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Growth Hormone (GH) by Immunoassay (Serum)

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

This test measures the amount of growth hormone, a protein hormone produced by your pituitary gland, in your blood. It helps assess growth, metabolism, and potential hormone imbalances.

Quick summary

["Growth hormone levels can affect growth in children, muscle and bone health, and metabolism in adults."]

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

Key facts at a glance

LOINC
76516-4
Short code
GA--@ birth
Synonyms
GA--@ birth
Category
chemistry
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

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like slow growth in children, unusual weight changes, muscle weakness, or conditions like gigantism, acromegaly, or growth hormone deficiency.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8 hours before the test. Bring any medications you’re currently taking to your appointment.

What the Test Involves

A blood sample will be drawn from a vein in your arm. You may feel a slight pinch, but it usually takes only a few minutes. The sample is sent to a lab for analysis using an immunoassay method to detect growth hormone levels.

What the Results Mean

Results are compared to standard reference ranges for your age and gender. Abnormal results may indicate conditions like pituitary tumors, diabetes, or other metabolic disorders.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Growth Hormone (Serum)

Frequently asked questions

What causes growth hormone levels to be tested?
Growth hormone testing is often done to diagnose conditions like growth hormone deficiency in children, or to check for overproduction (such as acromegaly) in adults. It may also be used to monitor treatment responses for hormone-related disorders.
How long does it take to get the results?
Results are typically available within 1 to 3 business days, depending on your lab’s processing time. Your healthcare provider will discuss the results with you during your follow-up visit.
Can I eat or drink before the test?
You may have to fast for 8 hours before the test, but you can drink water unless instructed otherwise. Always follow your healthcare provider’s specific instructions.
  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