Serum or plasma concentration of free fatty acids (specifically long-chain fatty acids, measured via high-performance liquid chromatography)
This test measures the levels of certain long-chain fatty acids in your blood, which can help assess fat metabolism or identify abnormalities in how your body breaks down fats.
["Long-chain fatty acids play a role in energy production and cell function; abnormal levels may signal metabolic or genetic conditions."]
Key facts at a glance
- LOINC
- 11931-3
- Short code
- GA from HC.Hadlock82
- Synonyms
- GA from HC.Hadlock82
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 22
- Ref high
- 198
- Critical range
- — – 10000 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- us-estimated-from-hc-hadlock
- CPT
- 82553
- 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 of fatty acid metabolism disorders, such as unexplained muscle weakness, fatigue, or developmental delays in children. It may also be used to monitor conditions like mitochondrial disorders or to investigate unexplained high cholesterol or triglyceride levels.
What to Expect Before the Test
No special preparation is typically needed, but you may be asked to fast for 8–12 hours before the test if your blood is drawn in the morning. Avoid smoking or consuming alcohol for a few hours beforehand. Bring any medications you’re currently taking to your appointment.
What Happens During the Test
A healthcare professional will draw blood from a vein in your arm. The blood sample will be sent to a lab for analysis using high-performance liquid chromatography (HPLC), which separates and measures fatty acid levels with high precision.
What the Results Mean
Results will show the concentration of specific long-chain fatty acids in your blood. Abnormal patterns may indicate metabolic disorders, genetic conditions, or other health concerns that require further evaluation by a specialist.
Reference range
Adult males: 22-198 U/L; Females: 22-198 U/LN/A
No special preparation required. Inform provider of any chest pain or symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Free fatty acid profile
Frequently asked questions
What does a high or low level of free fatty acids indicate?
How often should I get this test?
Can I eat or drink anything before the test?
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 17, 2026. · Read our editorial policy