Medical Marijuana & Cancer: Can Cannabis Cure Cancer?

Written by Review Weed Cannabis & Health Enthusiast
Published: 2023-09-17
Medical marijuana and its potential for treating cancer

Table of Contents

Medical cannabis has long been studied to manage cancer symptoms and side effects of treatments like chemotherapy.

Research shows there is potential for marijuana in the fight against cancer. It can improve the quality of life in cancer patients by helping relieve symptoms like nausea, appetite loss, chronic pain, and a lack of sleep.

But whether it can cure cancer is an entirely different question. Animal and lab studies have shown cannabinoids have antitumour properties that can slow down growth and induce the death of cancer cells. These outcomes have not been studied greatly in human clinical trials.

In this article, we will look at the research trends of cancer & cannabis, along with how should a cancer patient use the plant to find the best comfort.

Cancer & cannabis: A scientific look

Over 40 years of research have looked at the mechanisms of how cannabinoids and cannabis compounds like terpenes affect the signs of cancer in the body.

We have summarised the most important findings below.

Antitumor ability of marijuana: Fighting cancer cells

Research conducted in laboratory settings (in vitro) and in living organisms (in vivo) has demonstrated that cannabinoids can tackle the significant signs of cancer development. These include uncontrolled cell growth, inflammation, resistance to cell death, and the ability of cancer cells to invade nearby tissues, form new blood vessels, and spread to other parts of the body (metastasis).

Cannabinoids can stimulate apoptosis, which is the natural programmed death of cells, including cancer cells. By inducing apoptosis in cancer cells, marijuana contributes to suppressing their growth.

A 2022 review study published in the Cancers Journal validated these results with a close look at research data. The US National Cancer Institute also provided an in-depth look into how THC and CBD produce their antitumor effects.

Battling different types of cancer

Lab experiments & tests have shown promising results in how cannabinoids produce their anticancer effects on various types of cancer. The same is stated in a 2020 review paper titled ‘Anti-Cancer Potential of Cannabinoids, Terpenes, and Flavonoids Present in Cannabis.’

Breast cancer

Studies have shown that certain cannabinoids, like THC and CBD, may exhibit anticancer effects against breast cancer cells. They have shown the ability to hinder cell proliferation, induce apoptosis (cell death), and suppress the migration and invasion of cancer cells. According to, cannabis has been reported to ease the side effects of traditional breast cancer treatments, such as chemotherapy-induced nausea and pain.

Lung cancer

Preclinical studies have suggested that cannabinoids could have antitumor effects in lung cancer. They have shown potential in reducing tumour growth and inhibiting the spread of cancer cells. Cannabis may also have bronchodilatory properties, which could help improve lung function and alleviate symptoms in lung cancer patients.

Colorectal cancer

Cannabinoids have shown promise in inhibiting the growth and proliferation of colorectal cancer cells. They have been found to induce apoptosis and impede the formation of blood vessels supporting tumour growth. Some studies have also suggested that cannabinoids may synergise when combined with traditional colorectal cancer treatments, enhancing their anticancer effects.

Prostate cancer

Research has indicated cannabinoids may have antiproliferative (suppressing growth) and apoptotic effects on prostate cancer cells. They have been found to inhibit cell growth, induce programmed cell death, and stop the spread.


Studies have shown that cannabinoids – when taken individually or together – can reduce tumour growth and cause apoptosis in melanoma cells. This is because melanoma cells have CB1 and CB2 receptors (present in the endocannabinoid system), and activating them with the molecules like CBD and THC can lead to decreased growth and metastasis.

Similar positive effects of cannabinoids are also seen in other cancer forms like brain cancer, leukaemia, glioma, ovarian cancer, and pancreatic cancer.

Easing symptoms: A boost in palliative care

Medical marijuana has shown definite promise in improving the quality of life of cancer patients.

Medical cannabis can help with pain, nausea, appetite, sleep, and mood.
Medical marijuana and cancer – a quick summary of main benefits.

Many patients globally use weed to sleep better, relieve their pain, and manage the symptoms of cancer and cancer treatments like chemotherapy.

This was put to the test by Thai researchers in 2021. The study looked at cancer patients who were given cannabis-based treatment from two hospitals – Roi-Et Regional Hospital and Sawang Dandin Crown Prince Hospital – and compared their quality of life with patients who got standard treatment. The results found that the cannabis-medicine group had far better quality-of-life scores when compared to the other patient group.

Here are four ways how the plant can assist in palliative care.

Nausea & vomiting

In the USA, two cannabinoid medicines – dronabinol and nabilone – are approved by the Food & Drug Administration to treat vomiting and nausea induced by chemo. They are given to patients who have not responded to standard treatments.

In Thailand, the Governmental Pharmaceutical Organisation (GPO) has also approved four classes of cannabis oil for patients battling cancer. These extracts are not meant to cure the cancer but ease the symptoms.


It is a well-known fact that marijuana makes you hungry. Although very few published studies look at cannabis & appetite loss in cancer patients, many patients swear by using weed to improve their appetite.

Sleep & pain

The link between medical cannabis & sleep is as old as time itself. Humans have used weed to sleep better for millennia, with numerous studies explaining how it works.

Similarly, pain is another reason why people take medicinal weed. Many studies have shown cannabinoids affect pain-signalling pathways in the body, leading to reduced pain. They are also excellent anti-inflammatories, which makes them valuable for pain relief. For example, nabaximols (brand name Sativex) is a class of medicine that help cancer patients with pain.

Cancer patients often suffer from poor sleep and increased pain. While cannabis cannot cure the condition, it can help relieve these symptoms.

Anxiety & stress

Marijuana can help people deal with cancer better. The plant has shown promise in reducing anxiety & stress, which can help patients relax and improve their overall perspective.

Please note that the effectiveness of medical cannabis depends on the dosage, the person's metabolism, genetic factors, conditions, and the type of product used.

Taking medicinal-grade weed for cancer: What to know

Marijuana is not an outright cure for cancer.

At Weed Review, we want to stress that if you plan to add medical cannabis to your cancer-treatment plan, please speak to a doctor first. There are plenty of legal, medical marijuana clinics & hospitals which specialise in recommending the right products & dosages for your needs.

There are three cannabis products that you may take to ease your symptoms:

  • Edibles & gummies: Cannabis-infused food items like gummies, candies, and brownies are common in dispensaries. These come in a standardised dosage and take between 45 minutes to 2 hours to produce their effects. The effects last for 4-6 hours, thus making it an ideal solution for long-lasting relief.
  • Tinctures & oils: CBD oil & THC oil extracts are also readily available. Place a few drops under the tongue, hold for 60 seconds, and swallow. The effects are felt within 15-30 minutes, and they last for 3-4 hours. Quality cannabidiol tinctures are more medicinal grade as they undergo strict quality measures. For best results, we recommend opting for a GPO-based formulation after talking to your doctor.
  • Flowers: Marijuana cultivars with varying terpenes and cannabinoid profiles are also available. Depending on how much CBD, THC, or terpenes they have, the effects will be different. You can either smoke them, vaporise them, or cook them in edibles. The doses may not be accurate.

Choose a high-quality product with third-party lab tests, good reviews, and a good brand reputation for best results.

Does smoking cannabis cause cancer?

It is not clear if smoking weed regularly causes lung cancer, just like tobacco. This is due to a lack of human studies.

However, there are four things to know:

  • Many people add tobacco to cannabis to make it burn better. This ‘indirect’ consumption of tobacco can contribute to the development of cancer.
  • Cannabis smoke also contains carcinogens – the same type of cancer-causing substances found in tobacco.
  • Cannabis smokers hold the smoke in their lungs for a long time when compared to regular cigarette smokers.
  • Cannabis smoke can contribute to respiratory problems and may increase the chances of catching lung infections.

These trends are likely to be seen in heavy, chronic cannabis smokers.

If you smoke weed regularly and are planning to take it for your cancer, please speak to your doctor for the best advice.

Side effects to consider

Taking cannabis has side effects; you can find the full list here.

The psychoactive substance in cannabis – THC – can cause many short-term effects like increased heart rate, dry mouth, nausea, headache, increased sensitivity to your surroundings, and an overactive mind. These tend to fade within 30-45 minutes of reaching the peak ‘high.’

The long-term, chronic use of cannabis can lead to an addiction/dependence on the substance. It can also cause breathing problems (if smoking), affect cognitive functioning, and possibly interfere with your daily life. These side effects are generally seen with THC.

CBD – the non-psychoactive chemical in marijuana – does not have these effects. It is considered to be much safer and is generally well-tolerated.

Another thing to note is the potential drug interaction with marijuana. Cannabinoids can interfere with the working of your medication by affecting the liver enzymes. This can change the concentration of the drug in your body, leading to adverse reactions. If you are taking drugs for chemotherapy or other anti-cancer medicines, please speak to your doctor before adding CBD or THC into this mix.

When you start using weed regularly to manage your cancer symptoms, you should keep a long-term picture in mind. Using CBD: THC in the right ratio can mitigate many of these side effects and even prevent dependency. That said, many patients use medicines for life – so medical cannabis can very well be added to that picture.


Marijuana has proven to be a valuable addition to the fight against cancer. In-lab and animal studies show that cannabinoids can induce apoptosis and inhibit cancer cell proliferation and metastasis in various cancer models.

What is needed now are clinical trials on humans. Researchers are looking at verifying these promising results in human models too.

In the meantime, we know that marijuana can help manage the symptoms of cancer & cancer-related treatments. For cancer patients, this means better sleep, less pain, better appetite, and a better quality of life. That said, these effects will differ from person to person and depend on the dosage, the type of product, and your individual genetics and biology.

For best results, speak to your doctor beforehand to see how medicinal marijuana can support your cancer recovery.