Medication taken by millions of Britons to relieve heartburn and acid reflux can have a harmful impact on digestion in the long term, a top pharmacist has warned.

Deborah Grayson, dubbed the ‘Godmother of Pharmacology’, took to TikTok to discuss how omeprazole—a proton pump inhibitor (PPI)—can affect gut health.

In the video, which has had more than 42,000 views, Mrs Grayson said that while the drugs may offer sufferers momentary relief, they could also cause problems—leading to bloating and nausea, weight gain and vitamin deficiencies.

PPIs are one of the UK’s most prescribed mediations in the UK, with 73 million NHS prescriptions dispensed in England in 2022-23, at a cost of £190m.

She explained: ‘Omeprazole stops heartburn and reflux, but how does it really work? It’s a PPI, and that interferes with the cells of the stomach responsible for producing stomach acid.

‘So, if we stop the stomach from producing acid—by taking a PPI—the theory is that we will stop the acid coming back into the oesophagus and causing heartburn and reflux.

‘There’s often a discussion about whether heartburn is related to low or high stomach acid. But actually it’s to do with the timing of the stomach acid.

‘While stopping your stomach producing that acid can be beneficial in the short term, it’s not always great for your digestion in the longer term as we need that acid to break down our food.

 Acid reflux happens when stomach acid flows back into the oesophagus (file photo)

Lansoprazole is a type of medicine called a proton pump inhibitor

‘It can be helpful to have omeprazole if you’ve got gastritis or erosion in your oesophagus, but if you’ve only got simple heartburn-related problems, longer term it can have greater impacts on the body.’

Acid reflux happens when stomach acid flows back into the oesophagus, often causing heartburn—a burning sensation in the chest or throat.

Normally, a valve called the lower esophageal sphincter prevents this, but if it weakens or relaxes at the wrong time, acid can escape and irritate the oesophagus.

Triggers include stress, excess weight, eating too quickly, or consuming alcohol, caffeine and chocolate. Pregnancy hormones can also raise the risk.

While reflux is uncomfortable, stomach acid is essential for digestion. It activates pepsin, an enzyme that breaks down proteins, and helps soften food. It also protects against harmful microbes in food.

Mrs Grayson said low stomach acid may increase infection risk and hinder absorption of key nutrients like Vitamin B12, iron, calcium and magnesium.

Mrs Grayson, who has been working as a pharmacist for 30 years, and also runs Practice With Confidence, teaching transformative patient care, said: ‘Long-term use of PPIs can significantly impair digestion.

‘Stomach acid plays a crucial role in breaking down food, particularly proteins, and activating enzymes like pepsin.

‘When acid levels are too low, food may not be properly digested, leading to symptoms such as bloating, nausea, abdominal discomfort, and IBS-like issues including flatulence, constipation, or diarrhoea.

‘Poor digestion may also contribute to nutrient malabsorption, potentially leading to fatigue or weight fluctuations.

‘Reduced stomach acid can also compromise the gut’s natural defense barrier, increasing susceptibility to infections such as Clostridium difficile, Campylobacter and small intestinal bacterial overgrowth (SIBO).

‘These can cause further gastrointestinal symptoms and, in some cases, serious complications.’

Under her TikTok handle @tgopharm, Mrs Grayson explained in a previous video that if you’re a frequent sufferer of acid reflux and heartburn, lifestyle changes can make a real difference.

Taking the time to eat slowly and mindfully is essential for proper digestion. If you’re too busy to cook, Mrs Grayson suggested starting the ‘anticipation process’ around 20 to 30 minutes before eating.

She said: ‘Think about what you are going to have, how it tastes and how it smells. This can trigger the anticipatory response in the same way that preparing it yourself would have done.

‘Modern lifestyles have resulted in many people deciding they are hungry, dashing into the nearest food outlet and eating food within minutes. ‘This means that the body has to play catch up, exacerbating symptoms.’

In another video shared on her platform, Mrs Grayson recommended ‘disconnecting from technology and doing some alternate nostril breathing’ – which can help with switching on your digestion and reducing reflux.

She also said to avoid trigger foods, such as peppermint, chocolate, coffee, citrus and tomatoes and leave a gap between eating and sleep, as lying down with a full stomach can trigger reflux.

Mrs Grayson said a window of three hours between your final meal and bedtime is optimal.

The pharmacist has previously spoken about the damaging impact of omeprazole, discussing how it can make symptoms worse in the long-run and can make someone become dependent on it.

She said: ‘We are sleepwalking into a significant culture of PPI addiction due to over-prescribing without clear reason and failure to give patients a clear exit strategy from the treatment.’

Research shows up to 40 per cent of patients do not respond to a PPI, so the drug is rendered useless in those cases.