esomeprazole vs omeprazole

PlainMeds reviewed this comparison against our methodology in August 2026. It places FDA and CMS record fields side by side, without recommending either medication.

Side-by-side comparison of esomeprazole and omeprazole. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

Drug Class
esomeprazole Proton Pump Inhibitor (PPI)
omeprazole Proton Pump Inhibitor (PPI)
Type
esomeprazole Over-the-Counter
omeprazole Over-the-Counter
Summary
esomeprazole

Esomeprazole (Nexium) is a drug that reduces stomach acid. It belongs to a class of drugs called proton pump inhibitors (PPIs).

omeprazole

Omeprazole (Prilosec) is a medicine that reduces the amount of acid in your stomach. It belongs to a class of drugs called proton pump inhibitors (PPIs).

What It Treats
esomeprazole

This medicine treats frequent heartburn. Frequent heartburn means you have heartburn 2 or more days a week. This medicine is not for immediate relief of heartburn. It may take 1 to 4 days to work fully.

omeprazole

This medicine treats frequent heartburn, which is heartburn that occurs 2 or more days a week. It is not meant to give you immediate relief from heartburn. It may take 1 to 4 days for the medicine to fully work.

How It Works
esomeprazole

Esomeprazole works by reducing the amount of acid your stomach makes. It blocks the proton pump in your stomach lining. This pump is responsible for producing stomach acid.

omeprazole

Omeprazole works by blocking the production of acid in your stomach. It does this by targeting the cells that make stomach acid. This helps to reduce heartburn symptoms.

Common Side Effects
esomeprazole
  • Nausea
  • Diarrhea
  • Headache
omeprazole
  • Headache
FAERS Reports
esomeprazole
  • Chronic Kidney Disease 5,020
  • Acute Kidney Injury 4,563
  • Nausea 4,004
  • Diarrhoea 3,869
  • Fatigue 3,528
omeprazole
  • Fatigue 19,901
  • Nausea 19,842
  • Diarrhoea 19,627
  • Dyspnoea 16,336
  • Headache 14,629
Serious Warnings
esomeprazole

Do not take this medicine for more than 14 days, or more often than every 4 months, unless your doctor tells you to.

omeprazole

Children under 18 should ask a doctor before use. Heartburn in children may be a sign of a serious condition.

Pregnancy
esomeprazole

Tell your doctor if you are pregnant or plan to become pregnant. Also, tell your doctor if you are breastfeeding or plan to breastfeed.

omeprazole

Talk to your doctor if you are pregnant or breastfeeding before taking this medicine. It is important to weigh the benefits and risks with your doctor.

Also Compare, Nearby Drugs

How to Read This esomeprazole vs omeprazole Comparison

esomeprazole is classified in the Proton Pump Inhibitor (PPI) drug class, while omeprazole sits within the Proton Pump Inhibitor (PPI) class. Because both drugs share the same classification, they are often considered interchangeable in theory, but clinical outcomes rarely track that cleanly. Both drugs are available over the counter.

Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, esomeprazole has 20,984 submissions while omeprazole has 90,335. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot represent individual circumstances. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This registry does not provide medical, treatment, substitution, or medication-change directions for esomeprazole or omeprazole.

Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.