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Tacrolimus concentration in whole blood (1-hour post-dose)

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

This test measures the amount of tacrolimus, a medication used to prevent organ rejection after a transplant, in your blood one hour after you took your dose. It helps doctors monitor how well your body is processing the drug at that specific time.

Quick summary

["This test helps ensure your medication levels are safe and effective for transplant patients."]

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

Key facts at a glance

LOINC
92730-1
Short code
Tacrolimus 1h p Bld-mCnc
Synonyms
Tacrolimus 1h p Bld-mCnc
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test if you’re on tacrolimus therapy to check how your body is responding to the medication right after you take it. It’s particularly important for patients who’ve had an organ transplant to prevent rejection and manage side effects.

What Does This Test Tell You?

The test measures the concentration of tacrolimus in your blood at a specific time (1 hour post-dose). This helps doctors determine if your dose is too high or too low, ensuring you get the right amount of medication for your condition.

How Is This Test Performed?

A small blood sample is taken from a vein in your arm. The sample is then sent to a lab for analysis using a specialized method to measure tacrolimus levels accurately.

What Are the Results?

Results are typically reported as a concentration value (in ng/mL or similar units) and compared to target ranges recommended for your condition. Your doctor will discuss these results with you.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Tacrolimus Blood Level (1 Hour Post-Dose)

Frequently asked questions

What does a tacrolimus blood level test measure?
This test measures the concentration of tacrolimus, a medication, in your blood one hour after you take your dose. It helps doctors monitor how well your body is processing the drug at that specific time.
Why is a 1-hour post-dose level important?
A 1-hour post-dose level provides a snapshot of how quickly your body absorbs and processes tacrolimus. This timing helps doctors adjust doses to avoid both underdosing (which may lead to organ rejection) and overdosing (which can cause serious side effects).
How often should I expect this test?
The frequency of this test depends on your medical condition, transplant status, and how your body responds to tacrolimus. Your doctor will determine the schedule, which may vary from weekly to monthly or as needed for adjustments.
  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