More testosterone won’t make a better soldier or a tougher man – aggression and strength drive T levels, not the other way around

How low is too low when it comes to testosterone levels? When Defense Secretary Pete Hegseth announced in July 2026 that U.S. service members ages 30 and older will have their testosterone tested every year, neither he nor the Pentagon specified what level of the hormone would be considered “low” enough to require treatment – a telling omission, since where “low” begins depends on the lab conducting the test and the guidelines your doctor follows.

The announcement lands amid a national testosterone craze: Prescriptions have climbed to nearly 12 million in 2025, up 154% since 2020, and fastest among men in their late 30s and 40s. Online clinics that sell testosterone as a lifestyle upgrade have largely driven this rise in prescriptions.

As a psychologist who studies masculinity, I’m certain that while the idea that more testosterone makes a man tougher and more fit to fight seems intuitive, it’s also mostly wrong.

What testosterone actually does

Testosterone is often considered a “male” hormone, but people of every gender produce it in differing amounts.

In cisgender boys and men, testosterone levels rise at puberty, helping build muscle, grow body hair and produce sperm. Levels naturally decline in adulthood, typically beginning age 30 and onward. When levels drop significantly below normal and a person begins to experience symptoms such as extreme fatigue, low libido or drastic muscle loss, testosterone replacement therapy with medical supervision can help.

But “normal” is a vast range. Endocrinologists consider testosterone levels between roughly 300 to 1,000 nanograms per deciliter as healthy. Within that range, a man’s testosterone level tells you little about the “masculine” traits that some people think it governs.

Testosterone is tied to muscle mass, but in healthy men, it doesn’t track with actual strength – training, sleep and nutrition matter far more. As endocrinologist Adrian Dobs put it, a person at 700 isn’t stronger or more of a man than one at 300.

Moreover, an individual’s testosterone levels aren’t fixed – they swing by the hour and the season. So doctors usually test testosterone levels only when symptoms appear. Screening healthy men by the millions may be potentially harmful.

For instance, testosterone therapy often carries risks. Supplementing the hormone signals the body to shut down production of its own supply, which can shrink the testicles and suppress sperm. Some researchers have even studied testosterone for its contraceptive effects.

Moreover, because testosterone revs up oil glands and hair follicles – and partly converts them to estrogen – it can also bring about acne, balding and even some breast tissue growth.

This “high-T” ideal – sold by online clinics and now endorsed from the top – glosses over these severe risks.

The macho myth

Decades of research undercut Hegseth’s core claim that more testosterone means a more aggressive, dominant, masculine man.

A 2001 analysis of data from 45 studies covering nearly 10,000 people found only a small correlation between testosterone levels and aggression. When researchers pooled data in 2020 from experiments that actually administered testosterone to participants to study whether it causes aggression, they found only weak evidence. In fact, they saw that the effects of testosterone on aggression primarily showed up in men who were more dominant or impulsive.

If anything, the arrow runs the opposite way – behavior drives testosterone levels. One study found that men who handled a gun for 15 minutes had bigger testosterone spikes and acted more aggressively than men who touched a board game. Meanwhile, the testosterone levels of new fathers fell more steeply the more they physically cared for their child.

When men do demonstrate aggression, the trigger is typically social. In my own research, threatening a man’s sense of manhood – but not a woman’s womanhood – reliably provokes aggression, and the men who react most strongly are those who feel the most pressure to live up to masculine ideals.

The link between aggression and the fear of failing at manhood takes root early. In a study of more than 200 adolescent boys and their parents, my team and I found that boys who reacted aggressively to threats to their masculinity were mainly those who felt external pressure to be masculine. That pressure was strongest among boys whose parents endorsed specific beliefs about manhood, like the idea that men should hold power over others.

Biology, social pressure and development work together to determine how a boy grows into a man. Unlike Hegseth’s story that manhood is a chemical to be topped off, research shows that while hormones may open a window, the social environment decides what comes through.

Military life lowers testosterone

Ironically, the grind of military service can drive down a man’s testosterone levels.

A 2020 study of U.S. Army Rangers found that the sleep loss built into training significantly reduced testosterone levels.

Chronic stress, sleep deprivation, blast exposure and poor nutrition can produce a cluster of health problems called “Operator Syndrome.” In some cases, the work conditions of special operators can push a 35-year-old’s testosterone levels toward those typical of a man in his 80s.

Notice the loop: The military imposes the very conditions that suppress testosterone, then proposes to fix the result with more of it. The psychologist who named Operator Syndrome cautioned that handing troops testosterone won’t restore their health, because the real culprits are sleep, stress and injury.

Double standards

In February 2025, the Pentagon halted gender-affirming hormone therapy for transgender troops, framing such care as incompatible with the force’s “readiness” and “lethality.” Yet prescribing testosterone to bring a cisgender man’s body in line with the Pentagon’s masculine ideals is hormone therapy, too.

Legal advocates flagged the contradiction at once: The same class of medication is disqualifying for one group of service members, but for another, it’s rebranded as optimizing the soldier.

So a testosterone mandate won’t build tougher soldiers – if anything, it reveals an anxiety no hormone can fix. My research argues that the men most pressured to prove their manhood are the ones who most experience it as fragile, treating masculinity as a status that can be lost and must be won back again and again.

Telling troops that their readiness hinges on a test result can deepen their anxiety around manhood. Real strength – the kind that holds up under fire – is not something that can be topped off with a hormone. Although testosterone is biologically useful, it isn’t the measure of a man or soldier.