Growth Hormone (GH)
A blood test that measures growth hormone levels to assess pituitary function and diagnose growth hormone deficiency or excess.
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Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
What this test measures
Growth hormone (GH), also called somatotropin, is produced by the pituitary gland and drives growth and development in children by stimulating the liver to produce insulin-like growth factor 1 (IGF-1). After the growth plates in bones fuse and adult height is reached, GH continues to play important roles in maintaining body composition, supporting muscle and bone integrity, regulating metabolism, and helping manage blood glucose levels.
The pituitary gland does not release GH at a steady rate. Instead, it secretes the hormone in short bursts throughout the day and night, with the largest pulses typically occurring during deep sleep. This pulsatile secretion pattern means that a single random blood draw may catch a peak, a trough, or anything in between, making isolated GH measurements difficult to interpret on their own. For this reason, GH testing is often paired with IGF-1 measurement, which remains far more stable throughout the day and provides a reliable reflection of average GH activity over time. In some cases, specialized stimulation or suppression tests are used to evaluate GH function more definitively.
Who should consider this test
You might consider this test if you are experiencing any of the following:
- Individuals experiencing unexplained fatigue, decreased muscle mass, or changes in body composition, as these symptoms may be associated with growth hormone deficiency in adults.
- Those with concerns about pituitary function, particularly individuals who have had brain surgery, radiation therapy, or head trauma that could affect the pituitary gland.
- Patients with a family history of pituitary disorders or those who have been diagnosed with other hormone deficiencies that may indicate broader pituitary dysfunction.
- Individuals being evaluated for potential acromegaly or gigantism, conditions associated with excessive growth hormone production that can cause abnormal growth patterns.
- Adults with unexplained changes in bone strength, cardiovascular risk factors, or cholesterol levels, as growth hormone plays a role in bone metabolism and cardiovascular health.
What to expect
Preparation
Fasting for 8-12 hours before the test is recommended. Complete rest for at least 30 minutes before blood collection is required to minimize stress-related hormone fluctuations. Inform the healthcare provider about any medications, especially biotin supplements, which should be discontinued 72 hours before testing.
Sample Type
A simple blood draw from a vein in the arm, similar to other routine blood tests. The sample will be collected in a specialized tube and processed in the laboratory.
Collection
The blood collection takes only a few minutes and is performed by trained phlebotomists at the lab location. No special equipment or extended monitoring is required for this basic GH measurement.
Turnaround
Results are typically available within 1-3 business days after the sample reaches the laboratory.
Understanding your results
Because GH is released in pulses, a single random measurement can vary widely and is rarely sufficient on its own to diagnose a growth hormone disorder. A low reading may simply reflect a trough between secretion bursts rather than true deficiency. Healthcare providers interpret GH results alongside IGF-1 levels, clinical symptoms, growth data (in children), and sometimes the results of formal stimulation or suppression tests to arrive at an accurate assessment of pituitary function and growth hormone status.
| Population | Reference Range | Notes |
|---|---|---|
| Adult Males | 0.4-10 ng/mL (18-44 pmol/L) | Normal random levels for healthy adult men |
| Adult Females | 1-14 ng/mL (44-616 pmol/L) | Normal random levels for healthy adult women |
| Children | 10-50 ng/mL (440-2200 pmol/L) | Normal random levels for children and adolescents |
Reference ranges may vary by laboratory and individual factors. Results should be interpreted by a healthcare provider in the context of your overall health.
What does a “Low” result mean?
Low growth hormone levels may be associated with growth hormone deficiency, which can cause slow growth rates in children and symptoms such as fatigue, decreased muscle mass, changes in cholesterol levels, and reduced bone strength in adults. In children, insufficient GH secretion can lead to impaired linear growth and may cause delayed sexual maturity in adolescents. However, because growth hormone is released in pulses, low random levels may also represent normal physiological patterns and require confirmation through stimulation testing.
What does a “High” result mean?
Elevated growth hormone levels may indicate the possibility of gigantism in children or acromegaly in adults, conditions often caused by pituitary adenomas. In children, this can lead to excessive growth and very tall stature, while in adults it may cause enlargement of hands, feet, and facial features. Elevated levels may also be found in certain nutritional disturbances such as anorexia, starvation, or chronic liver or kidney disease. Confirmation of growth hormone excess typically requires additional suppression testing.
Privacy & confidentiality
Your growth hormone test results are completely confidential and protected under HIPAA regulations. Results will not be shared with your personal physician unless you specifically request it, will not be added to your medical records, and will not appear on insurance explanation of benefits. Access your secure results online with complete privacy.
Frequently asked questions
Related tests
IGF-1 (Insulin-Like Growth Factor-1)
Often ordered alongside growth hormone testing as it provides a more stable measure of growth hormone activity
View TestCortisol
Part of comprehensive pituitary function assessment, as cortisol is another key hormone produced by the pituitary-adrenal axis
View TestThyroid Panel (Basic)
Thyroid function can affect growth and metabolism and may be evaluated alongside growth hormone in comprehensive endocrine assessment
View TestProlactin
Another pituitary hormone that may be tested when evaluating overall pituitary gland function
View TestRelated conditions
Last reviewed: April 2026
CPT Code: 83003
This test may not be available in: NY, NJ, RI
This page is for informational purposes only and does not constitute medical advice. Always consult with a healthcare provider regarding any health concerns. LevelPanel does not diagnose, treat, or prescribe.
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LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
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