Understanding Your Laboratory Test: What It Is, Why It Matters, and What to Expect
This test measures the level of 17-hydroxyprogesterone in your blood after a hormone stimulation test to help diagnose adrenal gland disorders.
{"17-Hydroxyprogesterone is a hormone made by the adrenal glands","The test helps diagnose congenital adrenal hyperplasia (CAH)","Blood samples are taken at multiple time points after a hormone injection","Elevated levels may indicate CAH or other adrenal disorders","Results help doctors determine appropriate treatment"}
Key facts at a glance
- LOINC
- 12717-5
- Short code
- 17-OHP 3rd post-ACTH
- Synonyms
- 17OHP sp3 p chal SerPl-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum Separator Tube (SST) or Plain Red Top Tube
- Units
- N/A
- Ref low
- 1
- Ref high
- 10
- Critical range
- — – 1000 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Chemiluminescent Immunoassay (CLIA) or Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
- CPT
- 83498
- SNOMED
- 31304003
- Specimen volume
- 1-2 mL serum minimum
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C): 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 50
- Lipemia max
- 100
- Icterus max
- 20
- TAT
- 24–72 hours
- Order
- routine
What is this test and what does it measure in my body?
The 17-Hydroxyprogesterone test measures the amount of a hormone called 17-hydroxyprogesterone (17-OHP) in your blood. This test is performed on the third blood sample collected after a stimulation test, also called a challenge test. During this test, you will receive an injection of a hormone (typically ACTH) that stimulates your adrenal glands to produce more hormones. Multiple blood samples are then taken at specific time intervals to see how your adrenal glands respond.
Why do I need this test, and what can the results tell my doctor about my health?
Your doctor may order this test if they suspect you or your child has a disorder of the adrenal glands, most commonly congenital adrenal hyperplasia (CAH). CAH is a genetic condition that affects the adrenal glands' ability to produce certain hormones. The test may also be used to monitor treatment effectiveness in patients already diagnosed with adrenal disorders.
How should I prepare for this test, including anything to avoid beforehand?
Follow your doctor's instructions about food and medication restrictions. You may need to fast for a certain period before the test. Inform your doctor about all medications you are taking, as some drugs can affect hormone levels. The test involves multiple blood draws over several hours, so plan accordingly and wear comfortable clothing.
What happens during the test, step by step, from start to finish?
A healthcare professional will first insert an intravenous (IV) line or draw blood from a vein in your arm. You will receive an injection of a stimulating hormone (ACTH). Blood samples will then be collected at specific intervals—typically at baseline (before the injection), and then at 30, 60, and 90 minutes after the injection. The third specimen refers to one of these follow-up blood draws.
Are there any risks, side effects, or complications I should be aware of?
The risks are minimal and similar to routine blood tests. You may experience slight pain or bruising at the injection site. Some people may feel lightheaded during or after the blood draw. The hormone injection may cause temporary flushing, increased heart rate, or mild discomfort, but these side effects usually subside quickly.
Reference range
Reference range varies by laboratory and methodology. Post-ACTH stimulation, 17-OHP typically remains below 10 ng/dL (0.3 nmol/L) in normal individuals. Values >15-20 ng/dL suggest possible 21-hydroxylase deficiency. Post-ACTH stimulated 17-OHP >1000 ng/dL is highly indicative of classic congenital adrenal hyperplasia.N/A
No fasting required. For ACTH stimulation test: baseline sample collected, then synthetic ACTH (cosyntropin) administered, followed by sequential blood draws at 30 and 60 minutes. Inform patient of multiple blood draws. Maintain adequate hydration.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is primarily used to diagnose and evaluate congenital adrenal hyperplasia (CAH), a group of genetic disorders affecting the adrenal glands. In CAH, the adrenal glands produce insufficient cortisol and often excess androgens. The 17-OHP level typically rises significantly after ACTH stimulation in individuals with CAH. The test can also help distinguish between different types of CAH and assess the severity of the condition. For patients already diagnosed with CAH, this test helps monitor the effectiveness of treatment and ensure proper hormone balance.
Frequently asked questions
What do high levels of 17-Hydroxyprogesterone mean?
What do normal levels mean?
How long does the entire test take?
Can this test be done on children?
Will I need to follow up after the test?
Sources
- 1
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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.
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 10, 2026. · Read our editorial policy