CANNABINOIDS

Cannabinoids were one of the things that came up almost immediately after Stu was diagnosed. People talked about CBD, THC, cannabis oil, Sativex and RSO, often with enormous certainty about what they could do. As with everything else, I started reading. What made cannabinoids difficult to navigate was the mixture of science, early research, personal stories, legal issues and some very big claims online. We explored them ourselves, including through a legal prescription for Sativex, and later went further than that.

Five years later, cannabinoids are still being researched in glioblastoma. There is now a UK clinical trial specifically investigating Sativex alongside temozolomide in recurrent glioblastoma. But there is still a very important distinction between something being scientifically interesting and something being a proven treatment.

WHY WE LOOKED AT CANNABINOIDS

Cannabinoids are compounds that interact with the body's endocannabinoid system. Some occur naturally in the cannabis plant, including THC and CBD, while others can be produced synthetically. THC and CBD aren't the same thing. THC is psychoactive and can make someone feel high. CBD doesn't have the same intoxicating effect. Different cannabis-based medicines contain different cannabinoids, strengths and ratios, which is one reason why talking about “cannabis” as though it were one treatment isn't particularly helpful.

What interested me was the research suggesting that cannabinoid pathways might be relevant to glioblastoma. There had been laboratory research looking at effects on glioma cells, and researchers were investigating mechanisms including cell death, proliferation, invasion and interactions with conventional treatments.

That research has continued. A 2025 systematic review found substantial ongoing preclinical work involving cannabinoids and glioma, including combinations with temozolomide and radiotherapy. But it also highlighted the gap between laboratory research and clinical evidence in people. That gap matters. A substance doing something interesting to tumour cells in a laboratory does not automatically mean it will successfully treat a brain tumour in a person.

WHAT WE DID

We didn't use cannabinoids instead of Stu's conventional treatment. They were something we explored alongside it. Initially I wanted to find a legal, controlled way of doing that. We eventually obtained Sativex privately. Sativex, also known as nabiximols, is an oromucosal spray containing THC and CBD. It wasn't being prescribed to Stu as an established glioblastoma treatment. We were using it off-label because of the emerging research around cannabinoids and glioblastoma. It was expensive, particularly when we were already spending money on so many other things.

But at the time, if I found something that appeared biologically interesting, had some research behind it and could potentially be used alongside Stu's treatment, I wanted to investigate it. That was pretty much how my brain worked for those 10 months.

SATIVEX AND GLIOBLASTOMA

This is one area where something we were following in 2021 has moved forward. A small phase 1b clinical trial investigated nabiximols alongside temozolomide in people with recurrent glioblastoma. The study primarily looked at safety and feasibility. Nabiximols was generally tolerable with individualised dosing and researchers did not identify an apparent effect on the pharmacokinetics of temozolomide. There was also an interesting survival signal. In the randomised part of the study, 83% of participants receiving nabiximols were alive at one year compared with 44% receiving placebo. That sounds dramatic. But the numbers were tiny: only 12 people received nabiximols and nine received placebo, and two people in the placebo group died within the first 40 days. It therefore could not establish that Sativex improves survival. What it did do was provide enough reason to investigate the question properly in a larger randomised trial. 

THE ARISTOCRAT TRIAL

That larger study is called ARISTOCRAT.

ARISTOCRAT is a UK phase II, double-blind, randomised, placebo-controlled clinical trial investigating whether adding nabiximols, also known as Sativex, to temozolomide improves outcomes for people with recurrent glioblastoma. The trial is specifically for people with first recurrence of MGMT-promoter-methylated, IDH-wild-type glioblastoma who meet its other eligibility criteria. Participants receive temozolomide alongside either Sativex or a placebo. Researchers are looking primarily at overall survival, as well as progression-free survival, quality of life and side effects. 

As of October 2026, the University of Birmingham trial website still lists ARISTOCRAT as recruiting, although its anticipated recruitment end date was 30 September 2026. If you are reading this because you or someone you love is interested in the trial, check the current trial status and speak to your treating oncologist rather than relying on the status shown here. University of Birmingham. Results have not yet been published. That means we still don't know whether adding Sativex to temozolomide helps people with recurrent glioblastoma live longer. But I find it extraordinary that something we were trying to navigate ourselves in 2021 is now being investigated in a proper UK randomised clinical trial.

RSO AND WHAT HAPPENED TO US

We also explored something very different: Rick Simpson Oil, usually called RSO. RSO is a concentrated cannabis extract typically containing high levels of THC. Online, we encountered very specific protocols claiming that people with cancer should take particular quantities over a set period of time. We tried to follow one of those protocols. This is an area where I would do things differently now.

Unlike a prescribed medicine, an illicit or unregulated cannabis product may not contain what someone tells you it contains. We discovered that ourselves when oil we had obtained and believed to be high strength was tested and turned out to be nothing like the strength we thought we had bought. We lost money, but the bigger issue was that we had absolutely no reliable way of knowing what Stu was taking. I don't want to reproduce the dosing protocols or explain how to source RSO here. There is no established RSO protocol for treating glioblastoma and I don't want someone's treatment decision to be based on instructions they found on this website. That's very different from pretending we didn't use it. We did.

CANNABINOIDS ARE NOT ALL THE SAME

This is probably one of the most important things I've learned. CBD oil bought as a supplement, high-THC cannabis oil, RSO and a pharmaceutical product such as Sativex are not interchangeable. They can contain completely different amounts and ratios of cannabinoids, be manufactured to completely different standards and have different legal and medical status. That also means you cannot take evidence from a clinical trial involving one carefully controlled pharmaceutical cannabinoid product and assume it proves that another cannabis product will have the same effect. ARISTOCRAT is testing nabiximols. It is not testing RSO or an arbitrary CBD oil bought online.

MEDICAL CANNABIS IN THE UK

The legal position is also different from the way many of us understood it a few years ago. Cannabis-based medicines can legally be prescribed in the UK in certain circumstances. NHS access is very limited and the NHS currently says very few people in England are likely to receive an NHS prescription. Sativex itself is licensed in the UK for certain adults with muscle spasticity caused by multiple sclerosis, not as a treatment for glioblastoma. nhs.uk. That does not mean cannabis is generally legal, nor does it mean cannabis-based medicines are approved treatments for glioblastoma. Products bought online can also vary enormously in their contents and quality. The NHS warns that some products sold online may be illegal and potentially dangerous, and that their quality and contents may not be known. nhs.uk

INTERACTIONS AND SIDE EFFECTS

Cannabinoids are biologically active substances. That means they can have side effects and interact with medicines. Depending on the product and cannabinoids involved, possible side effects include dizziness, fatigue, nausea, diarrhoea, changes in mood or behaviour and psychoactive effects. CBD and THC can also affect how other medicines work. nhs.uk . For someone with a brain tumour, that matters particularly because they may already be taking chemotherapy, steroids, anti-seizure medication and other drugs. If I were doing this again, I would discuss any cannabinoid product with the medical team and give them the exact product and dose rather than just saying “CBD” or “cannabis oil”.

HINDSIGHT

WHAT WE KNOW NOW THAT WE WISH WE'D KNOWN THEN

Would I still investigate cannabinoids if Stu were diagnosed today? Yes. There is enough science here that I understand completely why we were interested, and the fact that nabiximols has progressed into a randomised UK glioblastoma trial reinforces that for me. But I would draw much harder lines around what the evidence does and doesn't tell us. I wouldn't treat laboratory research as evidence that something works in humans. I wouldn't assume evidence about one cannabinoid product applies to another. And I wouldn't follow an online RSO protocol as though it were an established cancer treatment.

Most importantly, I wouldn't put myself in the position of trying to source an unregulated high-THC product from people I didn't know and then somehow work out whether what we'd bought was even what they claimed it was. In 2021, I wasn't interested in waiting ten years for science to catch up while my husband had a cancer with a prognosis measured in months. I understand exactly why I made the decisions I made. Five years later, I can also see the difference between being willing to explore something uncertain and being able to recommend it to someone else. Those aren't the same thing.

CURRENT INFORMATION · 2026

CANNABINOIDS & GLIOBLASTOMA

Laboratory and preclinical research continues to investigate cannabinoids in glioblastoma, including possible effects on tumour-cell survival, signalling, the immune environment and responses to chemotherapy or radiotherapy. These findings are scientifically interesting, but cannabinoids have not been established as a treatment for glioblastoma in humans. A 2025 systematic review concluded that discrepancies between preclinical findings and clinical data mean rigorous clinical trials are still needed before cannabinoid-based treatments can reliably be incorporated into standard glioma care. 

NABIXIMOLS / SATIVEX

Early clinical research found that nabiximols could be given alongside temozolomide with acceptable tolerability and no apparent effect on temozolomide pharmacokinetics. The small randomised part of the study produced an interesting survival signal, but it was far too small to establish a survival benefit. 

ARISTOCRAT

ARISTOCRAT is a UK randomised phase II trial investigating nabiximols plus temozolomide versus temozolomide plus placebo in recurrent MGMT-methylated glioblastoma. The trial is designed to investigate overall survival as its primary outcome, alongside other outcomes including progression-free survival, quality of life and adverse events. University of Birmingham. Results have not yet been published.

RSO

There is no established clinical evidence showing that Rick Simpson Oil treats or cures glioblastoma, and there is no clinically validated RSO dosing protocol for glioblastoma. Evidence from research involving specific pharmaceutical cannabinoid formulations should not be used as evidence that RSO will have the same effect.

SAFETY

THC and CBD can cause side effects and interact with other medicines. Anyone considering cannabinoid products during cancer treatment should discuss the exact product with their medical team. nhs.uk

Medical disclaimer: This website shares our personal experience of glioblastoma and is not medical advice. Always discuss treatment decisions with your medical team.

FURTHER READING & RESEARCH

ARISTOCRAT TRIAL
The University of Birmingham's official ARISTOCRAT pages explain the trial, current status, eligibility and participating centres. Find the detailed patient information and eligibility criteria here. 

PHASE 1B NABIXIMOLS + TEMOZOLOMIDE STUDY
The small randomised clinical study that preceded ARISTOCRAT and investigated nabiximols alongside temozolomide in recurrent glioblastoma.

ARISTOCRAT TRIAL PROTOCOL
The peer-reviewed protocol describing the design and rationale for the larger randomised ARISTOCRAT trial.

2025 CANNABINOIDS & GLIOMA SYSTEMATIC REVIEW
A recent systematic review covering cannabinoid and glioma research published between 2022 and 2025, including mechanisms, combination approaches and the limitations of the current evidence.

NHS · MEDICAL CANNABIS
Current NHS information about cannabis-based medicines, prescriptions, online cannabis products, side effects and interactions.

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