SHBG Blood Test Test
The SHBG blood test measures a protein that binds to sex hormones like testosterone and estrogen, helping control how much of these hormones are active in your body. It is often used to help diagnose hormonal disorders or understand symptoms of too much or too little testosterone.
What this test measures
An SHBG blood test measures the level of a protein called sex hormone binding globulin (SHBG) in a sample of your blood. SHBG is made mostly in your liver. It binds to sex hormones such as testosterone and estrogen and helps control how much of these hormones are active in your body.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
If your SHBG levels are too high, it likely means that less of your total testosterone is available for your tissues to use. High levels of SHBG may be related to liver disease, hyperthyroidism (overactive thyroid), certain eating disorders, use of estrogen-containing medicines, or decreased production of sex hormones in males.
Lower-than-normal results
If your SHBG levels are too low, it means that more of your total testosterone is likely free and available for your body to use. Low levels of SHBG may be related to hypothyroidism (underactive thyroid), type 2 diabetes or insulin resistance, obesity, overuse of steroid medicines and/or anabolic steroids, Cushing's syndrome, or polycystic ovary syndrome (PCOS) in females.
Frequently asked questions
What is an SHBG blood test?
An SHBG blood test measures the level of sex hormone binding globulin (SHBG) in your blood. SHBG is a protein made mostly in your liver that binds to sex hormones like testosterone and estrogen.
Why is an SHBG test done?
It is often done if you have symptoms of too much or too little testosterone. It can help diagnose hormonal disorders like PCOS, monitor treatments, or help diagnose early puberty in children.
How is an SHBG test different from a total testosterone test?
A total testosterone test measures both free and bound testosterone but cannot tell them apart. An SHBG test helps estimate how much free testosterone is available for your body to use.
What does a low SHBG level mean?
Low SHBG means more of your total testosterone is likely free and available. It may be related to conditions like hypothyroidism, type 2 diabetes, obesity, or PCOS.
What does a high SHBG level mean?
High SHBG means less of your total testosterone is available for tissues. It may be related to liver disease, hyperthyroidism, eating disorders, or use of estrogen-containing medicines.
Related lab tests
Sources
- MedlinePlus: SHBG Blood Test — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.