Sex Hormone Binding Globulin (SHBG) is a glycoprotein, synthesized in liver. SHBG levels are commonly measured as a supplement to total testosterone determinations. Decreased SHBG levels are often found in Hirsutism, Acne vulgaris and the polycystic ovarian disorder. An SHBG test is most often used to find out how much testosterone is going to the bodys tissues. Testosterone levels can be measured in a separate test called total testosterone. This test shows how much testosterone is in the body, but not how much is being used by the body. Sometimes a total testosterone test is enough to make a diagnosis. But some people have symptoms of too much or too little of the hormone that the total testosterone test results cant explain. In these cases, an SHBG test may be ordered to provide more information about how much testosterone is available to the body.