Serum or plasma concentration of free fatty acids (non-esterified fatty acids)
This test measures the amount of free fatty acids in your blood, which are important energy sources for your body.
["Free fatty acids help your body use energy efficiently and support healthy metabolism."]
Key facts at a glance
- LOINC
- 78374-6
- Short code
- D farinae (nDer f) 2 IgE Qn
- Synonyms
- D farinae (nDer f) 2 IgE Qn
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 86430
- 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 check free fatty acids if you have symptoms like unusual fatigue, rapid heartbeat, or unexplained weight changes. It can also be part of tests for metabolic disorders, diabetes, or thyroid conditions.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to fast for a few hours before the blood draw. Wear a loose shirt for easy access to your arm.
What Happens During the Test
A healthcare professional will insert a small needle into your vein to draw blood. You may feel a slight pinch, but it usually doesn’t cause discomfort. The blood is then sent to a lab for analysis.
What the Results Mean
Results help assess how well your body is using fats for energy. High levels might indicate conditions like diabetes or thyroid issues, while very low levels could suggest malnutrition or certain metabolic disorders.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Free Fatty Acids (FFA)
Frequently asked questions
What questions might you have about this test?
Will I need to do anything special after the test?
Could fasting affect my results?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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