Pete Hegseth’s Plan for ‘High T’ Troops Is a Junk-Science Fever Dream

US Defense Secretary Pete Hegseth has made no secret of his desire for a manlier military.

He consistently argues that the US Armed Forces lowered their combat standards in order to include women. He’s staged various photo ops in which he exercises and pumps iron with service members. In his speeches, Hegseth says that the Trump administration is restoring a “warrior ethos” to its legions of “war fighters.”

Now he has a rather dubious plan to guarantee that the troops are as macho as possible: testosterone screenings and, in cases where an individual’s testosterone is judged to be deficient, voluntary hormone therapy.

“Under the supervision of our world-class medical professionals, war fighters aged 30 and older are going to be tested annually as part of their periodic health assessment,” Hegseth said in a short video posted to his official X account on Wednesday. Those younger than 30 will be able to opt in to these evaluations as well, he explained.

“If treatment is recommended, it’s entirely your choice to receive testosterone replacement therapy,” Hegseth added.

Addressing service members directly, Hegseth said without offering evidence that the program would benefit “your performance, your resilience, and your long-term health.” He also declared that the initiative was “not about artificial enhancement,” but rather “restoring and optimizing your natural capabilities, protecting your longevity, and ensuring you have the biological foundation required to sustain the fight.”

Adrian Dobs, who researches endocrine gonadal function at Johns Hopkins University, tells WIRED that she was “quite surprised that this is what they’re thinking about,” and that “it’s a very complicated issue to make the diagnosis of male hypogonadism,” the medical term for when the testicles aren’t producing enough testosterone.

Dobs says that Hegseth seems to be radically oversimplifying the complicated issues around making a diagnosis of low testosterone—including the variability of testosterone levels depending on the type of assay (or analysis) performed and even the time of day the test is conducted.

Because of circadian rhythms, she points out, the hormone is typically seen at “higher levels in the morning and lower throughout the day.” Another logistical problem, Dobs says, lies in individual circumstances. It’s one thing to test, for example, “a healthy person who sits at a desk” and quite another to test a person who is returning “from basic training or overseas and may have lost weight and was under a great deal of physical stress at the time,” as chronic stress can inhibit testosterone production.

Hegseth’s view on testosterone itself is “misinformed,” according to Dobs. “Testosterone is a very important hormone,” she says, and it plays a key role in puberty and masculinization. “But it is not something that’s going to make you smarter. It’s not something that’s going to make you live longer—we simply don’t have any data to suggest that.” The longevity claim, she adds, would be incredibly difficult to prove in any case.

The Pentagon declined to comment beyond Hegseth’s description of the screening and treatment process, so it’s unclear what specific results the Defense Department expects to achieve by administering testosterone to untold numbers of active-duty service members, or whether women in the Armed Forces will also undergo hormone assessments. Neither has the Defense Department made public what scientific research and which medical experts, if any, informed this decision.

Aside from the problems with trying to define “normal” amounts of testosterone and standardizing the screening process, Dobs says, using testosterone replacement as an easy fix for deficiency ignores standard diagnostic practice, which is to identify and treat any underlying condition first. The potential root causes—from kidney or liver disease to diabetes—should be dealt with “before you launch into any hormonal intervention,” she says.