Sex Hormone Binding Globulin (SHBG) Test
An SHBG test measures sex hormone binding globulin, a protein that carries sex hormones through the blood. Clinicians use it to help interpret how much of those hormones is available to the body.
About this test
Sex hormone binding globulin, or SHBG, is a protein made mainly in the liver that binds to sex hormones such as testosterone and estradiol and carries them through the bloodstream. Hormones attached to SHBG are held in reserve, while the unbound portion is the part most readily available to tissues. Because SHBG affects that balance between bound and free hormone, it is a marker clinicians often use to help make sense of sex-hormone results.
The SHBG test is performed with a routine blood draw at a patient service center, where a phlebotomist collects a sample from a vein in the arm and sends it to the laboratory. SHBG can be influenced by a range of factors, so a clinician typically reviews it in the context of the sex-hormone markers it accompanies. People follow any preparation instructions their ordering clinician provides, since individual situations differ.
Who commonly orders it
People who order an SHBG test are usually not looking at it for its own sake but to help interpret other sex hormones. When a testosterone or estradiol result and a person's situation seem to point in different directions, SHBG can help explain how much of the hormone is actually available to tissues. It is frequently chosen as a companion marker within a broader hormonal review rather than as a standalone test.
What SHBG does
SHBG acts like a transport and storage system for sex hormones. When a hormone is bound to SHBG, it is being carried and held rather than acting on tissues; the unbound portion is the part more freely available. By measuring SHBG, a clinician gains insight into how a person's sex hormones may be divided between the bound and free states.
This is why SHBG rarely tells a useful story on its own. Its value comes from the context it adds to other hormone results, helping a clinician move from how much hormone is present toward how much may be available to the body.
How it helps interpret other hormones
Because SHBG shapes the balance between bound and free hormone, it is commonly read alongside markers such as testosterone or estradiol. Two people with similar total hormone results can have different amounts of available hormone if their SHBG differs, and that is exactly the kind of nuance SHBG helps a clinician see. Interpreted together, these markers give a fuller sense of hormonal activity than any one of them alone.
What to expect at your visit
No appointment is needed. People can visit a patient service center during open hours, and the draw takes only a few minutes, with a phlebotomist collecting a small sample from a vein in the arm. Once the laboratory completes its analysis, results are posted to the account, where they can be reviewed and shared with a clinician who interprets them alongside the hormones they accompany.
Your results
Results will be emailed securely to you as a PDF.
One-time price · physician order included · no insurance needed
Prefer a fuller panel?
A curated bundle groups this test with the markers clinicians most often review alongside it — often better value than single tests.
Frequently asked questions
What does an SHBG test measure?+–
It measures sex hormone binding globulin, a protein that carries sex hormones such as testosterone and estradiol through the blood. It helps a clinician interpret how much of those hormones is available to tissues.
Why is SHBG usually measured with other hormones?+–
SHBG shapes the balance between bound and free hormone, so its value comes from the context it adds to markers like testosterone or estradiol rather than from a result on its own.
What does it mean that a hormone is bound to SHBG?+–
A hormone attached to SHBG is being carried and held in reserve rather than acting on tissues, while the unbound portion is the part more readily available to the body.
How is the sample collected?+–
Through a routine blood draw at a patient service center. A phlebotomist takes a small sample from a vein in the arm and sends it to the laboratory.
Can two people with similar hormone results differ in available hormone?+–
Yes. If their SHBG differs, the amount of hormone available to tissues can differ even when the total looks similar, which is one reason a clinician considers SHBG.
How much does the Sex Hormone Binding Globulin test cost?+–
The cash price at Celio Health is $79. That covers the physician's order and the blood draw at a Quest patient service center — no insurance is needed and there's no separate doctor's visit to pay for.