What to know about testosterone replacement therapy and the U.S. military’s testing plan

Testosterone replacement therapy is drawing renewed attention after Defense Secretary Pete Hegseth said the U.S. military will test service members’ testosterone levels and offer treatment to those who qualify. The move comes as the therapy has become more common in men’s health clinics, telehealth services and online promotion, with prescriptions rising in recent years. Doctors say the treatment is intended for men with clinically confirmed low testosterone, not as a general fix for aging, fatigue or performance. A diagnosis usually requires symptoms plus repeated morning blood tests and an evaluation for underlying causes such as sleep disorders, obesity, chronic illness or certain medical treatments. Experts say testosterone therapy can help appropriate patients with symptoms, bone density, muscle mass and mood, but it also carries risks. These include higher red blood cell counts, fertility problems, acne, fluid retention and possible worsening of sleep apnea. Research has not shown clear evidence that raising testosterone in men without a medical need improves broad health or performance. The military plan raises additional questions because intense training, sleep loss and physical stress can temporarily lower testosterone levels. Doctors caution that a low reading in that setting may not mean a lasting deficiency, and they say treatment should not be seen as a shortcut to better military performance.