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Very Long Chain Fatty Acids (VLCFA) Profile in Serum/Plasma

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

This test measures levels of very long-chain fatty acids, which are important for understanding metabolic health, particularly in conditions affecting fat metabolism.

Quick summary

["VLCFAs help diagnose and monitor rare genetic disorders linked to fat breakdown issues."]

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

Key facts at a glance

LOINC
12215-0
Short code
VLCFA SerPl-sCnc
Synonyms
VLCFA SerPl-sCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 Is Done

Your doctor may order this test if you have symptoms of a metabolic disorder, such as neurological problems, developmental delays, or recurrent episodes of illness. It’s also used to monitor treatment progress in patients with known fatty acid oxidation defects.

What to Expect Before the Test

No special preparation is needed. You may have blood drawn from a vein in your arm, similar to other blood tests. If you’re on a fasting diet, follow your doctor’s instructions.

What the Test Results Mean

Results show the concentration of specific very long-chain fatty acids in your blood. Abnormal levels may indicate metabolic disorders requiring further evaluation by a specialist.

Common Conditions Linked to This Test

High levels of VLCFAs are often seen in conditions like Zellweger syndrome, neonatal adrenoleukodystrophy, or other peroxisomal disorders. Low or normal levels may suggest no immediate concern but confirm a diagnosis if suspected.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

VLCFA Profile

Frequently asked questions

What questions might I have about this test?
This test is typically done to diagnose or monitor rare genetic disorders affecting fat metabolism. If you have symptoms like muscle weakness, developmental delays, or unexplained illness, ask your doctor if this test is appropriate for you.
How long will I need to wait for my results?
Results may take several days to a few weeks, depending on lab processing and follow-up needs. Your doctor will discuss findings with you during a follow-up visit.
Do I need to fast before this test?
Fasting may not be required, but follow your doctor’s instructions if they recommend it for your specific situation.
  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