Testosterone Total and Free with Sex Hormone Binding Globulin (SHBG) Test

This test measures testosterone levels in saliva, a non-invasive alternative to blood testing. Testosterone is the primary male sex hormone and is also produced in smaller amounts in women. It regulates muscle mass, bone density, energy, mood, and sexual function. Abnormally high or low testosterone can indicate hormone imbalances affecting metabolism, mood, and physical performance. Salivary testosterone reflects the bioavailable hormone level and may be useful for tracking changes over time.

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.

Free testosterone is the biologically active form of testosterone that is not bound to carrier proteins in the blood. While total testosterone measures all forms, free testosterone better reflects the hormone available for body tissues. This test helps evaluate hormonal function in both men and women. Low free testosterone in men may cause fatigue, reduced libido, or muscle loss, while elevated levels in women may indicate polycystic ovary syndrome (PCOS) or other hormonal disorders. This test provides detailed hormonal assessment.

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.