There's now conclusive evidence for the use of cannabis-based products for therapeutic purposes.
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.
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. You can use the ‘topics’ function within our Facebook support groups to read existing conversations about cannabis-based medicines and products, or start the conversation yourself by posting in the group.
Are cannabis-based products legal in the UK?
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.
What is the evidence for cannabis-based products in the treatment of brain tumours?
Treating brain tumours
Currently, the evidence that cannabis-based products can treat brain tumours themselves 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.
And, earlier this year, 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.
There's now conclusive evidence for the use of cannabis and its products, such as cannabis oil and CBD oil, for other therapeutic purposes, i.e. 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.
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Is it safe to use cannabis-based products?
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.
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.
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.
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 as well as how to 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.
How can I get cannabis-based products?
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 when the patient has an unmet special clinical need that cannot be met by licensed products.
- Medicinal cannabis, therefore, will 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.
(For more information, see our blog on cannabis-based medicinal products.)
Apart from the special circumstances described above, and the prescribing of Nabilone for chemotherapy-induced nausea and vomiting, it might be possible for Sativex to be accessed via off-label prescribing.
Off-label prescribing is where your doctor can prescribe a drug licenced for another condition, if they feel it would benefit you and there is no other licensed treatment or all licensed treatments have failed. Sativex is licensed for the treatment of spasticity (tightening of the muscles) in multiple sclerosis.
However, many doctors may be reluctant to prescribe off-label as the responsibility for the prescribing and any adverse effects, lies with them. Also the professional codes, ethics and prescribing policies of their hospital trust may prevent it. You can always speak to your doctor about this.
CBD and hemp 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.
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, 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, 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.