Compare omeprazole vs. Prevacid

Head-to-head comparisons of medication uses, side effects, ratings, and more.

Prilosec (omeprazole)

Prescription or OTC

Prevacid (lansoprazole)

Prescription or OTC
Treats heartburn and excess release of stomach acid.

Prilosec (omeprazole) gives you long-lasting heartburn relief but has some risks if used long term.

4.0/ 5 average rating with 1167 reviewsforomeprazole
Treats heartburn and stomach ulcers.

Prevacid (lansoprazole) is an effective and inexpensive acid reducer commonly used to provide heartburn relief and help heal ulcers.

4.0/ 5 average rating with 21 reviewsforPrevacid
  • Prilosec (omeprazole) lasts longer (up to 72 hours) than other classes of acid reducers (like Zantac, Pepcid, or Tums).
  • Only take once or twice daily.
  • Can take together with a quick-acting antacid (like Maalox or Tums) for quick relief.
  • Generic and over-the-counter options available.
  • Safe to use in children ages 1 or older.
  • Most people can take Prevacid (lansoprazole) without any noticeable day-to-day side effects.
  • Comes in a dissolving tablet to be placed on the tongue if you cannot or do not like to swallow pills.
  • Prevacid (lansoprazole) lasts longer than other types of antacids (like Zantac, Pepcid, or Tums), and you only need to take it once a day.
  • You can take it in combination with a quick-acting antacid (like Maalox or Tums) if you need relief right away.
  • Prevacid (lansoprazole) is available over-the-counter and as inexpensive, generic options.
  • Takes up to an hour to start noticing the effects of Prilosec (omeprazole).
  • Prilosec (omeprazole) can interact with other drugs. Let your doctor and pharmacist know what medications you're taking before starting Prilosec (omeprazole).
  • Long-term use of Prilosec (omeprazole) can put you at risk for many health issues such as osteoporosis, low magnesium or vitamin B12 levels, and rebound acid secretion (where your body starts to create more acid than before after stoping Prilosec (omeprazole)).
  • Doesn't start working right away like some other acid reducers (Tums, Rolaids, or Maalox).
  • May not be the best choice for patients 65 years of age and older due to risk of bone fractures and C. diff infection (bacterial).
  • Is used if you have frequent heartburns that occur more than 2 days per week. Speak to your doctor or pharmacist if you only have occasional heartburn.
Used for
Dosage forms
  • Pill
  • Powder
  • Extended release
  • Dissolving tablet extended release
  • Liquid
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1167 reviews so far
saidit'sworth it
saiditworked well
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Have you used Prilosec (omeprazole)?

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21 reviews so far
saidit'sworth it
saiditworked well
saidit'sa big hassle

Have you used Prevacid (lansoprazole)?

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Side effects
11possible side effects
  • Headache
  • Abdominal pain
  • Nausea
  • Diarrhea
  • Vomiting
  • Flatulence
  • Acid regurgitation
  • Upper respiratory infection
  • Constipation
  • Dizziness
  • Rash
See more detailed side effects
2possible side effects
  • Diarrhea
  • Abdominal pain
See more detailed side effects
Risks and risk factors
  • Risk of cancer
  • Lupus
    • History of cutaneous or systemic lupus erythematosus
  • Severe diarrhea associated with C.difficile infection
    • Being hospitalized
    • Antibiotic use
  • Bone fractures
    • Osteoporosis
    • Using high medication doses
    • Long-term therapy (1 year or more)
    • Use of other medications that weaken bones
  • Low Vitamin B12 and Magnesium
    • Taking water pills (Magnesium)
    • Women (Vitamin B12)
    • Over the age of 30 (Vitamin B12)
  • Kidney damage
See more detailed risks and warnings
  • Stomach cancer
  • Acute kidney damage
  • Clostridium difficile associated diarrhea (CDAD)
  • Bone fractures
    • High dose Prevacid (lansoprazole)
    • Long-term treatment with Prevacid (lansoprazole)
    • Low bone mineral density
    • Older age
  • Lupus
  • Low vitamin or mineral levels
See more detailed risks and warnings