America is reaching peak testosterone.
In 2026, interest in the hormone is everywhere, from T-maxxing trends on social media to the US government’s MAHA campaign. Testosterone replacement therapy (TRT) use has quadrupled in the past three decades, up to as many as 11 million Americans.
For some of them, the treatment may be doing more harm than good, new research suggests.
A majority of men who are prescribed testosterone don’t meet the current guidelines for safe, effective treatment, according to a study from the University of Michigan.
That could worsen the risk of serious side effects, including infertility, heart attack, and stroke, and long-term dependence on TRT, which can dampen the body’s natural production of testosterone.
While testosterone is an essential hormone for health, finding the right balance is complex because there’s no one-size-fits-all treatment. A urologist explains what to know about the risks and benefits of testosterone, and how hormone trends are changing the landscape of men’s health.
Who can benefit from testosterone therapy?
Healthy testosterone levels are crucial for energy, sex drive, muscle, and metabolism.
T-maxxing influencers might promise that it can get you a six-pack and supercharge your focus and performance, but doctors say the benefits are much more modest — if you need a boost at all.
A blood test can check if you have low testosterone and could benefit from TRT. It’s typically taken first thing in the morning, and confirmed with a follow-up blood test on a different day.
Low testosterone is anything below 300 nanograms per deciliter for most healthy adult men.
You should also rule out conditions like sleep apnea, which are linked to low testosterone but can worsen with testosterone therapy.
Men who could benefit from testosterone might experience symptoms ranging from brain fog and low energy to reduced libido and erectile dysfunction. It can take anywhere from a few weeks to a few months for TRT to make a difference, depending on the symptoms.
When T backfires
In the latest research, endocrinologists looked at data from 200 men who were prescribed testosterone at the university clinic.
They found that only 12% of the men met the criteria for treating low testosterone, confirmed by two blood tests.
That means the other 88% — 176 men — may have been inappropriately given TRT, including some who had sleep apnea or prostate cancer.
On average, the men studied were in their 50s, but some as young as 18 were also prescribed testosterone.
If they don’t need it, young men on testosterone could be putting their long-term health at risk, since taking TRT can make it harder for the body to produce its own supply of the hormone over time.
High testosterone levels can also increase the body’s volume of red blood cells, a risk factor for high blood pressure that, in extreme cases, may lead to a heart attack or stroke. It can also impair fertility by temporarily reducing sperm count.
And taking T can potentially exacerbate serious health conditions like prostate cancer, potentially fueling tumor growth, per the Mayo Clinic.
The findings are concerning, given how popular testosterone has become in the wellness industry and the potential for misuse without clear guidelines, said study authors Dr. Maria Papaleontiou and Dr. Sophia Sinha, both professors at the University of Michigan.
“Testosterone has been coined as the ‘fountain of youth’ to optimize performance through enhancing muscle and improving energy levels in social media,” they told Business Insider in a joint email interview. “Testosterone therapy can help some people who truly have low testosterone, but it is not risk-free.”
Major update coming soon for testosterone therapy guidelines
Doctors understand that this is not a black-and-white issue.
While testosterone treatment can have side effects, low testosterone is also a health concern, Dr. Justin Dubin, director of men’s sexual health at Baptist Health Medical Group, told Business Insider.
Dubin, who was not involved in the study, said prescribing TRT outside the guidelines may not always be harmful. Yes, TRT can be overprescribed to men who don’t need it, but it is also underprescribed to men who could benefit, Dubin said.
“Guidelines are guidelines, they’re not law,” Dubin said. “There are gray areas, and we need to give care in the gray. That’s where most doctors live and where most patients live.”
The benchmark for healthy testosterone is so nuanced, Dubin said, that the American Urological Association has gathered a panel to discuss a major update to its guidelines on treating testosterone deficiency in the coming year or two.
For now, Dubin said the growing popularity of testosterone is a good thing, as it’s prompting a more proactive approach to medical care for men, who are notorious for avoiding the doctor’s office until there’s an emergency. As long as guys are going about it the right way by speaking to their doctor instead of just buying stuff online, he’s all for it.
“I think that’s a wonderful thing because this is a gateway to men’s health. This is how we can access a lot of guys, get them in to learn about their blood pressure, whether they have diabetes, heart disease,” he said. “I’m actually excited and hopeful.”