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Insulin-like Growth Factor I (IGF-I) Serum/Plasma Concentration

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

This test measures the amount of IGF-I, a protein produced by the liver in response to growth hormone, which plays a key role in growth, cell repair, and metabolism.

Quick summary

["IGF-I helps regulate growth and development, and levels can reflect overall health and hormonal balance."]

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

Key facts at a glance

LOINC
35213-8
Short code
IGF-I SerPl-msCnc
Synonyms
IGF-I SerPl-msCnc
Category
hormone
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

What Is IGF-I Used For?

IGF-I is primarily measured to assess growth hormone function, monitor conditions affecting growth (like short stature or growth hormone deficiency), and evaluate metabolic health. It may also be checked in cases of suspected pituitary disorders or metabolic syndromes.

When Might You Need This Test?

Your doctor might order an IGF-I test if you have symptoms of growth hormone issues (such as slow growth in children, muscle weakness, or fatigue), suspected pituitary problems, or if you’re undergoing treatment for conditions like diabetes or metabolic disorders.

How Is the Test Performed?

A blood sample is drawn from a vein, usually in your arm. The sample is sent to a lab where it’s analyzed to measure IGF-I concentration using an immunoassay method.

What Do Results Mean?

Results provide a quantitative measure of IGF-I levels, though exact reference ranges vary by lab. Abnormal results may signal growth hormone imbalances, metabolic disorders, or other health concerns that require further evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IGF-I Level

Frequently asked questions

Why was this test ordered?
Your doctor may have ordered this test to check for growth hormone deficiencies, evaluate metabolic health, or monitor conditions like diabetes or pituitary disorders. Low or high IGF-I levels may point to hormonal imbalances or other health issues that need attention.
What does a low IGF-I level mean?
Low IGF-I levels may suggest growth hormone deficiency, poor nutrient absorption, or certain metabolic disorders. Your doctor will discuss next steps based on your symptoms and test results.
What does a high IGF-I level mean?
High IGF-I levels can occur with overproduction of growth hormone, certain liver diseases, or metabolic conditions. Further testing may be needed to determine the cause and guide treatment.
  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