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........

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