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Serum or plasma concentration of free fatty acids (specifically medium-chain fatty acids, measured via immunoassay)

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

This test measures levels of medium-chain fatty acids in your blood, which can help assess metabolic health or detect certain genetic conditions.

Quick summary

["Medium-chain fatty acids play a role in energy production and metabolism; abnormal levels may signal metabolic disorders."]

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

Key facts at a glance

LOINC
11896-8
Short code
GA from BD.Jeanty84
Synonyms
GA from BD.Jeanty84
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
us-estimated-from-bd-jeanty
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 Ordered

Your healthcare provider may recommend this test if you have symptoms like unexplained fatigue, muscle weakness, or metabolic issues. It could also be part of a broader evaluation for inherited metabolic disorders or to monitor conditions like medium-chain acyl-CoA dehydrogenase (MCAD) deficiency.

What to Expect Before the Test

No special preparation is typically needed, but you may be asked to fast for a few hours before drawing blood. Avoid consuming fatty foods or supplements for that time if instructed.

What the Test Results Mean

Results show the concentration of specific medium-chain fatty acids in your blood. While reference ranges vary by lab, abnormal levels may indicate metabolic imbalances or genetic disorders requiring further medical evaluation.

Common Conditions Monitored

This test is often used to diagnose or monitor conditions like medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, a rare genetic disorder affecting fat metabolism. It may also be part of metabolic screening in newborns or individuals with unexplained metabolic symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Medium-chain fatty acid profile

Frequently asked questions

What does a high or low result mean?
High levels of medium-chain fatty acids may suggest impaired fat metabolism, potentially linked to genetic disorders or other metabolic dysfunctions. Low levels might indicate normal metabolism but could also be part of a broader metabolic evaluation if symptoms are present.
How often should I get this test?
The frequency depends on your medical condition and provider’s recommendations. If you have a known metabolic disorder, follow your doctor’s schedule for monitoring. Otherwise, this test may only be done as needed for specific evaluations.
Can I eat or drink anything before the test?
Check with your healthcare provider for specific instructions, but generally, avoid fatty foods or supplements for a few hours before your blood draw 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