Is Omeprazole Safe for Long-Term Use?

Omeprazole (Prilosec) is among the most prescribed drugs in the world — but growing evidence points to real risks from extended daily use.

What Is Omeprazole?

Omeprazole (brand name Prilosec) is a proton pump inhibitor (PPI) — a class of medications that reduce stomach acid production by blocking the enzyme responsible for secreting acid into the stomach. It is used to treat gastroesophageal reflux disease (GERD), peptic ulcers, erosive esophagitis, and conditions of excess acid production like Zollinger-Ellison syndrome. It is also used alongside antibiotics to treat H. pylori bacterial infections.

Omeprazole is available both by prescription and over the counter. OTC versions are intended for up to 14 days of self-treatment, but many people take PPIs continuously for months or years, sometimes without ongoing physician oversight.

Short-Term Safety

For short-term use (up to 8 weeks for most approved indications), omeprazole is well tolerated and has a favorable safety profile. Common side effects are mild and include:

• Headache
• Diarrhea or constipation
• Nausea
• Stomach pain
• Flatulence

Long-Term Risks

A growing body of research has identified several meaningful risks associated with prolonged PPI use:

Nutrient Deficiencies

Stomach acid plays a role in absorbing key nutrients. Suppressing it over the long term can lead to deficiencies in:

• Magnesium: The FDA has warned that PPIs can cause low magnesium (hypomagnesemia) after prolonged use, leading to muscle spasms, irregular heartbeat, and seizures.
• Vitamin B12: Acid is needed to release B12 from food proteins. Long-term PPI use may impair B12 absorption, particularly in older adults.
• Calcium: Reduced acid can impair calcium absorption, contributing to bone density loss over time.
• Iron: Stomach acid also aids non-heme iron absorption; PPI use may worsen iron deficiency in susceptible individuals.

Bone Fracture Risk

Multiple studies have found that long-term PPI use is associated with an increased risk of hip, wrist, and spine fractures, likely related to impaired calcium absorption and possibly direct effects on bone metabolism. The FDA added a safety communication about this risk in 2010.

Infection Risk

Stomach acid acts as a barrier against harmful bacteria. Reducing acid production can increase susceptibility to:

• Clostridioides difficile (C. diff): A serious intestinal infection associated with PPI use, especially in hospitalized or antibiotic-treated patients.
• Pneumonia: Some studies have found a modestly increased risk of community-acquired pneumonia in PPI users, possibly due to bacterial overgrowth in the upper GI tract.

Who Should Be Particularly Cautious?

• Older adults (greater susceptibility to fractures, B12 deficiency, and kidney disease)
• People with kidney disease
• Those with osteoporosis or low bone density
• People taking clopidogrel (omeprazole may reduce its effectiveness)
• Anyone on long-term antibiotics or in frequent hospital settings (C. diff risk)

Reassessing Long-Term PPI Use

Medical guidelines increasingly emphasize periodic reassessment of the need for ongoing PPI therapy. Many patients who were started on PPIs in the hospital or for a short-term indication continue taking them indefinitely. Doctors and patients should regularly discuss whether the drug is still needed, whether the lowest effective amount is being used, and whether lifestyle changes or alternative treatments might allow a taper off.

Frequently Asked Questions