Platform
Company
Endocrine & Reproductive
Review status
Currently under review
Pending specialist review and validation.
17 Alpha-hydroxy progesterone (17-OHP) is a steroid hormone made mainly by the adrenal glands, with smaller amounts from the ovaries or testes. It is a building block in the pathways that produce cortisol and androgens. Because it sits in the middle of these pathways, changes in enzyme activity can cause 17-OHP to rise or fall.
This blood test measures the amount of 17-OHP circulating in your body. It is commonly used to evaluate adrenal function, to screen or investigate congenital adrenal hyperplasia, and to help explain symptoms related to androgen excess. It may also be used to monitor treatment in people with known adrenal disorders.
Doctors use 17-OHP testing to look for conditions where cortisol production is impaired and steroid precursors build up, such as congenital adrenal hyperplasia due to 21-hydroxylase deficiency. In newborns, timely testing helps identify serious forms that can affect salt balance and overall health. In children and adults, it can help explain early pubertal changes, acne, or excess hair growth.
In women with irregular periods, infertility, or signs of androgen excess, 17-OHP can help distinguish among possible causes. The test also guides treatment in those already diagnosed, helping to balance therapy and avoid under- or overtreatment. Your clinician will interpret the result in the context of your age, symptoms, and other labs.
Results are interpreted alongside your age, time of day the sample was drawn, menstrual cycle phase if applicable, and overall health. Laboratories use different methods, so comparing results over time is most reliable when testing is done the same way and at similar times of day. Your clinician may recommend repeating the test or using a specialized stimulation test to clarify borderline or unexpected results.
A higher level may prompt additional evaluation for adrenal enzyme deficiencies, consideration of genetic testing, or assessment for other adrenal or ovarian conditions. A lower level during treatment may indicate adequate control, although levels that are too low can suggest overtreatment. If your result does not match your symptoms, your clinician may adjust timing, review medications, or order complementary hormone tests before deciding on next steps.
Reference intervals vary by laboratory, analyzer, methodology, population, and units. The ranges shown here are for education only. Always interpret your results against the reference interval printed on your own lab report.
17-OHP follows a daily pattern with higher levels in the morning. Drawing blood early in the day and using consistent timing improves interpretation.
In people who menstruate, luteal phase levels can be higher. Many clinicians prefer sampling in the early follicular phase for consistency.
Acute illness, significant stress, or recent hospitalization can alter adrenal hormone production and transiently affect 17-OHP results.
Glucocorticoids lower 17-OHP, while adrenal stimulation (for example, ACTH tests) can raise it. Oral contraceptives and antiandrogens may also influence results.
Premature or ill newborns can have higher baseline values. Repeat testing after stabilization is often needed to avoid false positives.
Physiologic changes in pregnancy can increase steroid precursors. If you are pregnant, your clinician will interpret values within that context.
Different methods and reference materials can give slightly different values. Using the same lab and method supports consistent follow-up.
Chronic liver or kidney conditions can modify hormone metabolism and binding, which may influence measured 17-OHP levels.
References