Is Long-term Use of Omeprazole (Prilosec) Safe?

Omeprazole (Prilosec, Prilosec OTC) is one of the most commonly prescribed medications in the U.S. In 2021, it was the 7th most common prescription medication. But this only accounts for the prescription form of omeprazole. Omeprazole is also available over the counter (OTC), so it’s likely even more widely used.

Omeprazole can be an effective treatment for many conditions involving excessive stomach acid. It can also help lower the risk of esophagus irritation from other medications. But, it carries a risk of side effects, especially when used long term.

What is omeprazole used for?

Omeprazole is a type of medication called a proton pump inhibitor (PPI). PPIs work by blocking “proton pumps” in the stomach. These proton pumps typically make acid to help your body digest food. So omeprazole and other PPIs reduce the amount of stomach acid you have. PPIs tend to work similarly well for treating medical conditions. So experts don’t recommend one over another.

Omeprazole can treat several stomach-related conditions caused by too much stomach acid, including:

• Heartburn

• Gastroesophageal reflux disease (GERD)

• Stomach ulcers or bleeding

• Barrett’s esophagus

• Erosive esophagitis

• Helicobacter pylori (H. pylori) infection

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You may be able to treat some of these conditions with OTC omeprazole and guidance from your pharmacist. Others might require that you see a prescriber. In these cases, they may prescribe omeprazole or recommend taking it OTC.

What’s the difference between prescription and OTC omeprazole?

The biggest difference between prescription and OTC omeprazole are the available doses and dosage forms. OTC omeprazole comes as 20 mg tablets, capsules, and orally disintegrating tablets. Prescription omeprazole comes as 10 mg, 20 mg, and 40 mg capsules. There’s also 2.5 mg and 10 mg oral omeprazole granule packets that can be mixed into water. The granule packets are available by prescription only.

For OTC versions of omeprazole (such as Prilosec OTC), adults ages 18 and older can take 20 mg once a day. With prescription omeprazole, you should always follow your prescriber’s instructions. The dosage is usually 20 mg to 40 mg once a day. But there are conditions where higher or more frequent doses are recommended.

Good to know: It’s possible your prescriber may recommend using OTC omeprazole to obtain prescription-strength dosages. For example, your prescriber could recommend you take two 20 mg OTC omeprazole capsules daily to reach a total daily dose of 40 mg (a common prescription omeprazole dosage). But you shouldn’t take OTC omeprazole this way unless a healthcare professional tells you to do so.

How long should you take prescription omeprazole?

You should take prescription omeprazole for as long as prescribed. For some people, this could mean taking a 2-week course. For others, it could mean taking it long term.

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It can take several days to feel the full effects of omeprazole. So it’s important to give the medication time to improve your symptoms. To get the best results, try taking your doses about 30 to 60 minutes before a meal. This is because omeprazole is better absorbed when it’s taken on an empty stomach.

It’s recommended to take omeprazole for 4 to 8 weeks for most conditions, like GERD and stomach ulcers. But for other conditions like Barrett’s esophagus, you may need to keep taking it long term to prevent further complications — whether you have symptoms or not.

If you’re concerned about taking prescription omeprazole, talk to a healthcare professional. They can explain the risks and benefits for you.

How long should you take Prilosec OTC?

According to the package instructions, you should only take Prilosec OTC (and other brands of OTC omeprazole) for up to 14 days (2 weeks). If you need it for longer than 14 days, it’s best to check with a healthcare professional before continuing. You may have more than just heartburn going on. And a healthcare professional can advise you on the best treatment options for your symptoms.

In some cases, prescribers may recommend taking Prilosec OTC for longer than 14 days. In this case, it’s OK to continue taking Prilosec OTC based on your prescriber’s instructions. But you’ll likely need to regularly check in with them to make sure it’s still the right treatment for you.

What are the side effects of omeprazole?

Omeprazole and other PPIs tend to have similar side effects. There’s not one that seems to cause more or worse side effects than the other.

Common side effects of omeprazole include:

• Headache

• Stomach pain

• Nausea or vomiting

• Diarrhea

• Gas

Many of these side effects are mild and should resolve on their own without treatment. If you’re having side effects that are bothersome or won’t go away, let a healthcare professional know.

Side effects of long-term omeprazole use

If you take omeprazole for too long, there can be a risk of having long-term side effects.

Long-term use of omeprazole has been linked to:

• Lower bone density (weakened bones)

• Low magnesium levels

• Respiratory infections like pneumonia

• Severe diarrhea caused by the bacteria Clostridioides difficile (C. diff)

• Acid rebound (worsening of symptoms when you try to stop omeprazole)

Because of these risks, it’s best to only take omeprazole for a few weeks, or as instructed by your prescriber. But as mentioned above, sometimes the benefits of long-term omeprazole use outweigh the risks.

If long-term side effects are a concern, your prescriber may recommend an alternative treatment that would still be effective. But this depends on the condition. Sometimes, a PPI like omeprazole is the best treatment.

What happens if you stop taking omeprazole too soon?

With some conditions, it’s not dangerous to stop taking omeprazole. But it could cause you to be more uncomfortable. For example, if you’re using omeprazole for heartburn, stopping it might cause your symptoms to return or worsen.

In other cases, stopping omeprazole could be harmful. For example, if you have a condition like Barrett’s esophagus, stopping omeprazole could cause more damage to your esophagus.

If your prescriber has asked you to take omeprazole, always check with them before stopping the medication.

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Written by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

Edited by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

Reviewed by:

Amy B. Gragnolati, PharmD, BCPS

Amy Gragnolati, PharmD, BCPS, is a pharmacy editor for GoodRx. Amy currently holds her pharmacist license in Georgia and California.

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