonvulsant effects. And it is widely believed that cannabinoids can help people with chronic pain, anxiety and sleep disorders; cannabinoids are also used in palliative care, the authors add.
“More research is needed to identify the actual mechanism of action, administration pathways, safe dosages, its effects on different types of cancer and any potential adverse side effects when using cannabinoids,” they conclude.
Notes for editors
Please note: out of respect for patient confidentiality we don’t have the names or contact details of the cases reported in this journal.
Funding: None declared
Link to Academy of Medical Sciences labelling system
Externally peer reviewed? Yes
Evidence type: Single case report