Serum Free and Total Testosterone
What We Test and What It Tells You
This profile assesses the levels of free and total testosterone. By knowing both levels, you can determine if your issues are due to reduced testosterone production or excessive testosterone binding.
Total-Testosterone, the dominant testicular androgen, is the amount produced by the testicles. 97 to 99% of this testosterone is bound in the blood primarily to SHBG (sex hormone binding globulin) and inactive. When SHBG levels are elevated due to a number of reasons including toxins and reduced carbohydrates, the amount of testosterone that is free will be reduced resulting in low testosterone symptoms even when total testosterone levels are considered within normal ranges.
Free-Testosterone, is the active testosterone available to signal the cell for energy, recovery and healthy function.