Lansoprazole vs. omeprazole: How they compare

If you often experience heartburn, a symptom of acid reflux and gastroesophageal reflux disease (GERD), healthcare professionals may recommend you take lansoprazole (Prevacid) or omeprazole (Prilosec). These belong to a class of drugs called proton pump inhibitors (PPIs).

Both lansoprazole and omeprazole can be effective in managing symptoms of GERD. However, they might have different effects depending on your individual situation. You may find that one is better for you than the other. Like any drug, they may also cause some side effects.

Need a diagnosis or prescription quickly? Optum Perks offers personalized on-demand care in as little as 15 minutes. For $29, answer a few questions online and receive a diagnosis and treatment plan from a US-licensed healthcare professional. Get started here.

What are PPIs?

PPIs work to decrease acid production in your stomach. They affect the cells in your stomach that contain the enzyme — known as the proton pump — which is the final step of acid secretion into your stomach. Because of this, they’re helpful for conditions such as:

• GERD
• frequent heartburn
• esophagitis
• peptic ulcer disease

Some PPIs are available over the counter (OTC) in lower strengths. If you receive a diagnosis of a condition like GERD, doctors might also prescribe stronger ones to you. Some examples of PPIs include:

• lansoprazole (Prevacid)
• omeprazole (Prilosec)
• pantoprazole (Protonix)
• rabeprazole (Aciphex)

If you need help covering the cost of medications, the free Optum Perks Discount Card could help you save up to 80% on prescription drugs. Plus, you can now get them delivered to your home in as little as 3 days. Search for your medication here.

What to know about lansoprazole

Lansoprazole is a generic medication that’s available in OTC and prescription formulations. It’s also available under the brand name Prevacid, which comes in capsule form or as an orally disintegrating tablet.

Lansoprazole may come in different strengths. The OTC form used to manage acid reflux is 15 milligrams (mg). This type is taken once per day for 14 days. It may take up to 4 days for you to feel the full effect, but you may notice your symptoms easing within 24 hours.

The prescription form of the drug can come in different strengths depending on what it’s being used to treat. For example, to treat GERD, you’ll need to take 15 mg of lansoprazole once daily for up to 8 weeks. For erosive esophagitis, take 30 mg once daily for up to 8 weeks.

For conditions like Zollinger-Ellison syndrome, doctors may prescribe up to 60 mg.

Like any medication, lansoprazole can cause some side effects. Some of the more common ones include:

• abdominal pain
• headache
• constipation or diarrhea
• nausea

What to know about omeprazole

Omeprazole is another generic medication that is available in OTC and prescription options. Its brand name is Prilosec.

The OTC form of omeprazole is 20 mg, which you take once per day for 14 days. You may feel relief in your symptoms within 24 hours, but it may take up to 4 days to notice its full effect. It comes in tablet form.

The prescription form will also vary depending on the condition that it’s treating, and it usually comes in capsule form. For GERD, you should take 20 mg once per day for up to 4 weeks. The dose for an active benign gastric ulcer is 40 mg for 4 to 8 weeks.

For conditions like Zollinger–Ellison syndrome, doctors may start with 60 mg, but dosages up to 120 mg 3 times per day are possible.

Omeprazole may also cause side effects. These include:

• headache
• constipation or diarrhea
• vomiting
• gas

What are the differences between lansoprazole and omeprazole?

Lansoprazole and omeprazole are very similar medications. However, they have some key differences:

• Dose: While the general treatment length with both drugs is the same, the dose of lansoprazole starts at 15 mg, whereas for omeprazole, it’s 20 mg.
• Drug form: The OTC version of lansoprazole is a capsule, whereas the OTC form of omeprazole is a tablet.
• Side effects: Although both drugs may cause similar side effects, you might find that they affect you differently. One form may not cause side effects, or the effects may be less significant.
• Cost: The two drugs may differ in cost, whether OTC or prescription. According to a 2018 study, 15 mg of lansoprazole is slightly cheaper than 20 mg of omeprazole, although the difference isn’t much.

Which one to choose

If you have a condition like GERD or a stomach ulcer, a doctor will prescribe the medication that they feel is best for you. However, if you’re using OTC formulations, you can choose which drug you would like to try.

You may wonder whether one is more effective than the other. However, according to a 2024 review, the two drugs have no difference in effectiveness in reducing heartburn and reflux symptoms. But omeprazole may be slightly better at healing ulcers than lansoprazole.

You may also consider factors like cost and availability when deciding which medication to choose. Since there is little difference in the effectiveness of the medications, you can consider cost and which one is easier to find in pharmacies or stores.

You can speak with a healthcare professional such as a doctor or a pharmacist if you don’t know which is better. They can advise or reassure you about your choice. You can do this in person or through online care.

Online care services, including Optum Perks Online Care, may make getting treatment easier. With these services, you can submit an online form answering a few questions about your symptoms, and a US-licensed healthcare professional will respond soon after to prescribe a treatment plan.

Summary

Lansoprazole and omeprazole are both generic medications that belong to the class of drugs known as PPIs. They have similar effectiveness, and both work similarly to reduce stomach acidity and heartburn symptoms.

The best drug for you will depend on your individual situation. Doctors might prescribe one or the other depending on what they feel is best for your condition. If one doesn’t seem to work, they may switch to another.

Download the free Optum Perks Discount Card to save up to 80% on many prescription medications. Plus, you can now get them delivered to your home in as little as 3 days. Search for your medication here.