Male hormone testing measures the level of testosterone in the blood. The blood sample is typically collected early in the morning. It is measured as total testosterone in combination with free testosterone and bioavailable testosterone. Most (over 98%) of the testosterone hormone is carried in the blood by two proteins, called sex hormone binding globulin (SHBG) and albumin. A very small amount (less than 2%) circulates in the blood as ‘free testosterone’. Free testosterone and the testosterone bound to albumin are called ‘bioavailable testosterone’. The protein-bound plus unbound (free) testosterone is measured by labs as total testosterone. Measurement of total testosterone alone does not always provide enough information. The level of SHBG, free and bioavailable testosterone should also be tested for more accurate diagnosis of a medical condition.