The ‘chemo brain’ supplement that could beat brain fog and fatigue: Users swear by it… and now scientists share promising evidence it could actually help

The claims – about a little-known supplement, written in their hundreds on online forums – make for compelling reading.

‘I feel like a brand-new person,’ wrote one user, while another described how a crushing ‘backpack of fatigue’ had lifted within just three days of starting to take it.

Others insist the remedy is ‘the only thing that’s ever worked’ to relieve their debilitating exhaustion and brain fog.

At the centre of these extraordinary accounts is an unlikely ingredient: oxaloacetate, a compound produced naturally by the body that helps our cells generate energy.

It’s hardly a household name. Yet scientists are beginning to investigate whether it could offer fresh hope to people suffering from debilitating problems with memory, concentration and fatigue.

And now, encouraging new research suggests there may be something in the claims.

In a small study published this week, US scientists found that breast cancer survivors who took oxaloacetate for eight weeks reported remarkable improvements in the memory and concentration problems they had experienced following treatment.

All 16 women who completed the study reported improvements, with their average scores on a measure of cognitive difficulties moving from a range considered impaired to one considered normal.

And the benefits weren’t limited to how they felt. Tests also suggested improvements in their ability to process information, concentrate and make decisions.

The findings raise the tantalising possibility of a new treatment for brain fog – the umbrella term for difficulties with memory, concentration and thinking that can have a devastating impact on everyday life.

But experts caution that the evidence remains preliminary, and larger studies are needed to establish whether the supplement really works.

For those living with brain fog, the impact can be devastating.

Often associated with conditions such as long Covid and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), it can leave sufferers struggling to follow conversations, remember information or carry out everyday tasks.

‘Some people manage to cope with brain fog, but for others it’s very disabling,’ says Dr Charles Shepherd, honorary medical adviser to the ME Association and a leading voice on issues such as fatigue and brain fog.

‘We have no effective proven treatment at the moment, so people are desperate.’

And some of those who have tried oxaloacetate describe remarkable results.

Writing on the social media site Reddit, one long Covid sufferer who said they had taken part in an oxaloacetate trial claimed to notice a difference within days.

‘After three days taking 500mg twice a day, the feeling like I was carrying a backpack of fatigue rocks lifted,’ they wrote.

‘Did I still get fatigued and have to be careful of doing too much? Yes, but that overwhelming weight of fatigue lifted.

‘My brain fog and concentration problems began to lift.’

Others living with ME/CFS, a long-term illness that can cause extreme exhaustion and cognitive difficulties, have reported similar experiences.

One parent claimed the supplement had a ‘dramatic positive effect’ on their daughter’s fatigue and brain fog.

They described how she went from rarely leaving the house and struggling to read for more than a few minutes to studying for several hours a day, travelling independently and returning to a near-normal life.

Of course, these accounts cannot be independently verified, and there is no way of knowing whether oxaloacetate was responsible for the improvements.

But they have caught the attention of researchers investigating whether the supplement might genuinely help people struggling with cognitive problems.

And the latest findings offer some intriguing clues.

The most recent study, published this week in the journal JCO Oncology Advances, was led by researchers at the University of California, Los Angeles (UCLA).

Scientists recruited 18 breast cancer survivors who were experiencing significant problems with memory, concentration and thinking – symptoms sometimes referred to as ‘chemo brain’.

These difficulties can persist for years after cancer treatment, affecting an estimated 15 to 25 per cent of breast cancer survivors.

The women, whose average age was around 50, were given 500mg of oxaloacetate twice daily for eight weeks.

Of the 16 who completed the study, all reported improvements in their cognitive symptoms.

Strikingly, their average scores on a questionnaire measuring perceived memory and thinking difficulties rose from 29.1 to 55.5 – moving from a level considered impaired to one within the normal range.

And the benefits weren’t limited to how the women felt.

Standardised cognitive tests also showed improvements in their ability to process information quickly, concentrate, plan and make decisions.

Participants reported feeling less tired and experiencing improvements in their physical functioning, too.

‘These early findings give us a strong reason to continue studying oxaloacetate as a potential approach for managing cognitive problems after breast cancer treatment,’ said Dr Patricia Ganz, a professor of medicine at UCLA who led the research.

However, there are important caveats.

The study was small and did not include a placebo group, meaning researchers cannot be certain that oxaloacetate was responsible for the improvements.

It is also possible that some of the gains on cognitive tests reflected participants becoming more familiar with them.

Two women stopped taking the supplement because of digestive side effects, including symptoms such as nausea and bloating.

The UCLA team is now preparing a larger, placebo-controlled trial to establish whether the promising results can be replicated.

And while the findings are encouraging, this is not the first study to suggest oxaloacetate could have benefits for people struggling with brain fog.

In a separate study published last year in the journal Frontiers in Neuroscience, researchers at the Bateman Horne Center in Utah tested oxaloacetate on 69 adults suffering from long Covid.

Unlike the UCLA research, this was a placebo-controlled trial, meaning some participants received the supplement while others were given a dummy pill, allowing scientists to make a more reliable assessment of its effects.

Those taking oxaloacetate received around 2,000mg daily for three weeks.

The results were mixed.

The study’s main aim was to establish whether the supplement could reduce fatigue. On this measure, researchers found no statistically significant difference between the two groups.

However, those taking oxaloacetate performed better on certain cognitive tests, suggesting it might help with the memory and concentration difficulties associated with brain fog.

There were also encouraging findings on some secondary measures of fatigue and symptom burden, although these are less conclusive than the study’s primary result.

Other research involving patients with ME/CFS has also suggested that oxaloacetate may help reduce fatigue, adding to scientists’ interest in the compound.

But experts stress that the findings remain preliminary, and larger trials are needed to establish who might benefit, at what dose and for how long.

So why might oxaloacetate help?

Penny Ward, a professor of pharmaceutical medicine at King’s College London, explains that the compound plays an important role in the chemical reactions that allow cells to generate energy.

One theory is that disturbances in these processes may contribute to the exhaustion and cognitive difficulties experienced by some patients.

Supplementing oxaloacetate could potentially help restore more normal cellular energy production, although this has yet to be demonstrated as the reason for the improvements seen in clinical trials.

‘Given the poverty of treatments for this, one would have thought that would be of interest enough for somebody to explore it in more detail,’ Professor Ward says.

Dr Shepherd believes there may be another explanation.

Oxaloacetate could also influence inflammation in the body, including neuroinflammation – inflammation affecting the brain and nervous system – which researchers suspect may play a role in some forms of fatigue and brain fog.

‘There’s a positive theoretical reason why something like this might work,’ he says.

‘We need more information on it before drawing any conclusions, but my hope is that people who are capable of doing larger clinical trials will look at this and say, “yeah, this is worth following up”.’

But for anyone tempted to try oxaloacetate, there are some important practical considerations.

The supplement is available to buy online in Britain, although taking it at the doses used in clinical trials could prove extremely expensive.

One product, BenaGene, costs around £43 for 30 capsules containing 100mg of oxaloacetate each.

At the 1,000mg daily dose used in the UCLA study, this would mean taking ten capsules a day, costing more than £400 a month.

Higher-strength formulations are also available, including a product called Oxaloacetate CFS, which contains 500mg per capsule and is sold by an American manufacturer that ships internationally.

However, at around $500 (£370) for 90 capsules, an eight-week supply at the dose used in the UCLA study would cost almost $1,000, (£745) before shipping and any import charges.

And there is another significant unknown.

Scientists have yet to establish whether patients would need to take oxaloacetate indefinitely to maintain any benefits, or whether a short course might be sufficient.

The latest study lasted just eight weeks, and it remains unclear whether the improvements persisted once participants stopped taking the supplement.

Nor is it certain that different commercially available formulations would produce the same results as those used in clinical trials.

Although oxaloacetate was generally well tolerated in the studies, some participants experienced digestive problems, including nausea, bloating and diarrhoea.

Experts therefore caution that it is too early to recommend the supplement as a treatment for brain fog.

For now, the findings offer an intriguing possibility rather than a proven solution – but one that researchers believe deserves further investigation.