Opinion: Beware the unintended consequences of testosterone screening for military servicemembers

OpinionFirst Opinion Beware the unintended consequences of testosterone screening for military servicemembers This unprecedented experiment will require careful implementation and monitoring Manage alerts for this article Email this article Share this article By Alexander P. ColeJuly 18, 2026 Cole is a board-certified urologist. When I first heard the announcement on Wednesday that the Department of Defense will begin a mandatory testosterone screening program for service members, my mind naturally leapt to a series of questions derived from my career studying men’s health and population-level screening in men’s health. In particular, I fear that the widespread rollout of testosterone screening may lead to some surprising and unintended consequences that must be carefully weighed if we want to prioritize the health of U.S. servicemembers. As a practicing urologist and health outcomes researcher, I have seen firsthand how testosterone supplementation has received growing interest in recent years. I have also studied the impacts and implementation other types of screening tests, including among military servicemembers. As with any type of population-level medical screening, a careful examination of risks and benefits is vital.Advertisement Regarding testosterone supplementation specifically, the interest of some patients has at times outpaced our scientific and medical understanding of testosterone deficiency and its management. The decision to roll out widespread screening of U.S. service members is unprecedented — and it may lead to thorny downstream effects. Testosterone is, of course, a well-known sex hormone. Its levels are the result of a complex interactions of multiple systems inside of the brain and body. This system, the hypothalamic-pituitary-gonadal axis, helps to develop the male reproductive organs in utero, results in the changes seen during puberty, and is associated with some behavioral characteristics such as aggression and sex drive. The medical management of testosterone levels and their role in aging is a topic of great interests to scientists, physicians, and aging men. It has long been known that testosterone levels decrease as men age. Additionally, many of the symptoms of aging such as gains in body fat, osteoporosis, and decreases in libido are also seen in some conditions with disruption of the hypothalamic and pituitary glands (for example, some genetic syndromes, intersex conditions, and certain types of pituitary tumors). Further complicating this system, some conditions (e.g., obesity, sedentary lifestyles, and certain diets) can themselves reduce testosterone levels.Advertisement Because of this, there has been legitimate interest throughout the medical community in testosterone supplementation to slow the effects of aging and improve energy in older men. Against this backdrop, there’s been an explosion of interest in recent years in testosterone therapy among middle-aged and older men with testosterone levels below reference ranges for young men. Often these men have lower than normal levels but do not have disorders of the hypothalamic and pituitary system. The global market for testosterone therapy has exploded from global sales of only $18 million annually in the late 1980s to nearly $2 billion in 2025. In many cases, this growth has been fueled by direct-to-consumer marketing, online prescribing systems, wellness communities, and online influencers. While many patients who use these medications are managed appropriately, I have seen others who obtain these medications through loosely regulated online marketplaces and at times come in with testosterone levels many times higher than what is considered a normal and safe level. There is no question that testosterone replacement therapy can increase muscle mass, libido, and in some cases may result in changes in mood and behavior that some men find appealing. But testosterone supplementation is not without risk. In 2010, the TOM study (Testosterone in Older Men with Mobility Limitations) was halted early due to a higher incidence of major cardiac events (including heart attacks and strokes) in those taking testosterone replacement therapy. More recently, the Testosterone Replacement Therapy for Assessment of Long-term Vascular Events and Efficacy Response in Hypogonadal Men (TRAVERSE) trial published in 2023 failed to reproduce this finding. It actually showed that testosterone therapy was no worse than placebo in terms of the odds of adverse cardiac events. However, that study also found a higher incidence of acute kidney injury, atrial fibrillation, and pulmonary embolism in those taking testosterone replacement therapy.Advertisement My own research group was part of an effort to study health outcomes of military servicemembers. As part of that effort, we evaluated side effects of testosterone replacement in men covered by the military’s health insurance (TRICARE). In these DOD-supported studies, my colleagues and I found higher rates of kidney stones and obstructive sleep apnea in military beneficiaries who used testosterone supplementation — although the latter study showed a significant improvement in cardiovascular disease outcomes. As these studies make clear, testosterone replacement therapy comes with potential benefits as well as risks. Of particular interest to men in younger age ranges — Defense Secretary Pete Hegseth said Wednesday that members of the military ages 30 and over will be tested — testosterone replacement therapy reduces testicles size and sperm counts. Both the American Urological Association and the Endocrine Society guidelines caution against testosterone usage in men who plan to have children due to the impact on fertility. At the very least, the decision to screen for and treat low testosterone levels warrants an individualized and detailed discussion regarding potential risks. Testosterone measurements themselves are subject to confounding and need to be taken at specific times of day with a second confirmatory test and alongside other markers (including blood counts and other hormone levels) in order to confirm the diagnosis of low testosterone and identify potential causes. Men also need to be screened for conditions that may worsen with testosterone replacement such as sleep apnea, high risk for prostate cancer, heart failure or heart disease, or urinary symptoms of thrombophilia (high levels of red blood cells). Once a protocol is started, testosterone replacement requires monitoring to ensure that treatment is effective as well as monitoring for side effects. Of note, current Endocrine Society guidelines recommend against routine population level screening of asymptomatic men for hypogonadism and recommend against routine supplementation for younger men with low testosterone levels. These recommendations would seem to be at odds with the recent Department of Defense directive.Advertisement In his announcement, Hegseth that it would be up to individual servicemembers to decide whether to take supplements if their testosterone levels are found to be low. To help them make that decision, patients deserve careful counseling about the risks and benefits and an individualized approach incorporating individuals’ preferences, individual physiology, and (critically) personalized monitoring for side effects and appropriate treatment response. Rolling out personalized monitoring at the scale required for the entire Department of Defense health system will be a challenge to implement, but is critical if this initiative is to be done safely. The decision to roll out widespread population-level testing in U.S. servicemembers represents a novel experiment without any clear precedent in this area of medicine. For the wellness of members of the military, it will be critical that this widespread testing program is accompanied by careful monitoring at both the patient and population level to ensure that it is done in a way that is safe and appropriate. Alexander Cole, M.D., is a board-certified urologist. STAT’s coverage of health challenges facing men and boys is supported by Rise Together, a donor advised fund sponsored and administered by National Philanthropic Trust and established by Richard Reeves, founding president of the American Institute for Boys and Men; and by the Boston Foundation. Our financial supporters are not involved in any decisions about our journalism. Letter to the editor Have an opinion on this essay? Submit a letter to the editor. aging, Men’s and Boys’ Health, wellness Submit a correction requestReprints Alexander P. 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