Courtesy of medichecks results page following my tests;
The free androgen index (FAI) is a calculation used to determine the amount of testosterone which is free (unbound) in the bloodstream. Most testosterone is bound to proteins sex hormone binding globulin and albumin and is not available to interact with the body's tissues. The FAI is a calculation based on the ratio of testosterone and SHBG and is a measure of the amount of testosterone that is available to act on the body's tissues.
In women the free androgen index can be useful in assessing symptoms like acne, unwanted hair growth, and hair loss which are often seen in polycystic ovarian syndrome.
What might a low result mean?
A low free androgen index could be a sign of lower than expected testosterone levels (androgen insufficiency). This can cause symptoms such as loss of libido, fatigue, and may also have an effect on bone health.
What might a high result mean?
An increased free androgen index is a sign of excessive testosterone. In women this is most commonly caused by polycystic ovarian syndrome.
