The Free Testosterone test measures the amount of testosterone in the blood that is not bound to proteins and is biologically active. Free testosterone plays an important role in growth, puberty, muscle and bone development, mood, and reproductive health.
 This test is commonly used to help evaluate hormonal imbalances, delayed or early puberty, menstrual irregularities, infertility, or symptoms such as fatigue, acne, excessive hair growth, or low libido.
 The test is performed using a blood sample and analyzed through a hormone assay for accurate measurement.