No, red light therapy isn’t a medically approved treatment for increasing testosterone

Fox News host Tucker Carlson recently interviewed personal trainer Andrew McGovern, who advocates for the use of red light therapy to increase testosterone levels in men as part of his “Tucker Carlson Originals” series. 

During the interview, Carlson refers to red light therapy as “testicle tanning,” a phrase shared widely on social media platforms like Twitter. This comes as Carlson is promoting his documentary “The End of Men,” which states that decreasing testosterone levels in men is a problem in the U.S. 

A urologist said later in a viral tweet that there is “absolutely no data on testicle tanning,” adding that it doesn’t stimulate the production of testosterone.

THE QUESTION

Is red light therapy a medically approved treatment for increasing testosterone levels? 

THE SOURCES

• Cleveland Clinic
• Amin Herati, M.D., director of male infertility and men’s health and assistant professor of urology at Johns Hopkins School of Medicine
• Adam Friedman, M.D., professor and chair of dermatology at The George Washington School of Medicine and Health Sciences
• Study on the impact of low-level light therapy in testosterone production conducted on rats
• Study on a lack of interest in sex being treated by exposure to bright light

THE ANSWER

No, red light therapy isn’t a medically approved treatment for increasing testosterone levels. 

WHAT WE FOUND

Red light therapy is often promoted as a treatment for common skin woes, such as stretch marks, scars, acne and others, along with improving hair growth and reducing inflammation. Cleveland Clinic says red light therapy, which is also known as low-level laser light therapy and low-power laser therapy among other names, is an “emerging therapy but holds a lot of promise.”

During red light therapy, you expose your skin to a lamp, device or laser with a red light. It’s thought to work by acting on the “power plant” in your body’s cells called mitochondria. With more energy, cells can work more efficiently to do things like repairing a person’s skin. 

But red light therapy isn’t approved as a medical treatment for increasing testosterone levels – and many experts don’t recommend it. 

The U.S. Food and Drug Administration (FDA) has approved oral testosterone capsules like Jatenzo as a treatment for men with low testosterone levels due to certain medical conditions. 

According to men’s health website prostate.net, the FDA hasn’t approved any light therapy devices to increase testosterone production. There are red light therapy devices available online that don’t need FDA clearance, but they aren’t meant for raising testosterone.

One medical professional who spoke to VERIFY said red light therapy could do more harm to testosterone levels than good. 

“The risks of it come with temperature changes as you elevate the temperature of the scrotum. If there is a temperature increase, sperm production will diminish, testosterone production will diminish, so there's that potential,” said Amin Herati, M.D., director of male infertility and men’s health at Johns Hopkins School of Medicine.

Additionally, there is “absolutely no controlled study” that proves red light therapy increases testosterone, Adam Friedman, M.D., professor and chair of dermatology at The George Washington School of Medicine and Health Sciences, said. The science is “just simply not there.” 

There are some studies that show low-level light therapy or low intensity red light could increase testosterone levels. But they were conducted on animals like rats and birds – not humans. 

A 2013 study on 30 six-week-old rats found that low-level light therapy “might be an alternative treatment modality to the conventional types of testosterone replacement therapy.”

Some proponents of red light therapy also point to a 2016 study conducted by researchers at the University of Siena in Italy that focuses on a lack of interest in sex being remedied by exposure to bright light. But those researchers studied a relatively small group of only 38 men.

One group received regular treatment with a specially adapted light box, while the control group received treatment with a light box that gave out “significantly less light,” researchers said. After two weeks of treatment or placebo, researchers found that those who received treatment through higher levels of light had increased testosterone levels and reported greater levels of sexual satisfaction. 

One reason could be that light therapy inhibits the pineal gland in the center of the brain, which “may allow the production of testosterone,” researchers said. 

Though the study found some indication the treatment might increase testosterone, the researchers still said they could not yet recommend light therapy as a clinical treatment. It may be a viable solution to a lack of interest in sex if it’s “shown to work in a larger study,” they added. 

Many published studies looking into red light therapy for a variety of uses apart from testosterone production have only included a small number of people, were absent a placebo group, or were limited to animals as well, Cleveland Clinic says. 

‘Testicle tanning’ is a misnomer for red light therapy

The way Carlson referred to red light therapy – as “testicle tanning” – is also a misnomer. 

Red light therapy uses low wavelength red light, Cleveland Clinic explains, unlike cancer-causing UV rays from the sun or tanning booths. That’s why medical professionals say it appears to be safe for treating certain skin conditions.

There’s no such thing as a safe tan, since it’s actually the way skin responds to being injured or harmed by ultraviolet radiation in an effort to limit further damage, Friedman said. Exposure to UV rays can also lead to painful sunburns and increase the risk of developing skin cancer. 

It’s unlikely that a tanning bed or direct exposure to sunlight will increase testosterone production in the testicles, either, according to Herati. 

“For the light to be able to reach the testicles, it has to penetrate through multiple layers of tissue – has to go through the skin, the layer muscle under the skin, a couple other layers of fascia before it reaches the lining of the testicle and it has to penetrate within the testicle,” he said. “So the likelihood that the UV would be able to penetrate would be unlikely in that situation, or to have an effect.”

Some natural ways that men can boost their testosterone include a healthy diet, an exercise routine that incorporates cardio and strength training, and getting enough sleep, experts say. 

More from VERIFY: No, there’s no evidence that COVID-19 vaccines cause infertility in women or men