Debate about the Free Testosterone Hypothesis: Useful Tool or Misguided Mirage?

In this debate, two clinicians discuss the merits and demerits of the free testosterone hypothesis. Although most clinical guidelines recommend the measurement of free testosterone in the evaluation for male hypogonadism (at least in men with suspected low serum sex hormone binding globulin), there remains controversy about underlying hypothesis that serum free testosterone is a significant contributor to androgen effect. In this debate, Dr. Anawalt presents evidence to support the free testosterone hypothesis and advocates for the usefulness of accurate assessment of free testosterone in the evaluation of male hypogonadism. Dr. Handelsman argues that the evidence is unconvincing, the hypothesis is flawed and biologically invalid, and free testosterone cannot be accurately assessed in clinical practice.