Go to the doctor with persistent symptoms of acid reflux, and you’ll commonly be prescribed a PPI like omeprazole. They’re widely used, effective, and considered largely safe. Some people take PPIs for years or even decades. But are there any dangers of long-term use of proton pump inhibitors?

That’s the question medical professionals are increasingly asking.

The first PPIs were developed in the 1980s, with omeprazole being launched in 1988. However, we couldn’t study the real long-term effects until patients had been on them for decades. New evidence points to some risks associated with long-term PPI use. But it’s important to understand the context.

Below, we look at what the evidence actually shows, where concerns exist, and why you shouldn’t panic.

What Are PPIs and Why Are They Prescribed?

PPIs, or proton pump inhibitors, are medications that are used to reduce stomach acid production. As the name indicates, they block the proton pumps in the stomach that directly produce acid.

They’re commonly prescribed for:

• Acid reflux (GERD)

• Peptic ulcers

• H. pylori treatment

Excess acid production is also a common side effect of other medications. So, you might find your doctor prescribes a PPI as standard to “protect the stomach.” This is normal medical practice.

Are PPIs Safe for Long-Term Use?

At first glance, PPIs are extremely safe. The incidence of short-term adverse events is relatively low. Even long-term, PPIs have a low risk of harmful effects. And while some reviews have noted potential links to harmful conditions, the overall quality of the evidence is “low” or “very low.” That means it’s hard to establish a causal relationship.

That being said, there are some risks. As with any medications, it’s best to avoid taking them if possible. Unnecessary prolonged use should be minimised unless there’s a clear indication.

What 20+ Years of Research Shows About Long-Term PPI Use

Unfortunately, even with 20 years of research, the overall quality of evidence for each potential adverse effect is poor. The existing data shows some moderate effect size for conditions like kidney disease, dementia, Clostridium difficile infection, and micronutrient deficiencies.

That means that while there is a potential link, it’s not well-established. If a risk does exist, it’s probably quite small, and there should be hesitancy about stating a definite causal relationship. Studies try to account for other factors, but over 20 years, confounding factors influence whether negative outcomes occur or not.

Potential Risks of Long-Term PPI Use

Gut Microbiome Changes

Stomach acid doesn’t just break down food; it also helps control which bacteria survive in the gut. When acid levels are reduced over long periods, this balance can shift. Some studies suggest PPIs are associated with reduced microbial diversity and an overgrowth of less beneficial bacteria.

While the clinical impact isn’t always clear, these changes may help explain the increased risk of certain infections and digestive issues seen with long-term use.

Nutrient Deficiencies

PPIs appear to reduce the absorption of vitamin B12, magnesium, and calcium. Long-term, it’s possible that prolonged B12 deficiencies cause anaemia and that low calcium affects bone density.

Increased Risk of Infections

Stomach acid is produced by your body to fight off infections. With less acid, there’s reduced defence against pathogens. That slightly increases the risk of C. difficile and other gastrointestinal infections.

Bone Health and Fracture Risk

Reduced calcium absorption can affect bone health. While short-term PPI use is unlikely to have an effect, calcium is necessary long-term for the repair and strengthening of bones. The highest fracture risk occurs in older adults, especially post-menopausal women.

Kidney Disease and Other Associations

Some studies have observed a link to chronic kidney disease and dementia. However, the evidence for both connections is low quality.

How to Reduce Risk If You’re Taking PPIs Long Term

The advice is simple: PPI use should be continually reviewed by your doctor. The doctor can reassess if it’s still needed, if the lowest effective dose is being used, and if it’s causing any adverse effects.

You should not suddenly stop taking PPIs as this can cause an acid rebound effect. Instead, the dose should be lowered incrementally with the help of your healthcare professional.

If you’re dealing with ongoing heartburn or reflux, it’s worth looking at the underlying cause rather than guessing. The Functional Gut Clinic offers targeted testing for GERD and acid reflux to assess what’s really driving your symptoms. From there, your doctor can give you clear, personalised guidance on diet, lifestyle, and treatment options to help bring things under control.

Read the next article: Apple Cider Vinegar for Heartburn: Does the Evidence Hold Up?