What is testosterone screening, and why is the U.S. military introducing it? | Explained

The U.S. Department of Defense has announced mandatory annual testosterone screening for all active-duty service members aged 30 years and above. Announced by U.S. Defence Secretary Pete Hegseth on July 15, the policy will make testosterone testing part of routine annual medical assessments. Personnel found to have low testosterone may undergo further clinical evaluation and can choose whether to receive testosterone replacement therapy (TRT), while those below 30 years may request testing voluntarily.