SHBG

SHBG (sex hormone binding globulin) is a protein made mostly in your liver. It binds (attaches) to sex hormones in your blood. SHBG helps control the amount of sex hormones that are actively working in your body. When the SHBG protein binds to sex hormones, your tissues can’t use those hormones. Your tissues can only use sex hormones that are “free,” which means they aren’t attached to proteins, such as SHBG. An SHBG test is usually done if you have signs and/or symptoms of having too much or too little of the sex hormone testosterone. Testosterone is known as a “male” sex hormone, but females have testosterone in smaller amounts. In adult males, testosterone controls sex drive, maintains muscle mass, and helps make sperm. In adult females, testosterone is important for healthy organs and the growth of bones and muscles. Measuring SHBG levels provides information about how much of your testosterone is active in the tissues of your body.