Free testosterone concentration in serum/plasma

Why This Test Is Done

Your healthcare provider may order this test to evaluate hormone balance, especially if you have symptoms like low libido, fatigue, or changes in hair growth. It’s often used in men with suspected low testosterone or women with irregular menstrual cycles, fertility issues, or symptoms of hormonal imbalances.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the blood draw if your test involves a fasting sample. Wear comfortable clothing and plan to rest for a short time afterward, as you’ll need to sit still while blood is drawn.

What the Results Mean

Results are compared to general reference ranges for your age, sex, and health status. Low free testosterone may indicate conditions like hypogonadism, while very high levels could signal hormonal disorders or medications affecting testosterone metabolism.

Common Conditions Linked to Free Testosterone

Abnormal free testosterone levels can signal conditions such as primary or secondary hypogonadism (low testosterone production), Cushing’s syndrome (high cortisol affecting testosterone), or polycystic ovary syndrome (PCOS) in women. It may also help diagnose androgen insensitivity or evaluate treatment responses in hormone therapy.