Free testosterone measures the biologically active portion of testosterone not bound to SHBG or albumin.

Diagnostic Value: It provides a direct indicator of androgen activity. Low free testosterone may signal hypogonadism, while elevated levels can point to PCOS or adrenal overactivity.

Clinical Importance: This test is especially useful when total testosterone appears normal but symptoms suggest imbalance.

Symptom Correlation: Fatigue, decreased libido, hair loss, or muscle weakness may relate to low free testosterone; acne, excess hair, or irritability may relate to high levels.

Free testosterone testing offers a clearer view of true hormonal activity affecting vitality and reproductive function.