Insulin-Like Growth Factor 1 (IGF-1), Serum/Plasma — Concentration
Measures the amount of IGF-1 in blood. This test may help evaluate growth and disorders related to growth hormone.
["IGF-1 is a blood protein that reflects growth hormone activity and is often interpreted alongside other growth-related tests."]
Key facts at a glance
- LOINC
- 50501-6
- Short code
- Insulin sp1 SerPl-aCnc
- Synonyms
- Insulin sp1 SerPl-aCnc
- Category
- hormone
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 2.6
- Ref high
- 24.9
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 83525
- SNOMED
- 413618004
- 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
What is this test?
This test measures insulin-like growth factor 1 (IGF-1), also called somatomedin C, in serum or plasma. IGF-1 is a protein that helps tissues grow and is influenced by growth hormone.
Why might I need this test?
A clinician may order IGF-1 to investigate unusually tall or short stature, assess growth hormone activity, or help evaluate conditions involving excessive growth hormone. Results are often compared with other tests, such as growth hormone and IGF-binding protein measurements.
How is the test performed?
A blood sample is drawn from a vein and sent to a laboratory for measurement. Most laboratories use an immunoassay, although the specific method may vary.
How do I prepare for the test?
Fasting is usually not required, but follow any instructions from your clinician or laboratory. Tell the healthcare team if you are pregnant, have a recent illness, or take medicines that may affect growth hormone or IGF-1 levels.
Reference range
Fasting: 2.6-24.9 μIU/mLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated IGF-1 level may occur with excessive growth hormone activity, although it must be interpreted with other clinical and laboratory findings. A lower level may be associated with reduced growth hormone activity, nutritional factors, liver disease, or other conditions affecting growth, and age-specific interpretation is important.
Short name
IGF-1 test
Frequently asked questions
Is this the same as an insulin test?
Does IGF-1 require fasting?
Can one IGF-1 result confirm a growth hormone disorder?
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.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy