17ohp20mpatchserplscnc

Published: August 9, 2026Updated: August 10, 2026

A blood test that measures 17-hydroxyprogesterone levels before and after ACTH hormone injection to help diagnose adrenal gland disorders.

Quick summary

{"Measures how your adrenal glands respond to ACTH hormone stimulation","Helps diagnose congenital adrenal hyperplasia (CAH) and adrenal insufficiency","Involves two blood draws: one before and one 20-30 minutes after ACTH injection","Elevated 17-OHP levels after stimulation suggest CAH","The test is typically performed in the morning after overnight fasting"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 10, 2026Editorial policy

Key facts at a glance

LOINC: 74350-0
Short code: 17-OHP ACTH stim
Synonyms: 17OHP 20M p ATCH SerPl-sCnc
Category: chemistry
Sample: serum
Container: Serum separator tube (SST/gold top) or plain red top tube
Units: N/A
Ref low: 3
Ref high: 10
Critical range: — – 30 N/A
Fasting: false
Population: adult
Sex: all
Age range: ≥ 0 years
Method: Immunoassay (Chemiluminescent or Enzyme-linked)
CPT: 83498
SNOMED: 313294004
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: 300
Icterus max: 20
TAT: 24–72 hours
Order: routine

What is this test?

The 17-Hydroxyprogesterone (17-OHP) After ACTH Stimulation Test is a specialized blood test that measures the level of 17-hydroxyprogesterone in your blood before and after an injection of adrenocorticotropic hormone (ACTH). ACTH is a hormone produced by the pituitary gland that tells your adrenal glands to produce cortisol and other steroid hormones. By measuring 17-OHP levels before and after ACTH stimulation, doctors can evaluate how well your adrenal glands are functioning and detect certain disorders.

How is the test performed?

The test involves several steps: First, a healthcare professional will insert an intravenous (IV) line or draw blood from your arm to collect a baseline sample (before ACTH). Then, synthetic ACTH (cosyntropin) is injected into your muscle or vein. After 20-30 minutes, another blood sample is collected. The entire procedure usually takes about an hour. You may be asked to fast overnight and avoid certain medications before the test, as instructed by your healthcare provider.

Why might I need this test?

Your doctor may order this test if you or your child have symptoms suggesting a adrenal gland problem, such as early puberty, irregular periods, excessive hair growth, or signs of hormonal imbalance. It is commonly used to diagnose and monitor congenital adrenal hyperplasia (CAH), a genetic condition affecting adrenal hormone production. The test can also help distinguish between adrenal and gonadal sources of hormonal abnormalities and assess adrenal insufficiency.

What do the results mean?

Results are interpreted by comparing the baseline (before ACTH) and stimulated (after ACTH) 17-OHP levels. Significantly elevated 17-OHP levels after ACTH stimulation typically indicate congenital adrenal hyperplasia (CAH). Mild to moderate elevations may suggest other forms of adrenal dysfunction. Normal responses indicate healthy adrenal gland function. Your healthcare provider will explain your specific results in the context of your symptoms, medical history, and other test findings.

Reference range

Response to ACTH stimulation: 17-OHP typically rises 2-5 fold above baseline at 20 minutes post-ACTH injection. Peak response expected >10 nmol/L in normal adrenal function. Baseline 17-OHP: 0.6-2.0 nmol/L (adults). Post-stimulation: 3-10 nmol/L (normal response). Significantly elevated levels (>15 nmol/L) suggest congenital adrenal hyperplasia or adrenal neoplasia.N/A

Specimen: serum

No fasting required. For ACTH stimulation test: baseline sample collected, then synthetic ACTH (cosyntropin) administered intravenously (250 mcg), second sample collected exactly 20 minutes post-dose. Inform patient of test duration (~30 minutes). Continue medications as prescribed unless instructed otherwise by physician.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings3

Frequently asked questions

Is the ACTH stimulation test safe?

The test is generally safe for most patients. The ACTH injection (cosyntropin) is a synthetic version of a natural hormone and is well-tolerated. Some people may experience mild side effects such as facial flushing, headache, or dizziness. Serious allergic reactions are rare but possible. Pregnant women should inform their doctor as the test may not be recommended during pregnancy.

Do I need to prepare for the test?

Yes, preparation is important. You will typically be asked to fast overnight (8-12 hours) before the test. Certain medications, especially corticosteroids, hormonal treatments, and some supplements, may interfere with results and should be discussed with your doctor. Women should inform their doctor about their menstrual cycle, as hormone levels can vary throughout the cycle. Follow all specific instructions provided by your healthcare team.

How long does it take to get results?

Results are usually available within a few days to a week, depending on the laboratory. Your healthcare provider will contact you with results or discuss them at your follow-up appointment. Because this is a specialized test, some laboratories may take longer to process the samples.

What happens if my results are abnormal?

Abnormal results do not always mean you have a serious condition. Your doctor will consider your symptoms, medical history, and other test results to make a diagnosis. If CAH or adrenal insufficiency is suspected, you may be referred to an endocrinologist for further evaluation and treatment. Treatment for CAH typically involves corticosteroid replacement therapy to manage symptoms and prevent complications.

Can children undergo this test?

Yes, the test is commonly performed in children, especially infants and young children suspected of having classic CAH. The procedure is similar for children, though the ACTH dose may be adjusted based on weight. A pediatric endocrinologist typically oversees testing in children. Parents can help by explaining the procedure to their child in age-appropriate terms to reduce anxiety.

Sources

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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

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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