Red light therapy has become the latest ray of hope in the wellness industry. If you listen to wellness influencers, you might think there's nothing that red light therapy can't treat. But what's the science behind the hype?
The claims
On TikTok, you'll find content creators touting red light therapy's benefits for skin care, hair growth, joint pain, sleep, longevity, inflammation — even period cramps.
As one TikTok creator who goes by Kristina Elise puts it, "If you invest in a red light therapy panel to have at home, your holistic wellness routine just got elevated."
And it's not just panels. There's a slew of red light face masks, wands, and special caps for hair growth sold for at-home use, ranging in price from as little as $50 or up to thousands of dollars. But are these devices really doing anything?
"This is the most commonly asked question that I get probably in the last four years," says Dr. Zakia Rahman, a clinical professor of dermatology at Stanford School of Medicine and faculty member at the Stanford Center on Longevity.
The science
Rahman says it can be challenging to distinguish science from hype when it comes to red light devices aimed at consumers. As for red light therapy itself — which is formally called photobiomodulation therapy, "there is actual real science. It's not science fiction," she says.
That science is based on how red light — which occupies the longer wavelengths on the visible light spectrum — impacts mitochondria, which are the powerhouses of cells. Rahman says both red and infrared light stimulate energy production inside mitochondria, so the cells work better.
"We create this energy through that red light and we can use it therapeutically to do things like grow hair, reduce inflammation, or create new collagen in our skin," Rahman explains.
She says scientists have known of red light's therapeutic potential since the 1960s, when a Hungarian researcher exposed mice to red light to see if it caused cancer. "It turns out they didn't grow cancer, but they grew hair," she says.
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The concept of light therapy seems less fantastical when you think of other ways in which light affects human health, says Dr. Praveen Arany, an associate professor and photobiomodulation researcher at the University at Buffalo. Light triggers vitamin D production and is a crucial driver of circadian rhythms. If we can use light physiologically, it makes sense that we can also use it therapeutically, he says.
The applications
With hair and skin, experts say it takes time to see the benefits of red light therapy — think months, not days, of consistent use, usually several times a week — the specific instructions vary by device.
And don't expect dramatic results, says Dr. David Ozog, a researcher and chair of dermatology at Henry Ford Health in Detroit.
For example, red light therapy has been shown to help treat androgenetic alopecia, or pattern hair loss – the most common cause of hair loss in both men and women. "It does help," Ozog says. "You can objectively look at the hairs, the quality of the hairs, the number of hairs, and they improve."
But how much it helps depends on many factors, including how far along your hair loss is. "It's not going to take you from being bald to being a Chia pet and having abundant hair," Ozog says.
As for skin, Rahman says evidence shows red light therapy can help improve fine lines and wrinkles, though the effects are modest compared to more aggressive treatments like laser peels that dermatologists can perform in the office.
"It may be helpful for some of the surface changes on the skin, for the superficial changes, but not for deep wrinkling," says Dr. Elma Baron, a dermatologist and professor at Case Western Reserve University School of Medicine. She notes there's also evidence the therapy can help with acne.
Ozog says he'd rank red light therapy below other proven treatments like retin A, vitamin C and light laser peels for skin rejuvenation.
As for other health claims, there's solid evidence that red light therapy is safe and effective for several medical uses, says Ozog. He was part of a panel of experts in various fields who wrote a 2025 consensus review that found the therapy works for treating pattern hair loss, ulcers, peripheral neuropathy, several types of ulcers and acute radiation dermatitis.
The therapy is also part of clinical guidelines to prevent and treat oral mucositis — painful mouth ulcers and inflammation that are common among patients undergoing treatments such as chemotherapy and radiation. "The red and infrared light does a fabulous job at calming that down," Ozog says.
There's also evidence the therapy can help reduce pain and modestly speed up healing from recurrent cold sores, he notes.
And in recent years, the Food and Drug Administration has authorized the marketing of red light therapy devices to treat dry age-related macular degeneration and for the temporary relief of pain from fibromyalgia.
For many conditions, red light is best viewed as a complementary therapy rather than a first-line treatment, Arany says.
Overall, when it comes to the health benefits of red light therapy, "in some areas we have reached the highest level of evidence. In the other areas, it remains more anecdotal," with promising evidence but more rigorous science needed, says Arany, who has worked with several companies in evaluating their red light therapy devices.
"The Wild West" of products
As for purchasing a red light device, "the buyer beware advice is it's a little bit like the Wild West," says Ozog.
While many devices for sale are FDA cleared, Ozog says that means they're safe but not necessarily effective. He's tested some that didn't actually put out enough energy to have any effect.
If you do buy, "I'd look for independent safety certification from a recognized lab such as Intertek or UL, plus separate third-party optical testing for wavelength and irradiance," Ozog advises.
Arany notes some devices sold online don't even emit the correct wavelengths to be effective.
And treatment isn't one-size-fits-all. Different wavelengths have been shown to be effective to treat different concerns for various lengths of time. For example, for skin rejuvenation, evidence suggests wavelengths ranging from 620 to 1072 nanometers can be effective. "Longer wavelengths are better because they penetrate deeper into the skin," Rahman says.
For pattern hair loss, wavelengths of 630 to 800 nanometers have been reported to be effective. If you do buy, look for a device that treats your specific concern.
Other caveats and potential concerns
"Red light is something that has a pretty high safety margin," says Baron.
That said, there are some safety concerns to be aware of. One is you should protect your eyes when using a red light device. Ozog warns that prolonged exposure to red or infrared light could damage your retina. "It's possible you could cause some harm," he says. Many devices come with goggles or other eye protection.
Another potential concern: He notes some people report headaches after using red light therapy.
And Rahman says you might want to tread carefully if you're prone to melasma, a form of hyperpigmentation more common among people with skin of color. She says visible light can stimulate pigmentation, though the risk is higher with shorter wavelengths, like blue light, than the longer wavelengths of red light. "But overusing it can absolutely cause people with pigment disorders to actually worsen," Rahman says.
Bottom line
Red light therapy shows promise for many aspects of health, but the evidence for some uses is a lot stronger than others. And it's not magic.
"Just shining light on you is not going to make you superhuman in any way," Arany says. You still have to do all the other things conducive to good health – like eating right, exercising and getting enough sleep.
But if you're looking for a health boost from red light, and the idea of wading through the sea of devices leaves your head spinning, you could always just go outside in the morning or early evening, when the ratio of red light is more favorable.
"You're actually getting more of that red light in the morning, that's why you get that coloration of the sky," Ozog says.
"Drink your coffee," he says, "listen to the birds, get that morning light and start your day off right."
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