It’s the over-the-counter supplement costing as little as 30p, a tablet that health influencers claim can help you resist the urge to drink too much alcohol this Christmas.
Social media is buzzing with excitement over L-glutamine, available from health food shops and online as a tablet or powder, and its reputation for curbing sugar and alcohol cravings – as well as bolstering gut health and even reducing stress.
Instagram and TikTok clips proclaiming its anti-alcohol effects have been viewed millions of times.
And, at the time of year when two-thirds of Britons say they drink more than usual, leading to a spike in alcohol-related hospitalisations, such a remedy could prove invaluable.
But can L-glutamine really help you avoid overindulging during the festive period? Are there other supplements that could help too?
L-glutamine is an amino acid, the building blocks of the proteins our bodies need to function properly, especially our digestive and immune systems.
We make some of it ourselves but also get much of what we need from foods such as red meat, chicken, eggs, milk, nuts, red cabbage and porridge.
But the first evidence that L-glutamine might help to curb alcohol cravings, possibly by altering the balance of chemicals in the brain, emerged almost 30 years ago.
Scientists at the University of Missouri in the US studied rats that had been routinely exposed to alcohol for ten days to see if their cravings subsided after an injection of L-glutamine.
The results, published in 1998, showed although the rats ate the same amount of food and drank the same amount of water after the jab, their alcohol intake nose-dived.
Researchers said although it worked, the experiments involved injecting L-glutamine into the bloodstream. Whether it has the same effect in humans who swallow it as a capsule or powder is less clear, according to some UK experts.
‘There’s a lot of anecdotal evidence – rather than robust scientific evidence – that L-glutamine can help reduce alcohol cravings,’ says Dr Adarsh Dharendra, a consultant psychiatrist who specialises in addiction problems at the private Priory Group.
‘It’s a naturally-occurring amino acid found in foods like spinach, nuts, meat and fish.
‘It helps to keep blood sugar levels steady, reducing the energy dips that can trigger alcohol and sugar cravings.
‘And it also seems to help increase levels of the brain chemical GABA.’
GABA, or gamma-aminobutyric acid, is a chemical produced by the brain to create a calming effect to combat stress, anxiety and fear – all of which can increase the temptation to drink.
The brain needs L-glutamine to make this chemical.
But Dr Dharendra believes that, to significantly impact alcohol consumption, L-glutamine – which can be purchased at many high street chemists for around £20-a-month – needs to be taken alongside healthy lifestyle choices.
‘You’d probably have to combine it with healthy eating, adequate sleep and regular physical activity in order to get any significant effect,’ he says.
And L-glutamine is not without risks.
‘It can cause bloating, constipation and dizziness and it can interact with some prescription medicines – such as anticonvulsants used in epilepsy,’ says Dr Dharendra.
‘People with liver or kidney problems should also be especially careful, as it could make them worse.’
However, L-glutamine isn’t the only popular supplement that could make alcohol less appealing.
A 2017 German study found heavy drinkers were more likely to relapse if they had low levels of calcium – a nutrient found in milk and vitamin pills – in their bloodstream.
While commonly understood to help boost bone health, calcium is thought to improve performance in parts of the brain responsible for controlling cravings.
Researchers from Mannheim and Heidelberg universities said: ‘Calcium supplementation could be a useful intervention for decreasing cravings.’
A month’s supply of calcium tablets can be bought at Boots pharmacy for less than £6-a-month.
Even just tucking into a pot of probiotic yogurt could help, according to an animal study in 2024 study in China.
It found the higher the intake of Lactobacillus casei – the probiotic added to yogurt brands such as Actimel (which costs around 40p a pot) – the lower the consumption of alcohol.
Scientists said they think it works by promoting a healthier gut, which may in turn have a positive effect on the brain’s ability to resist tempting drinks.
They added: ‘Lactobacillus casei may be able to serve as a potential target for the prevention and treatment of alcohol abuse.’
