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Carnitine (Long-Chain) Mass Concentration in Serum or Plasma

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

This test measures the amount of long-chain fatty acids bound to carnitine in your blood, which helps your body use energy and remove waste products.

Quick summary

["Long-chain carnitine levels can indicate how well your metabolism is functioning."]

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

Key facts at a glance

LOINC
69771-4
Short code
Dicarboxyoleylcarn Amn-sCnc
Synonyms
Dicarboxyoleylcarn Amn-sCnc
Category
chemistry
Sample
fluid
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
2-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
Hemolysis max
300
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your doctor may recommend this test if you have symptoms like muscle weakness, fatigue, or unexplained problems with energy production. It’s also used in diagnosing conditions affecting fat metabolism, such as carnitine deficiency or mitochondrial disorders.

Common Conditions Monitored

This test is often checked in people with inherited metabolic disorders, heart conditions, or those on certain medications that affect carnitine levels. It may also be part of a broader evaluation for unexplained muscle or neurological symptoms.

Sample Collection and Preparation

A blood sample is drawn from a vein, usually in your arm. The blood is processed to separate serum or plasma, which is then sent for analysis. This test does not require fasting unless specified by your doctor.

What to Expect Before the Test

No special preparation is needed, but inform your doctor about any medications you’re taking, especially those affecting metabolism or blood tests. Avoid strenuous activity 24 hours before the test if instructed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Low levels of long-chain carnitine may suggest metabolic disorders, nutrient deficiencies, or conditions impairing fat metabolism. High levels could indicate liver disease, kidney problems, or certain genetic disorders. Results help guide treatment plans for conditions like carnitine palmitoyltransferase deficiency or mitochondrial disorders.

Short name

Long-Chain Carnitine

Frequently asked questions

What Does a Low or High Result Mean?
A low result might mean your body isn’t processing fats efficiently, which could affect energy levels or muscle function. A high result could signal underlying health issues like liver disease or kidney problems, but results alone don’t diagnose a condition—your doctor will interpret them with your full medical history.
How Often Should This Test Be Done?
The frequency depends on your health condition. If you have a known metabolic disorder, your doctor may order this test regularly. If it’s part of routine monitoring, they’ll let you know how often it’s needed.
Can Diet or Exercise Affect This Test?
Dietary changes, such as high-fat meals, can temporarily alter carnitine levels, so avoid extreme dietary shifts before testing. Exercise may also influence results, so follow your doctor’s instructions regarding activity levels before 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