The Free Testosterone test measures the levels of unbound (free) testosterone in the serum, which is the active form of the hormone that can directly affect tissues. Testosterone is a steroid hormone primarily produced by the testes in males, but it is also produced in smaller amounts by the adrenal glands in both males and females, and by the ovaries in females.
This test is used to evaluate testosterone-related conditions, such as low testosterone (in males) or excessive androgen production (in females), and to help diagnose conditions like PCOS (Polycystic Ovary Syndrome) or hypogonadism.