Tucker Carlson is obsessed with testicle tanning to save American manhood. A urologist says it could backfire.

• Fox News Host Tucker Carlson has a documentary touting the so-called benefits of testicle tanning.
• A practicing tanner says during the show that, according to "bro science," it increases the health of the testes.

Fox News Host Tucker Carlson is out with his documentary touting the so-called benefits of testicle tanning as a testosterone booster, months after the show's preview triggered a social media giggle fit.

In the Tucker Carlson Originals' "The End of Men" episode, Carlson introduces viewers to a "growing movement of Americans" who call themselves "bro scientists" and who are trying out experimental ways to balance hormones, regain fertility and get healthy. They may "slonk" raw eggs, lift weights, take cold showers — or, direct shiny red lights at their manhood.

"My name on Twitter is Benjamin Braddock, I'm a right-wing bro scientist, and yes, I tan my balls," the man says as a light machine pointed at a spread-eagle nude dude sets his genitals aglow.

This self-described "writer, beauty appreciator, raw egg slonker" says the bro science behind testicle tanning is that it can increase the cellular energy and health of the testes.

But urologist Rena Malik, however, told Insider, "It's definitely not going to help you."

"It's not going to work," said Malik, who practices at the University of Maryland Medical Center. "There's no empirical evidence that it works and it doesn't make sense that it would work."

Malik, who posts weekly educational YouTube videos about urologic, sexual, bladder health, released a video on testicular tanning in April, back when Carlson previewed his second season of Tucker Carlson Originals.

"I was worried," she said. She feared people would waste their money, burn their skin, and delay needed care by treating themselves "with lights that don't work."

Carlson is also worried — about what he says is the "total collapse" of testosterone in American men, calling it "one of the biggest stories of our lifetimes." And to those who think testicle tanning is"crazy," he says in his season preview that no one saying anything about crashing testosterone levels is "crazy."

Enter Kid Rock, the right-wing singer with the pushback: "Dude, stop, testicle tanning, come on. I haven't heard anything that good in a long time..." Carlson encouraged him to "open your mind..."

"Why wouldn't open-minded people seek new solutions?" Carlson asked a flabbergasted Kid Rock, who shook his head and said, "I don't know what the hell is going on in this world..."

If Malik were asked about testicle tanning 10 years ago, she wouldn't have believed it, she said. But misinformation has become so commonplace, particularly with COVID in the medical field, she's not surprised.

"I mean, people are really looking for hacks to improve their life" and they've lost faith in the scientific community to do the research, she said. They forget that there's a placebo effect that can make people think something like testicle tanning is working when it's really just the brain working to improve symptoms.

If used as instructed, Malik said, the products are "probably low risk." But it's also possible that it could have the unintended effect of reducing – as in, not increasing – sperm count, if the light were to increase the temperature of the testicles.

Semen analyses taken after a patient has had a fever, for example, will show zero sperm because the temperature increase stops testosterone temporarily, she said. But the impact of light therapy on sperm count hasn't been studied.

"If you increase the temperature of the scrotum enough that it affects the testicles, it could cause changes in reduced … sperm production," she said.

Some people use red light therapy for certain skin conditions because it penetrates and increases cellular activity in the skin and improves blood flow. People, in theory, could extrapolate that increasing blood flow could help testicles produce more testosterone.

But testosterone is made in the testicles and light wouldn't even penetrate them, just the scrotal skin, she said. So there wouldn't be any impact on testosterone production, she said.

It's true she has been seeing more younger men with low testosterone, which could be associated with a low libido and fatigue. Endocrine-disrupting chemicals in the environment and less testosterone-boosting activity could be factors as men sit more and get less sunlight and good sleep, she said.

What can help? High intensity interval training, resistance training, seven or more hours of quality sleep, a diet that's devoid of ultra-processed foods, and avoiding chemicals like BPA.

"It's not tanning your testicles," she said. "It's really working on having healthy food…and getting exercise and moving your bodies, which I think is really lacking in society."