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Omeprazole (Serum/Plasma Concentration)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of omeprazole, a medication used to reduce stomach acid, in your blood.

Quick summary

["Omeprazole levels help doctors check if your dose is working properly and adjust it if needed."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
72982-2
Short code
Omeprazole (neut) IgG SerPl Ql FC
Synonyms
Omeprazole (neut) IgG SerPl Ql FC
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
CPT
82784
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your healthcare provider may order this test if you’re taking omeprazole (a proton pump inhibitor) for conditions like acid reflux, ulcers, or heartburn. It helps ensure the medication is at the right level in your blood to treat your symptoms effectively without causing side effects.

What to Expect Before the Test

No special preparation is usually needed. You may have a small needle inserted into a vein (venipuncture) in your arm to draw blood. If you’re on a long-term omeprazole regimen, your levels may be checked periodically to monitor your response.

What the Results Mean

Results provide a snapshot of your current omeprazole concentration. While reference ranges can vary by lab, they help guide whether your dose is therapeutic or if adjustments are needed. Your doctor will interpret these results in the context of your overall health and treatment plan.

Common Reasons for Testing

Doctors may test omeprazole levels if you’re experiencing side effects (e.g., fatigue, confusion), if your symptoms aren’t improving, or if you’re taking other medications that could interact with omeprazole.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Omeprazole Level

Frequently asked questions

What does a low or high omeprazole level indicate?
Low levels may suggest your dose isn’t sufficient to control stomach acid, while high levels could indicate improper dosing, liver issues, or interactions with other medications. Your doctor will assess these results alongside your symptoms and medical history to adjust your treatment plan.
How often should I have this test?
The frequency depends on your treatment plan. If you’re on a short-term course, testing may occur at specific intervals (e.g., 2–4 weeks). For long-term use, your doctor may check levels less often (e.g., every 3–6 months) or as needed to monitor for side effects or interactions.
Can I stop taking omeprazole before the test?
No, do not stop taking omeprazole without consulting your doctor. Skipping doses or stopping abruptly can lead to withdrawal symptoms or worsening acid-related conditions. Your doctor will guide you on timing for the test.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

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 August 16, 2026. · Read our editorial policy