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Cannabis derivatives, CBD and brain tumour treatment

Is CBD oil good for a brain tumour? There’s now conclusive evidence for the use of cannabis-based products for managing the side-effects of brain tumours and brain cancer.

CBD and brain tumour treatment -  a drop of CBD oil drips from a dropper with canabis leaves in the background

Short summary

Cannabis derivatives that don’t contain THC are legal in the UK for use in the treatment of brain tumours.

Current research aims to discover whether cannabis derivatives might be able to help treat glioblastoma tumours. And, there is evidence to show that products like CBD oils are useful in managing the side-effects of brain tumours and their treatments, such as pain or nausea from chemotherapy.

On this page, we’ll look at cannabis derivatives like CBD and brain tumour treatment. We’ll answer:

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Cannabis, cannabinoids and cannabis derivatives

Cannabis is the dried preparation, or resinous extract, of the flowers or leaves of the cannabis plant, a member of the hemp family.

The parts of cannabis that are considered important for medical reasons are called cannabinoids. This is the name for the complex chemicals found in cannabis that are responsible for the effect cannabis has on the body. Two cannabinoids are of particular interest:

  • THC – delta-9 tetrahydrocannabinol (responsible for the psycho-active and addictive effects of cannabis)
  • CBD – cannabidiol

Cannabis derivatives is a general term for all products that are produced using different parts of the cannabis plant, including:

  • cannabis-based medicines that certain healthcare professionals can prescribe (for example, Sativex and Nabilone)
  • cannabis products that don’t contain THC, which can be sold legally in the UK as food supplements (for example CBD oil or hemp oil)
  • cannabis products that do contain THC, which are currently illegal in the UK (for example, street cannabis or cannabis oil).

It’s important that you understand the difference between cannabis products that contain CBD and cannabis products that don’t contain THC, as they can have different effects and are legally treated differently.

Cannabis derivatives in bottles on cloth surface, examining the effect of cannabis derivatives like CBD in brain tumour treatment

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Our community share their experiences with cannabis-based products

I am having chemotherapy and using CBD oil to help with the side-effects of that.

I used CBD oil to relax and try to reduce my anxiety levels.

I hoped CBD oil would reduce the size of my tumour, however it did grow. I use CBD oil to help with pain, and it makes me calmer and more relaxed.

I have never used cannabis products because my doctor wasn’t sure how it would interact with my other medications.

“I did not use cannabis medicines or products because I didn’t think they would improve or enhance the medication I was receiving.

I believe it can help with nausea, but talk to your doctor first because cannabis can interact with other medications.

These experiences from members of the brain tumour community are not intended as medical advice. Everyone is different and we encourage you to make decisions about using cannabis-products following discussion with your medical team.

Join the conversation in our Online Support Communities for more tips about coping with a brain tumour diagnosis from people who truly understand what you’re going through. 

Cannabis is an illegal drug in many countries, including the UK, where it is classified as a class B drug. This means it is illegal to posses, supply or produce cannabis in the UK. 

Cannabis-based products containing THC (for example, cannabis oil or medical cannabis) are also illegal in the UK, unless you have a valid prescription. 

Possession of a class B drug is punishable in the UK with up to 5 years in prison, an unlimited fine or both. Supply and production of a class B drug is punishable with up to 14 years in prison, an unlimited fine or both.

CBD and hemp oils

Cannabis-based products that don’t contain THC (for example, hemp oil or CBD oil) are currently legal in the UK – as long as it has been produced from an EU-approved strain of hemp and as long as it is marketed as a food supplement without any medicinal claims. You can buy these products in many high street health food shops. 

Buying cannabis-based products that aren’t from an EU-approved strain of hemp often means you cannot be sure the product is legal in the UK.

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CBD oil being dripped onto a spoon over a brown glass bottle - cannabis derivatives can be used in the treatment of brain tumours and their side effects

What is the evidence for cannabis-based products like CBD oil in the treatment of brain tumours?

Cannabis derivatives in treating brain tumours

Currently, the evidence that cannabis-based products can treat brain tumours or brain cancer is limited.

Preliminary studies from the lab suggest that cannabinoid chemicals THC and CBD can stop glioblastoma (GBM) cells from growing, causing them to die and disrupting the blood supply to the tumour cells.

In 2021, an early-stage trial led by Professor Susan Short suggested that adding a specific blend of these chemicals – in the form of a drug called Sativex – to chemotherapy could potentially help treat recurrent GBMs more effectively.

Cannabis derivatives in treating side-effects

Is CBD oil good for brain tumour treatment? There’s now conclusive evidence for the use of cannabis and its products, such as cannabis oil and CBD oil, for other therapeutic purposes in people with a brain tumour or cancer, i.e. for pain relief and treating chemotherapy-induced nausea and vomiting.

As such, the cannabis-based drug, Nabilone, has a medical licence and can be legally prescribed for chemotherapy-induced nausea and vomiting.

For more information, see the government’s review.

Cannabis medicines have been used to help with nausea, however these are different to the products that have been tested for use to treat cancers.

Professor Susan Short, Consultant in Clinical Oncology

If you have a question you can’t find an answer to on this page, please contact our Support and Information Line by ringing 0808 800 0004, emailing us at support@thebraintumourcharity.org or starting a live chat. The Support and Information Line is open Monday to Friday, between 9.00am and 5.00pm.

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Is it safe to use cannabis-based products like CBD oil during brain tumour treatment?

Any supplements, alternative or complementary treatments that you or your loved one wish to use could interact with other medications, such as anti-epileptic medicines, steroids or chemotherapy. You should always discuss this with your medical team before deciding to use cannabis-based products like CBD oil alongside brain tumour treatment.

It is important to be aware that you cannot be sure of the concentrations and ratios of THC and CBD in grown or street cannabis, and therefore cannot guarantee how safe it is. The same is true of other cannabis-products that aren’t prescribed by your healthcare team or produced from an EU-approved strain of hemp.

Susan Short, Consultant in Clinical Oncology, speaking about cannabis as an alternative medication for brain tumours and brain cancer.

How safe a cannabis product is will depend on the product itself and the other medications you are taking. You should speak to your medical team for advice before starting cannabis products.

Professor Susan Short, Consultant in Clinical Oncology

Side effects of using cannabis-based medications

Like all medications, cannabis-based medicines have side-effects. These will differ depending on the product you’re using, as well as your individual circumstances.

Your consultant or medical team will be able to talk to you about possible side-effects. They can also help you manage any side-effects you’re experiencing.

The side-effects may vary depending on the product. The common side-effects of Sativex (a cannabis-based medicine) are sickness, tiredness, dizziness and headaches.

Professor Susan Short, Consultant in Clinical Oncology

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cannabis derivatives being dripped into a bottle on a green background

How can I get cannabis-based products?

Cannabis-based medicines

Only specialist doctors who are listed in the General Medical Council’s (GMC) specialist register will be able to prescribe cannabis-based products. They will only be prescribed when the specialist considers that the patient will benefit and has a clinical need that cannot be met by licensed products.

  • Medicinal cannabis, therefore, will only be prescribed on a case-by-case basis
  • Patients will NOT be able to get cannabis-based products from their GP
  • If you feel you might benefit from these products, speak to your consultant or healthcare team
  • Administration by smoking remains prohibited.

If you’d like to know more, you could read our blog post on cannabis-based medicinal products. Or, read our information about accessing unlicensed drugs

Hemp and CBD oils

CBD and hemp oils do not contain THC and can be purchased in many high street health food shops.

Cannabis-based medicines are only available through a medical prescription. Cannabis-based products are available without a prescription but many of these are of unknown composition and are not equivalent to medicinal products.

Professor Susan Short, Consultant in Clinical Oncology

Speaking to your medical team about cannabis

We recognise this can be a difficult conversation to start with your, or your loved one’s, medical team. If you are interested in understanding if cannabis-based medications may be suitable for you or your loved one, or if you are considering a non-prescription cannabis product like CBD oil for brain tumour treatment, we recommend you speak with your medical team about this decision.

Cannabis-based medications (medical cannabis) are only likely to be prescribed to a small number of people with brain cancer or a brain tumour, and only for specific reasons

Here are some tips to help you have this conversation:

  • Explain why you are interested in cannabis-based medicines or products, and what you are hoping it could do for you or your loved one.
  • Let your medical team know you want them to be involved in decisions about using cannabis-based medicines or products.
  • Ask about research or clinical evidence for or against using cannabis-based medicines or products, and how this relates to your individual circumstances.

Remember, a medical professional’s concern is your health or the health of your loved one. This means they are likely to be open to discussing any medicines or complementary therapies that may be suitable.

Perhaps your medical team will say they don’t recommend any cannabis-based medicines or products for you. You can ask them why. There are often clinical and evidence-based reasons why cannabis-based medicines and products would not be suitable for you or your loved one. For example, because of interactions with other medications.

You may find the UK Medical Cannabis Clinicians Society’s (UKMCCS) guide to medical cannabis helpful when talking to your medical team. It includes information about access, legality, safety and side-effects of medical cannabis.

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