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Butyrylcarnitine (C4-Carnitine) in Serum/Plasma

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

This test measures butyrylcarnitine, a form of carnitine involved in fat metabolism, found in your blood.

Quick summary

["Butyrylcarnitine helps assess how well your body processes fats and detects potential metabolic disorders."]

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

Key facts at a glance

LOINC
50148-6
Short code
G-OH-Butyr Amn-sCnc
Synonyms
G-OH-Butyr 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 healthcare provider may recommend this test if you have symptoms like muscle weakness, fatigue, or unexplained health issues that could be linked to carnitine metabolism problems. It’s also used in diagnosing conditions like mitochondrial disorders, inherited metabolic diseases, or carnitine deficiency.

What to Expect Before the Test

No special preparation is usually needed. You may have a small needle inserted into your arm to draw blood. If you’re on a fasting diet, follow your provider’s instructions to ensure accurate results.

What the Results Mean

Elevated levels might suggest an issue with fat metabolism or certain genetic disorders. Lower levels could indicate a deficiency or problems with how your body transports fatty acids. Your provider will discuss these findings with you.

Common Conditions Linked to This Test

This test can help identify conditions like medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, carnitine palmitoyltransferase II (CPT-II) deficiency, or other inherited metabolic disorders that affect energy production.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Carnitine Metabolite

Frequently asked questions

What causes elevated butyrylcarnitine levels?
Elevated butyrylcarnitine can occur due to genetic metabolic disorders, severe illness, or conditions affecting fat metabolism. It may also appear in people with uncontrolled diabetes or heart conditions.
How often should this test be repeated?
Your provider will determine how often to repeat this test based on your symptoms, medical history, and treatment plan. Follow-up may be needed if initial results suggest a metabolic issue.
Can diet affect butyrylcarnitine levels?
Yes, diet can influence carnitine levels. High-fat diets or certain supplements may temporarily alter results. Always inform your provider about any dietary changes before testing.
  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