Low Testosterone Linked to 18% Higher Cancer Death Risk in 26,000-Man Study

Doesn't testosterone drive prostate cancer?

Doctors routinely lower testosterone to treat prostate cancer, so a connection seemed plausible. This review found none.

"Since reducing testosterone levels is a treatment for prostate cancer there's always been a question of whether the amount of testosterone your own body makes relates to your risk of prostate cancer, but based on our findings there's no evidence they are related," says senior author Bu Yeap, an endocrinologist at The University of Western Australia.

That matters because "low T" has become a catch-all explanation for nearly everything that ails aging men. Online influencers and a booming testosterone replacement industry have pushed that narrative well past what the science supports.

Should men take testosterone to cut cancer risk?

No — and the study's own author says so directly.

"While we've shown low levels are associated with increased risk, we haven't got any evidence yet that actually giving men testosterone will reduce that risk," Yeap says.

A 2023 randomized trial backs that caution. It followed more than 5,000 men with low testosterone for several years and found replacement therapy did not significantly change prostate cancer risk.

Previous research on testosterone and cancer mortality has been mixed, with some studies finding no association at all. This new review has two advantages. It drew only on studies that measured hormones with mass spectrometry, a more accurate lab technique than older methods. It also looked at the family of related hormones together, not testosterone in isolation.

Testosterone, produced by the testes and adrenal glands, shapes sexual function, muscle mass, bone health, and metabolism. Levels normally decline with age. But unusually low levels may signal that something else is wrong.

Yeap puts it plainly: low testosterone could serve as a biomarker of poor health — "so it's possible that looking at testosterone levels could help us identify men who might do poorly if they get cancer down the track."

What should men with low testosterone do?

Get checked. A low reading may not point to testicular disease, but it can flag other health problems worth catching early.

"What we would say to men is if they are found for whatever reason to be low in testosterone, it's important to go to the doctor for a full checkup," Yeap concludes. "It may not show any sign of testicular disease, but it might show other health issues or risk factors they need to address."

The bottom line: low hormone levels look like a warning light on the dashboard, not a cause of cancer — and no evidence yet says replacing the hormone turns that light off.