Growth Hormone (GH) Test
A growth hormone test measures GH, a hormone made by the pituitary gland. Growth hormone testing is nuanced, and its results are best planned and interpreted with a clinician's guidance.
About this test
Growth hormone, or GH, is produced by the pituitary gland, a small structure at the base of the brain. It plays a role in growth during childhood and in ongoing processes such as metabolism and tissue maintenance throughout life.
One reason growth hormone testing is considered nuanced is that GH does not stay steady through the day; it is released in bursts and shifts with factors such as sleep, activity, and timing. Because of this natural variability, a single measurement can be difficult to interpret on its own, and clinicians often plan GH testing carefully, sometimes alongside related markers.
Who might consider this test?
- It may come up when the pituitary is being explored or when growth-related signaling is part of a larger question.
- Given the nuance involved, GH is rarely approached as a casual standalone check
Test details
| Quest code | 521 |
|---|---|
| Methodology | Immunoassay |
| Sample type | 1 mL serum |
| Patient preparation | Fast as instructed, then rest for at least 30 minutes before your blood draw. |
| Collection | Quest patient service center |
Related tests and panels
Quest resources
Additional details
What growth hormone reflects
Growth hormone is central to growth in childhood and continues to take part in processes such as metabolism and tissue maintenance in adulthood. Measuring GH offers a glimpse of one part of the pituitary's activity. Because it interacts with other hormones and signals, it is generally understood as one thread within a broader hormonal picture rather than a self-contained answer.
Its release in pulses is a defining feature. Levels can differ substantially from one moment to the next, which is precisely why a clinician's guidance around timing and interpretation matters so much for this particular marker.
Why GH testing is clinician-guided
The natural variability of growth hormone means a single number rarely speaks for itself. Clinicians who evaluate GH often plan the testing thoughtfully and read the result alongside related markers and the full clinical context. Because of this, growth hormone is best approached as part of a clinician-directed evaluation, where the plan for testing and the reading of results are shaped by professional judgment rather than by a value alone.
Order online and a physician order is included — no doctor's visit and no insurance needed. Your sample is collected at a Quest Diagnostics patient service center.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does a growth hormone test measure?
It measures growth hormone, or GH, a hormone made by the pituitary gland that plays a role in growth and in ongoing processes such as metabolism and tissue maintenance.
Why is growth hormone testing described as nuanced?
GH is released in bursts and shifts with factors like sleep, activity, and timing, so a single measurement can be hard to interpret on its own. Clinicians often plan the testing carefully.
Should GH be tested on its own?
Growth hormone is generally a clinician-guided area rather than a casual standalone check. A clinician typically frames when it is measured, how it is timed, and what other markers accompany it.
How is the sample collected?
Through a routine blood draw at a patient service center. A phlebotomist takes a small sample from a vein in the arm and sends it to the laboratory.
Why does timing matter for this test?
Because GH levels can differ substantially from one moment to the next, following the ordering clinician's timing and preparation instructions is an especially important part of GH testing.
What does a Growth Hormone test cost without insurance?
$55. Celio Health's price is a flat cash price and insurance is never billed: the required physician's order is included.
Do I need to prepare for this test?
Fast as instructed, then rest for at least 30 minutes before your blood draw. This is the preparation Quest publishes for this test; if your clinician gives you different instructions, follow theirs.