Pentagon testosterone plan renews scrutiny of replacement therapy

The U.S. military will begin testing service members’ testosterone levels and offer replacement therapy to those who qualify, according to Defense Secretary Pete Hegseth. The plan arrives as U.S. testosterone prescriptions have climbed from 7.3 million in 2019 to more than 11 million in 2024, according to IQVIA, and as the Trump administration promotes wider access to therapies made by companies including AbbVie, Pfizer and Marius Pharmaceuticals.

Hegseth said the military effort is intended to help troops perform at their “absolute best,” NBC News reported. The announcement has brought renewed attention to a treatment that doctors say can help men with a confirmed hormone deficiency, while carrying risks if used without a clear medical indication.

Testosterone replacement therapy uses synthetic testosterone and is commonly delivered through injections, gels, implantable pellets or oral medication. Physicians generally reserve it for men diagnosed with hypogonadism, a condition in which the body does not produce enough testosterone.

Doctors cited by CNBC said diagnosis typically requires both symptoms and repeatedly low hormone readings. Symptoms can include reduced sex drive, erectile dysfunction, fatigue, depressed mood, lower bone density, and loss of muscle mass or strength. Marcus Goncalves, director of the Holman Division of Endocrinology, Diabetes and Metabolism at NYU Langone Health, said guidelines usually call for two separate morning blood tests because testosterone levels vary during the day.

Low readings do not necessarily mean a patient has a permanent deficiency. Dr. Richard Auchus, a professor of internal medicine at the University of Michigan, said testosterone can fall temporarily during severe stress, illness, weight loss or heavy exertion and then recover. Dr. Adrian Sandra Dobs, an endocrinologist at the Johns Hopkins School of Medicine, said doctors must be cautious about “overreplace” use, while noting that testosterone can benefit people who need it.

Benefits and risks

For men with clinically confirmed deficiency, physicians said therapy can improve sex drive, erectile dysfunction, muscle mass, bone density, energy and mood. It can also raise bone mineral density, which may reduce the risk of osteoporosis and fractures in men with low hormone levels.

Evidence is less clear for men whose testosterone is normal or only mildly low, according to the doctors cited by CNBC. Dobs said the therapy does not improve intelligence or make someone a better pilot, and experts said research does not support broad claims that testosterone works as a general anti-aging or performance-enhancing treatment.

The American Urological Association has said as many as one-third of men taking testosterone have not been formally diagnosed with testosterone deficiency and may not benefit from treatment. Doctors also point to risks that require monitoring, including increased red blood cell counts, acne, breast tenderness or enlargement, fluid retention, worsening untreated sleep apnea and reduced sperm production.

Goncalves said higher red blood cell counts can thicken blood and may raise the risk of complications such as clots. A major 2023 trial published in the New England Journal of Medicine found no higher rate of heart attack, stroke or cardiovascular death among men on testosterone therapy than among those receiving placebo, but researchers observed higher rates of atrial fibrillation, acute kidney injury and pulmonary embolism.

Military testing questions

The military setting complicates interpretation of hormone tests because training, sleep deprivation and prolonged exertion can suppress testosterone temporarily, Goncalves said. In a study of U.S. Marines undergoing Survival, Evasion, Resistance and Escape training, testosterone levels fell by about half during the exercise before recovering afterward.

Goncalves said there is no evidence that restoring testosterone during such periods improves performance, though he said the question could be studied. Auchus warned that long-term treatment can suppress natural testosterone production, creating potential dependence on therapy to maintain normal levels and raising operational questions if access is interrupted during deployment.

Doctors quoted by CNBC said testosterone replacement should be treated as a medical therapy for qualifying patients, not a shortcut to military performance. Dobs said testosterone will not make men “more macho or better fighters.”

This story draws on original reporting from CNBC.