Testosterone, Bioavailable Unit Converter

Bioavailable testosterone is the portion of testosterone in your blood that is readily available for your body to use. It includes both free testosterone (unbound, about 2-3%) and testosterone loosely bound to albumin (about 25-50%).

Unlike testosterone tightly bound to sex hormone-binding globulin (SHBG), which is biologically inactive, the albumin-bound fraction can easily dissociate and become available for tissue uptake.

Bioavailable testosterone may provide a more accurate picture of your biologically active testosterone than total testosterone alone, especially when SHBG levels are abnormal.

Testosterone is produced mainly in the testes (men) and ovaries (women), with smaller amounts from the adrenal glands. The bioavailable fraction is determined by how much testosterone circulates unbound or loosely bound to albumin rather than tightly bound to SHBG.