This test measures Free Testosterone—the active, usable form of the hormone in your body. While a 'Total Testosterone' test is common, this free level is what truly impacts your body's tissues, as it's not bound to other proteins. This test is essential for investigating symptoms of hormonal imbalance in both men and women, such as PCOS, unwanted hair growth, or low energy. A simple blood draw is required. This is the definitive, more advanced test to get a clear, accurate picture of your true hormonal status.