Hypogonadism, or testosterone deficiency, the medical term for “low-T,” is measured by free-floating testosterone levels in the blood being below 300 nanograms per deciliter. Taking multiple blood samples over several days is recommended when evaluating for hypogonadism, as testosterone levels can fluctuate from day-to-day and are highest in the morning.

Hegseth said testosterone testing, which will be optional for service members under age 30, is intended for “keeping you on the leading edge of lethality and giving you the same level of support that you give this nation: the absolute best.”

Doctors react

Dr. Sevann Helo, a professor of urology at the Mayo Clinic in Minnesota, told the Washington Examiner that screening could be a useful tool to detect early warning signs of hypogonadism, which affects roughly 20% of males aged 15-39.

But Helo said most of this is attributable to co-morbidities, such as obesity and diabetes, that can be improved with diet and exercise. She said blood testing for testosterone can be used as “an additional tool for us to use in terms of counseling, talking about prevention, identifying and preventing health conditions.”

Stefan Pasiakos, a nutrition specialist at the Center for Human Performance Optimization at Louisiana State University, told the Washington Examiner that he would have liked more clarity from Hegseth and the Pentagon regarding the goal of the new policy.

Pasiakos is a former Army and Pentagon biomedical researcher whose work specialized in using supplemental testosterone to overcome the physiological stress of combat conditions. His research suggests that testosterone therapy can help reduce the negative effects of extremely little sleep, severe calorie constriction, and heightened physical activity on the battlefield.

But Pasiakos said he is not convinced that there are going to be a whole lot of “low-T” service members found by the new screening protocols.

“Just broadly canvassing all service members for testosterone, I just don’t think you’re going to see as much clinical hypogonadism as you think,” Pasiakos said. “It’s going to be like the general population for that age of individual.”

The Endocrine Society issued a statement on testosterone screening on Thursday, following Hegseth’s announcement, saying that a diagnosis of hypogonadism depends not just on consistently low testosterone levels in multiple blood tests, but also on physical symptoms.

“There is insufficient evidence to support a general recommendation to perform population-level screening for hypogonadism in asymptomatic men with measurement of blood testosterone level,” the Endocrine Society statement reads.

The downside risks

Testosterone replacement therapy is not without risks, including cardiovascular problems such as blood clots, stroke, and heart attacks, and prostate cancer risks. Side effect risks for TRT increase if the protocol is used for performance enhancement rather than to treat hypogonadism.

Helo said her main concern with blanket testing of young males in the military is long-term damage to fertility.

“It is an important counseling point with young men that they know that while on testosterone will definitely suppress sperm production, and in a very small minority of patients, may have lasting effects even after coming off of testosterone therapy, so that’s a key point for the young population,” Helo said.

HEGSETH’S ‘HIGH-T’ TESTOSTERONE INITIATIVE: WHAT TO KNOW

Helo said it is important that patients have symptoms of testosterone deficiency, such as a loss of muscle mass or diminished sex drive, as well as low hormone levels in their blood tests. She recommends not pursuing treatment just because of low test results, but rather treating the whole patient.

“We always say treat the patient, not the number,” Helo said. “And so we want to make sure that testosterone, while it can be life-changing, make sure we’re doing it in the right patient.”