Sex hormone-binding globulin (SHBG) produced by the liver helps to transport biologically inactive forms of hormones such as testosterone, estradiol, and dihydrotestosterone into the bloodstream. Changes in its levels may have an effect on the amount of hormone available to the body. SHBG test is used for the evaluation of androgen deficiency or excess. Increased SHBG may be associated with liver disease, hyperthyroidism, hormone replacement therapy, oral contraceptives, and fertility issue. Deficiency is observed in metabolic syndrome, polycystic ovary syndrome, hypothyroidism, and Cushing syndrome.