The free androgen index (FAI) is a ratio for testosterone that is calculated after a blood test to find out if you have abnormal androgen levels. This index compares the levels of total testosterone and the levels of a carrier protein called steroid hormone binding globulin (SHBG), to find out the amount of free and active testosterone in your body.
Sources:
- University of Rochester Medical Center. Free Androgen Index. https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=free_androgen_index (accessed 3. August 2020)
- Pinola P. et al. Androgen Profile Through Life in Women With Polycystic Ovary Syndrome: A Nordic Multicenter Collaboration Study. The Journal of Clinical Endocrinology & Metabolism, Volume 100, Issue 9, 1 September 2015, Pages 3400–3407. https://academic.oup.com/jcem/article/100/9/3400/2836076
