SHBG Blood Test
Reviewed
This test measures the level of sex hormone binding globulin (SHBG) in your blood. SHBG is a protein made mostly in your liver that attaches to sex hormones such as testosterone and estrogen. By binding to these hormones, SHBG helps control how much of them are active in your body. The test is most often used when you have signs of too much or too little testosterone, especially if a total testosterone test did not explain your symptoms. Your provider will usually interpret your SHBG result together with a total testosterone test to estimate how much free testosterone is available for your tissues to use.
Preparation and collection
No special preparations are needed. Tell your provider about all medicines, vitamins, and supplements you take, because certain hormone-containing medicines (such as birth control pills, estrogen therapy, or anabolic steroids) can affect SHBG levels. Do not stop any medicine unless your provider tells you to.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- An SHBG test alone cannot diagnose polycystic ovary syndrome (PCOS); it can help providers make a diagnosis when paired with other test results.
- Your provider will usually interpret SHBG results together with a total testosterone test to estimate free testosterone levels.
- Certain medicines containing hormones (such as birth control pills, estrogen therapy, or anabolic steroids) can affect SHBG levels.
What to do next
Your provider may order other tests to check if your hormones are in balance with each other. If you have questions about your results, talk with your provider.