Sex Hormone Binding Globulin (SHBG)

The Sex Hormone Binding Globulin (SHBG) test measures a protein in the blood that carries hormones like testosterone, dihydrotestosterone, and estrogens. These hormones need to attach to this protein to move around in the body. The amount of this protein can go up or down because of different conditions or medicines.

For example, it increases when a person is pregnant, has an overactive thyroid, liver disease, or takes estrogen pills. It decreases if a person has conditions like low thyroid activity, Cushing’s syndrome, too much growth hormone, or is overweight.