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Paracetamol (Acetaminophen) Immunoassay, Quantitative, Plasma

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

This test measures the amount of acetaminophen (also called paracetamol) in your blood, typically after an overdose or to monitor long-term use.

Quick summary

["Acetaminophen is a common pain reliever, but high levels can be dangerous."]

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

Key facts at a glance

LOINC
73547-2
Short code
APAP ind plt IgM SerPl Ql FC
Synonyms
APAP ind plt IgM SerPl Ql FC
Category
hematology
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 Might Be Done

Your healthcare provider may order this test if you’ve taken a large dose of acetaminophen, if you’re taking it for a long time, or if you have liver concerns. It helps check for potential liver damage from acetaminophen exposure.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm. If you’re taking acetaminophen regularly, your provider may ask you to stop temporarily for accurate results.

What the Results Mean

Results are compared to standard reference ranges for acetaminophen in plasma. High levels may signal liver strain or toxicity, while low levels confirm safe exposure. Your provider will interpret results based on your medical history and symptoms.

Common Causes of Abnormal Results

Elevated levels can occur from accidental overdose, intentional poisoning, or long-term use at doses higher than recommended. Low levels may indicate recent ingestion or poor absorption.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Acetaminophen Level

Frequently asked questions

How long does it take to get results from this test?
Results are typically available within 24 to 48 hours, depending on your lab’s processing schedule. Your healthcare provider will contact you once they have the results.
Can I take acetaminophen before or after this test?
If you’re taking acetaminophen regularly, your provider may instruct you to stop taking it for a few days before testing to get an accurate measurement. Follow their guidance exactly.
What are the most common side effects of acetaminophen?
Acetaminophen is generally safe when used as directed, but high doses can cause liver damage. Common side effects at normal doses include stomach upset, nausea, or dizziness. Always follow the recommended dosage.
  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