Nearly half of the testosterone in your bloodstream is usually bound to a protein known as Sex Hormone Binding Globulin (SBHG). Testosterone in this form would not be able to enter the cells, and hence cannot be utilised. The other half is weakly bound to albumin which can be detached easily to increase utilisation of the testosterone. These are known as bioavailable testosterone. A very small percentage isn’t bound to any protein and these are known as free testosterone. All three forms make up total testosterone. Knowing your total, free and bioavailable testosterone levels is helpful in determining the actual biological activity of testosterone, which can affect mood changes, sex drive and cause other symptoms that may affect quality of life such as hair loss and fatigue. Screening for testosterone levels aids in identifying testosterone deficiency, which can be treated with hormone replacement therapy. This can significantly reduce the symptoms caused by the deficiency and improve quality of life for men.

SHBG is a protein produced by the liver and it controls the amount of sex hormones actively available in your bloodstream. The lower the SHBG levels, the higher the level of bioavailable hormones. Understanding your SHBG levels go hand in hand with identifying potential sex hormone imbalances.