One of the things we discovered fairly quickly after Stu was diagnosed was that there was a whole world of existing medications being investigated for possible uses in cancer that had absolutely nothing to do with what those drugs had originally been developed for. These are usually referred to as repurposed medications or repurposed drugs, and once we knew they existed, they became another part of the enormous amount of research we were doing alongside Stu's conventional treatment.

Some of the medications we came across will be familiar because they're prescribed every day for completely different conditions. Metformin is normally used for diabetes, atorvastatin for cholesterol, mebendazole for parasitic infections and doxycycline is an antibiotic. The theory behind repurposing is essentially that an existing drug may affect a biological process that is also relevant to cancer, even though cancer wasn't what the drug was originally designed to treat.

That doesn't mean that because a drug has an interesting mechanism, works in a laboratory or has shown promise in early research, it will necessarily improve outcomes for people with glioblastoma. That's an important distinction and one I understand much better now than I did when we were desperately reading everything we could find in 2021.

WHAT ARE REPURPOSED MEDICATIONS?

Drug repurposing isn't some weird alternative medicine concept. It is a legitimate area of medical research that looks at whether medicines already approved or used for one condition could potentially be useful for another.

There are obvious attractions to doing this. Existing medicines often already have years of safety information behind them, their side effects and interactions are better understood than those of completely new compounds and, in some cases, they are inexpensive and widely available.
But there's a really important gap between a drug already being approved for one condition and that drug being proven to treat another one.

This is where I think it can become incredibly confusing for patients and caregivers, particularly when you're researching something like glioblastoma and constantly finding laboratory studies, case reports, small trials and biological theories that sound incredibly promising. We were trying to understand all of this while simultaneously dealing with appointments, scans, treatment, work, family and the small matter of trying to keep Stu alive. It was a lot.

OUR EXPERIENCE

We first started properly exploring repurposed medications through Care Oncology, where Stu was prescribed metformin, atorvastatin, mebendazole and doxycycline alongside his conventional treatment.

From there, the subject became part of much wider conversations with the people we had brought into Stu's team. We discussed different drugs and combinations with Dr Michael Castro, Dr Etienne Callebout and other people we were working with, alongside Stu's NHS oncology care.
This wasn't a case of finding a list on the internet and ordering everything on it. There were medications we researched that we decided not to pursue, medications that weren't appropriate for Stu and things we discussed with doctors where the answer was simply no.

There were also practical questions about who would prescribe something, whether it could be obtained in the UK, what it might interact with and whether there was enough evidence to justify adding yet another thing to an already complicated treatment regime.

That was something I hadn't really appreciated at the beginning. You can find an exciting paper about a drug in about thirty seconds. Working out whether that paper has any meaningful relevance to the actual human being sitting next to you is considerably harder.

THE METRO MAP

Jane McLelland's book How to Starve Cancer had a big influence on the way I began thinking about all of this. Her Metro Map concept looks at the different metabolic pathways cancer cells can use and considers ways of targeting multiple pathways rather than thinking about cancer as one single process with one single target.

That led me down an enormous rabbit hole of research into metabolism, signalling pathways, supplements and repurposed drugs, and eventually I built my own spreadsheet pulling together information from Stu's CeGaT and Alacris reports, conversations with Dr Castro, Care Oncology, Dr Callebout, Patrice Surley and the research I was reading myself.

At the time I desperately wanted to find the right combination. I think that's understandable when somebody you love has been given a diagnosis like glioblastoma. You want there to be something you've missed, some combination nobody has thought of yet, some bloody lever you can pull that changes what happens next.

Looking back, I think about that slightly differently now. I'm still glad we explored it and I don't regret trying to understand Stu's tumour in as much detail as we possibly could, but having a biological rationale for combining different things is not the same as having clinical evidence that the combination will make somebody live longer.

WHY WE WERE CAREFUL

One of the dangers of the phrase repurposed medication is that it can make these drugs sound relatively harmless because they're already widely prescribed. They're still medicines.
They have side effects, contraindications and interactions, and those things become even more important when somebody is also having chemotherapy, radiotherapy, taking steroids, anti-seizure medication, supplements or other drugs.

That was why we tried to make sure the different people involved in Stu's care knew what he was taking. It wasn't always a particularly easy system to navigate because we had conventional oncology, private specialists and people working in integrative medicine all looking at slightly different pieces of the picture, but I didn't want us adding things without understanding how they fitted with everything else. I would be even more careful about that now. The fact that you can find research suggesting a drug might affect a particular cancer pathway doesn't tell you whether it's appropriate for a particular person, at a particular dose, alongside everything else they're taking.

We also used online interaction checkers as another layer of information. At the time, one of the most useful was the Cancer Drug Interactions checker developed by the University of Liverpool and Radboud UMC, which was specifically designed to look at interactions involving cancer treatments. Unfortunately, that resource is no longer actively maintained and its data was last updated in 2022, so I wouldn't rely on it as a current source now.

There are still online tools that can be useful for identifying things to ask about. The Drugs.com Interaction Checker allows you to check multiple medicines and supplements, while Memorial Sloan Kettering's About Herbs database is particularly useful for looking at herbs and supplements alongside cancer treatment. I would use tools like these as a way of spotting potential interactions and generating questions, rather than taking the absence of a listed interaction as proof that a combination is safe. Your oncologist, doctor or pharmacist still needs to know what you're taking.

WHAT DOES THE EVIDENCE LOOK LIKE NOW?

There is still significant scientific interest in repurposing existing drugs for cancer, including glioblastoma, but the evidence varies enormously depending on the individual drug.

Some drugs have compelling laboratory or animal data but very little useful evidence in people. Others have reached early clinical trials. Some have observational studies suggesting a possible benefit, only for other studies to produce less convincing results.

Metformin is a good example of why this is complicated. A 2025 systematic review and meta-analysis looking at metformin alongside temozolomide in high-grade glioma found an association with improved overall survival, although it did not find a significant improvement in progression-free survival. A much larger observational study published in 2026, looking at older people with glioblastoma, did not find that metformin use was associated with reduced mortality. 

Mebendazole is another drug that has attracted considerable interest because of its effects in preclinical brain tumour research. A 2026 systematic review found strong preclinical rationale and reported that early human studies suggested it was generally tolerable, but concluded that the clinical evidence available so far has not demonstrated meaningful efficacy in people with brain tumours. I don't think those mixed results mean researching repurposed medicines is pointless. To me, they show why it's important to distinguish between interesting, promising and proven, because those words are absolutely not interchangeable.

WHAT ABOUT THE NHS?

When we were researching repurposed medicines, NHS England had a national Medicines Repurposing Programme, which had been established to identify and support opportunities for existing medicines to be used for new purposes.

That programme was suspended in April 2025. NHS England said that, as the programme developed, fewer opportunities needed the kind of national support it had originally been designed to provide and relatively few medicines had sufficiently strong evidence to support changes to their licences. 
That doesn't mean research into repurposing medicines has stopped, or that existing drugs aren't still being investigated for new uses. It means that this particular NHS England programme is no longer operating in the way it was when I originally wrote this page.

2026 UPDATE

One of the biggest differences between researching this now and doing it in 2021 is the sheer amount of information that can be interrogated much more quickly. I spent hundreds of hours reading papers, trying to understand molecular pathways, cross-referencing Stu's reports and building spreadsheets to keep track of what we were finding. I would absolutely use AI to help with some of that now. I'd use it to explain terminology in a paper I didn't understand, compare findings across Stu's molecular reports, identify where two reports appeared to be saying different things, organise research by drug or pathway and help me formulate questions to take back to the people treating him.

What I wouldn't do is ask AI what drugs somebody with glioblastoma should take and then treat the answer as a treatment plan. The same applies to finding a study online. Research can give you something worth investigating and it can give you much better questions, but it can't tell you that a particular drug is safe or appropriate for the person sitting in front of you.
If anything, having better tools makes that distinction even more important because it is now incredibly easy to produce a very convincing-looking explanation for why a particular combination of drugs should work. Biology has an irritating habit of being considerably more complicated than that.

HINDSIGHT

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

I don't regret exploring repurposed medications. Given what we knew about glioblastoma and the options available to Stu, I would investigate them again. What I would change is how quickly we built the wider team around us and how much of the research burden I tried to carry myself. At the beginning we didn't know that people like Dr Castro, Dr Callebout or Patrice existed. We didn't know about molecular profiling, integrative oncology, Care Oncology or drug repurposing. We didn't even know what questions we were supposed to be asking, and by the time we discovered one thing it usually led to another five things we apparently needed to understand.

I also wouldn't look at the Metro Map now and think there must be a perfect combination somewhere if only I could research hard enough to find it. That is an enormous weight to put on yourself as a caregiver and it gives you a sense of control that, with hindsight, isn't entirely real. There are things we tried that may have helped Stu and things that may have made absolutely no difference. We will never know. I don't need to retrospectively turn any of them into the reason he lived for as long as he did in order to believe that investigating his options was worthwhile. What mattered was that we kept asking questions, kept looking beyond the first answer we were given and tried to make informed decisions with the information we had at the time.

If I were doing this again now, I'd still research repurposed medications, but I'd build the right people around us earlier, use AI to take some of the enormous research and organisational burden off me and keep asking the same question whenever something sounded exciting: What is the actual evidence for this in people with glioblastoma? That question would have saved me a lot of rabbit holes.

CURRENT INFORMATION

The evidence around individual repurposed medicines is continually changing, so I wouldn't rely on a static list of drugs on this site as a guide to what somebody should take. If you're interested in a particular repurposed medication, I'd look at the current evidence for that specific drug, whether there are clinical trials involving it and discuss it with the medical professionals involved in your care, particularly before adding anything alongside chemotherapy, radiotherapy or other medications. The information on this page describes what we explored and did in 2021, alongside an update on what I've learnt since. It isn't a treatment protocol and it isn't a recommendation to take any of the drugs mentioned here.

repurposed meds