Sex Hormone-Binding Globulin (SHBG)

This test measures free and weakly bound testosterone adjusted for sex hormone binding globulin (SHBG) levels, providing a more accurate picture of biologically active testosterone than total testosterone alone. SHBG binds testosterone in the blood, reducing its availability to tissues. By accounting for SHBG, this calculation better reflects the testosterone your body can actually use. This is particularly useful for evaluating symptoms of hormone imbalance in both men and women, including fatigue, mood changes, sexual function, and muscle mass.

Sex hormone binding globulin (SHBG) is a protein produced by the liver that binds and transports sex hormones (testosterone and estrogen) throughout your body. SHBG levels affect how much hormone is freely available for your body to use. Low SHBG is associated with insulin resistance, metabolic syndrome, and increased cardiovascular risk, while elevated levels may indicate liver disease or certain medications. This test helps evaluate hormonal balance and metabolic health.