Free Androgen Index

FREE ANDROGEN INDEX Test

The Free Androgen Index (FAI) is a calculated value used to estimate the amount of biologically available testosterone in the blood. It is generally calculated using total testosterone and sex hormone-binding globulin (SHBG) levels.

FAI can help assess androgen status, particularly when symptoms suggest excess androgen activity. It is commonly considered during evaluation of conditions such as polycystic ovary syndrome (PCOS), excessive facial or body hair (hirsutism), acne, irregular menstrual cycles, or other hormonal disorders.

In women, an elevated FAI may indicate increased androgen activity. In men, testosterone and SHBG measurements may be interpreted differently depending on the clinical situation. FAI should be assessed along with symptoms and other hormone tests rather than used as a standalone diagnostic test.

This Test is Recommended for Individuals:

• Women being evaluated for suspected PCOS
• Individuals with excessive facial or body hair (hirsutism)
• Women with irregular or absent menstrual periods
• Individuals experiencing unexplained acne or androgen-related symptoms
• Patients being evaluated for suspected androgen excess
• Individuals with suspected hormonal or reproductive disorders
• Patients requiring assessment of testosterone availability along with SHBG and total testosterone

FAQs

1. What does the Free Androgen Index measure?
FAI is a calculated estimate of free or biologically available testosterone, based primarily on total testosterone and SHBG levels.

2. What does a high Free Androgen Index indicate?
A high FAI may suggest increased androgen activity. In women, it can be associated with conditions such as PCOS and other causes of androgen excess. Further evaluation is usually required to determine the cause.

3. Is the Free Androgen Index the same as a Free Testosterone test?
No. FAI is a calculated estimate based on testosterone and SHBG, while a Free Testosterone test directly measures or estimates the unbound testosterone concentration using a specific laboratory method.