Serum or plasma concentration of free (unbound) testosterone

Why is this test done?

Your doctor may order this test to evaluate hormone levels in conditions like infertility, hormonal imbalances, or to monitor treatment for disorders such as polycystic ovary syndrome (PCOS) or androgen excess. It can also help diagnose or monitor conditions like hypogonadism or hyperandrogenism.

What does a result mean?

Results are interpreted based on your sex, age, and overall health. High levels may suggest conditions like Cushing’s syndrome or androgen-secreting tumors, while low levels could indicate hormonal deficiencies or disorders like hypogonadism. Your doctor will consider these factors alongside your symptoms and other test results.

Sample preparation and timing

This test requires a blood sample drawn in the morning (ideally between 7 AM and 10 AM) for the most accurate results. Avoid testing after recent exposure to certain medications, alcohol, or stress, as these can affect hormone levels. Fasting is not required unless specified by your doctor.

Common reasons for abnormal results

Abnormal results may indicate hormonal imbalances, such as low testosterone in men or women with androgen deficiency, or high testosterone in conditions like PCOS or tumors. They can also signal issues with the pituitary gland, ovaries, or testes. Your doctor will discuss these findings with you and may recommend further testing or adjustments to treatment.