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Carnitine (Long-Chain, Total) – Serum or Plasma Concentration

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 transport fatty acids into cells for energy production.

Quick summary

["Long-chain carnitine levels may indicate issues with fat metabolism or mitochondrial function."]

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

Key facts at a glance

LOINC
53542-7
Short code
Dodeicosanoylcarn Amn-sCnc
Synonyms
Dodeicosanoylcarn 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 metabolic problems—especially if you have conditions like mitochondrial disorders, fatty acid oxidation defects, or unexplained liver or kidney issues.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the draw if your doctor specifies it. Bring your test results and any medications you’re currently taking to your appointment.

What the Results Mean

Abnormally low levels might suggest a metabolic disorder affecting fat metabolism, while very high levels could indicate liver disease, muscle disorders, or certain genetic conditions. Your doctor will interpret results in the context of your overall health.

Common Conditions Linked to This Test

This test is often used to diagnose or monitor conditions like carnitine palmitoyltransferase (CPT) deficiencies, very long-chain acyl-CoA dehydrogenase (VLCAD) disorders, or other inherited metabolic diseases.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated or low carnitine levels can signal underlying metabolic dysfunctions that require specialized care, including dietary adjustments, enzyme replacement therapy, or genetic counseling. Early detection is critical for managing symptoms and preventing complications.

Short name

Total Long-Chain Carnitine

Frequently asked questions

What causes abnormal carnitine levels?
Abnormal results may stem from genetic disorders, liver or kidney disease, muscle disorders, or certain medications that affect metabolism. Conditions like diabetes, obesity, or heart disease can also influence carnitine metabolism.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your doctor will discuss findings with you during a follow-up visit.
Can diet affect carnitine test results?
Yes, dietary factors like high-fat foods or fasting status can influence carnitine levels. If your doctor orders this test, they may provide specific instructions to ensure accurate results.
  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