Omeprazole: Uses, Side Effects, and How to Take It
Omeprazole is a proton pump inhibitor, a type of medicine that reduces acid production in the stomach. It is used to treat frequent heartburn, acid reflux, stomach ulcers, and reflux-related damage to the esophagus, and it may be used with antibiotics for certain ulcer infections.
Omeprazole can relieve acid-related symptoms, but it is not intended for immediate relief and usually needs several days to work. Follow the prescribed directions or package label, and ask a doctor or pharmacist if you are unsure whether it is right for you.
Key facts at a glance
- ATC
- A02BC01
- Generic
- Omeprazole
- Class
- proton-pump-inhibitor
- Brands
- Prilosec, Losec
- Availability
- behind_counter
- Pregnancy
- C
- Lactation
- caution
- Half-life (h)
- 1
- Onset (min)
- 60
- Duration (h)
- 72
- Routes
- oral, iv
- Forms
- capsule, tablet, injection
- Regions
- CN, US, EU, JP
- Monitoring
- magnesium, vitamin-b12
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 20-40mg once daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 0.5-1mg/kg once daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 20mg once daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
10 groupspregnancy
first trimesteruse lowest effective dose
use only if clearly needed and benefits outweigh potential risks
regular prenatal monitoring
Use with caution and monitor for adverse effects.
pregnancy
second trimesteruse lowest effective dose
continue only if benefits justify risks
routine prenatal care
Use with caution and monitor for adverse effects.
pregnancy
third trimesteruse lowest effective dose
discontinue before delivery if possible
fetal monitoring
Use with caution and monitor for adverse effects.
lactation
not applicableno adjustment needed
considered compatible with breastfeeding
monitor infant for unusual symptoms
pediatric_age
children 1 year and olderweight-based dosing
use pediatric formulation; do not exceed recommended dose
monitor growth and symptoms
geriatric
not applicableno standard adjustment required
start at low end of dosing range; monitor renal function
periodic renal function monitoring
renal_impairment
mild to moderateno adjustment needed
standard dosing appropriate
routine monitoring
renal_impairment
severeconsider dose reduction
use caution; monitor for adverse effects
close monitoring of renal function and symptoms
Use with caution and monitor for adverse effects.
hepatic_impairment
mild to moderatedose reduction may be needed
monitor liver function; reduce dose if needed
periodic liver function tests
Use with caution and monitor for adverse effects.
hepatic_impairment
severereduce dose to 10-20mg daily
use lowest effective dose; monitor closely
regular liver function monitoring
Use with caution and monitor for adverse effects.
Statistics and clinical data
Commonly prescribed since
General prescribing information
Drug class
Drug class information
Common uses
Common therapeutic uses
Mechanism of action
Pharmacological mechanism
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
WellAlly may earn a referral fee from linked resources at no extra cost to you. Editorial content is never influenced by commercial relationships.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 22, 2026. · Read our editorial policy