17ohp2hpchalserplmcnc
A blood test measuring 17-hydroxyprogesterone levels 2 hours after ACTH hormone stimulation to evaluate adrenal gland function.
{"Measures how your adrenal glands respond to hormonal stimulation","Helps diagnose adrenal disorders like congenital adrenal hyperplasia (CAH)","Involves a blood draw before and 2 hours after receiving ACTH hormone","Elevated results may indicate adrenal enzyme deficiencies","Results help doctors plan appropriate treatment"}
Key facts at a glance
- LOINC
- 56617-4
- Short code
- 17-OHP-STIM
- Synonyms
- 17OHP 2h p chal SerPl-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or plain red top tube
- Units
- N/A
- Ref low
- 100
- Ref high
- 300
- Critical range
- — – 1000 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Chemiluminescent Immunoassay (CLIA) or Enzyme-Linked Immunosorbent Assay (ELISA)
- CPT
- 82533
- SNOMED
- 31323002
- Specimen volume
- 1.0-2.0 mL serum minimum
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 50
- Lipemia max
- 300
- Icterus max
- 20
- TAT
- 24–72 hours
- Order
- routine
What is this test?
The 17-Hydroxyprogesterone (17-OHP) challenge test measures the level of 17-hydroxyprogesterone in your blood 2 hours after receiving an injection of ACTH (adrenocorticotropic hormone). ACTH is a hormone that stimulates your adrenal glands to produce other hormones, including cortisol and androgens. This test evaluates how well your adrenal glands are functioning.
Why is this test performed?
This test is primarily used to diagnose and monitor congenital adrenal hyperplasia (CAH), a genetic disorder affecting the adrenal glands' ability to produce cortisol. It may also be used to evaluate adrenal insufficiency and distinguish between different types of adrenal disorders. Your doctor may order this test if you or your child show symptoms such as early puberty, irregular periods, excessive hair growth, or ambiguous genitalia.
How is the test done?
The test requires two blood samples. First, a baseline blood sample is taken to measure your initial 17-OHP level. Then, you will receive an injection of synthetic ACTH (cosyntropin). After exactly 2 hours, another blood sample is collected. The time interval is important because it allows the ACTH to stimulate your adrenal glands and peak hormone levels to be measured.
How to prepare for the test?
Your doctor will provide specific instructions. Generally, you may need to fast (not eat or drink except water) for 8-12 hours before the test. Certain medications, especially corticosteroids and hormone treatments, may affect results and should be discussed with your doctor. Inform your healthcare provider about all medications, supplements, and herbal remedies you are taking.
What do the results mean?
Normal results vary by age and gender. Elevated 17-OHP levels after ACTH stimulation typically indicate congenital adrenal hyperplasia or other adrenal enzyme deficiencies. Your doctor will interpret your results alongside your symptoms and other test findings. A definitive diagnosis may require additional testing or genetic testing.
Reference range
2 hours post-ACTH stimulation: Normal response <100 ng/dL (<3.03 nmol/L). Borderline: 100-300 ng/dL (3.03-9.09 nmol/L). Elevated (>300 ng/dL or >9.09 nmol/L) suggests 21-hydroxylase deficiency. Reference ranges may vary by laboratory methodology.N/A
Collect sample in the morning (typically 8-10 AM). Patient should be at rest. No fasting required, but avoid strenuous exercise prior to collection. Inform physician of current medications, especially glucocorticoids, hormonal contraceptives, or adrenal hormone supplements that may affect results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Is the ACTH injection safe?
How long does the entire test take?
Can children have this test?
What happens if I cannot return for the second blood draw?
Sources
- 1
- 2
- 3
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.
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 15, 2026. · Read our editorial policy