Red Light Therapy

by Ashley Hamer Pritchard
June 9, 2026

This episode was sponsored by Lisa Baby

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Walk into an upscale gym, swing by a spa, or scroll social media these days and you’re bound to find it: panels of red and near-infrared LEDs in everything from handheld face wands to full-body setups the size of a closet door. Proponents say red light therapy can reduce wrinkles, regrow hair, accelerate muscle recovery, improve sleep, treat depression, and slow cognitive decline. Some even claim it can help you lose weight or cure erectile dysfunction. Devices range from $30 LED wands on Amazon to $1,500 skincare masks and hair-regrowth helmets to clinical sessions billed at $200 a pop.

On the surface, it looks like a classic wellness grift. But red light therapy is unique in the world of health panaceas: it has serious research funding from bodies like the NIH, and a consensus review signed by more than 20 specialists concluded it works for a number of specific conditions. So what’s actually going on? The answer requires separating a real clinical tool from the industry that’s colonized it.

What Red Light Therapy Actually Is

You may have heard this called low-level laser therapy, photobiomodulation, near-infrared therapy, or just red-light therapy. These terms refer to overlapping but not identical things, and that inconsistency happens to be pretty convenient — the manufacturers benefit when consumers are confused. For our purposes, we’re talking about the same basic phenomenon: red to near-infrared wavelengths of light that are long enough to pass through clothing and into human tissue, to the point they can reach living cells beneath the skin’s surface.

The red wavelengths with the greatest evidence for biological effects happen to match the ones best absorbed by cytochrome c oxidase, an important enzyme in mitochondria. There’s evidence to suggest that this interaction nudges mitochondria toward producing ATP, the molecule cells use to store and transfer energy. That leads to things like improved blood flow and better regulation of inflammation and oxidative stress.

And it does all of this safely: while UV light can damage DNA and lead to skin cancer, red light leaves DNA unscathed.

Where It Came From

The biological benefits of red light were discovered in the late 1960s by a Hungarian scientist named Endre Mester. He shined low-level laser light on the shaved skin of mice to see if it would trigger skin cancer. It didn’t, but it did something else: it made their fur grow back faster.

Mester later found that the lasers also helped with wound healing. Soon, other scientists joined the burgeoning field of low-level laser therapy and made their own discoveries. They found you could use near-infrared light, too, and that LEDs worked just as well as lasers.

But this therapy really got going in the 1990s with NASA, when researchers were using LEDs in a narrow wavelength of red light to help plants grow in space. As the story goes, the scientists noticed that small cuts on their hands healed surprisingly quickly under the lights, and NASA soon began investigating the effects of these LEDs in medical applications.

Still, the field stayed limited to niche clinical uses until the mid-2010s, when it got picked up by the biohacking and wellness communities. But the real mainstream explosion came in early 2024, when social media celebrities started featuring LED masks in TikTok content. The hashtag “red LED light therapy” surpassed 70 million views by February of that year.

At this point, what was previously a clinical tool became a lifestyle product — one whose evidence base didn’t really matter to most of the people buying.

What the Evidence Actually Supports

But just because consumer devices on social media are suspect doesn’t mean red-light therapy is bogus. There’s plenty of evidence for its effectiveness — just for a limited set of conditions, at specific parameters, in clinical settings.

The strongest evidence is for hair loss — which was the application that started the field in the first place, in those little Hungarian mice. Several well-controlled studies have found that low-level laser therapy in a specific range, usually from a helmet or comb, over 16 to 26 weeks, is associated with significant improvement in hair density. This works because when the red light stimulates mitochondria in hair follicles, it triggers dormant ones to re-enter the active growth phase, and lengthens that phase in follicles that are already growing.

Red light therapy has also shown to be effective in wound healing. A 2025 expert consensus review found there’s enough evidence to call the therapy safe and effective for healing several types of ulcers and radiation dermatitis. It’s also now recommended in clinical guidelines for preventing and treating mouth ulcers caused by cancer therapy. Dermatologists have been using it in conjunction with topical drugs to kill early skin cancer cells, too, though this uses a slightly different mechanism.

There’s also strong evidence for treatment of peripheral neuropathy. And in November 2024, the FDA authorized a red-light therapy device — the first of its kind — to treat age-related macular degeneration.

What about those red-light masks for improving your appearance? A 2024 review of 59 dermatology studies found the strongest evidence for red light in treating acne. The evidence for its ability to treat wrinkles and rejuvenate the skin was weaker — the results were inconsistent, and many studies weren’t well controlled.

Finally, there’s a bevy of other conditions with weak or nonexistent evidence. Think athletic recovery, sleep support, chronic pain, erectile dysfunction, weight loss, and cancer. There are some intriguing NIH studies looking at its use in treating Alzheimer’s and cognitive decline, but those are still in the early stage.

Why the Evidence Isn’t Cut and Dry

Studies into red-light therapy generally run into three big problems. One is that “red light therapy” isn’t just one thing: wavelengths, power levels, total energy dose, session length, distance from the skin, and length of treatment can all vary. There’s no standardized protocol that all studies need to follow. A positive result in one study doesn’t automatically transfer to all devices or applications — a successful trial using a laser comb at a particular wavelength doesn’t mean an LED panel with a different wavelength works just as well.

The second problem is old-fashioned bias: The field heavily relies on industry-funded studies with small numbers of volunteers, which is a recipe for inflated effect sizes.

The deepest issue, though, is the fact that when it comes to red-light therapy, a sham control may not exist. Control groups that don’t receive red-light therapy are essential for determining whether there’s a real effect, and volunteers can’t know which group they’re in so they don’t skew the results. So researchers traditionally use dim red light as a placebo: it looks the same, but shouldn’t have any effect.

But several studies have seen significant effects from the dim red light they used as a control. One study looking at skin rejuvenation didn’t use a control at all for this reason, saying, quote “The therapy cannot be blinded, and a sham light source without any effect most likely does not exist.” End quote.

If the sham is also biologically active, the studies may actually be understating how effective red light therapy is. But they also can’t rule out that both groups are responding to expectation rather than the actual light. Either way, we don’t have a clean answer.

The Consumer Market: Where It Gets Worse

But even if the clinical evidence for certain conditions was perfect, it would be for clinical devices operating at clinical parameters. An LED panel in your dermatologist’s office is not the same as an LED panel you bought on TikTok.

One way consumer-grade manufacturers will apply a veneer of authenticity is by advertising their devices as “FDA-cleared” or “FDA-approved.” These sound like they mean the same thing, but they don’t. FDA approval requires clinical trials proving safety and effectiveness — it’s time-consuming and expensive, and shows the manufacturer did the work. FDA clearance just requires showing a device is “substantially equivalent” to another device already on the market. It says nothing about whether it works for the claims made in the marketing copy.

On top of that, some manufacturers use “FDA-registered” or “FDA-certified,” which have essentially no regulatory meaning.

The biggest problem with consumer devices is power. A consumer-grade LED mask can deliver the exact same wavelength that was used in a successful study, but it probably won’t deliver the same amount of power — and there’s no way to know that from the packaging.

Manufacturers have hitched their wagons to a promising field of medical research and promised to give consumers the same effects they see in the studies — but often, the only effect consumers see is a lighter wallet.

Red Light Therapy: Real or Snake Oil?

It might seem outlandish to think you can shine a red light at your skin and achieve real biological effects. But the evidence is there, and it’s growing. Researchers understand the mechanism and have published real results. Especially for hair loss and certain wound and skin conditions, there’s good evidence — as long as you’re in a clinical setting with proper equipment and protocols.

But the version most people encounter? The $40 LED mask, the “anti-aging” red-light panel, the recovery sauna? That’s a different product making the same claims on a thinner evidence base. If you buy them, you won’t hurt yourself, but you will spend money on something that doesn’t work — and maybe even keep yourself from treatments that do work.

The question to ask isn’t “does red light therapy work?” It’s “does this specific device, at these parameters, for this specific condition, have evidence behind it?” Almost always, the answer is: probably not.

If you’re intrigued by the effects of red-light therapy you’ve heard about in this episode, though, there’s a completely free way to get some of its benefits: go outside. We’re spending more time indoors, and at the same time, our light sources are removing more and more red and near-infrared wavelengths in an effort to conserve energy.

Full-spectrum sunlight is good for you. Researchers have long assumed the health benefits of sun exposure were driven by vitamin D from UV light — but clinical trials of vitamin D supplements have repeatedly failed to replicate those benefits, which has led some researchers to look at other components of sunlight, including red and near-infrared wavelengths, as the active ingredient. That being said, wear your sunblock.

The wellness industry didn’t invent red-light therapy. It borrowed a clinical tool, inflated its claims, and sold it back to people who don’t have easy access to the research. It’s worth remembering that “science-backed” is a marketing phrase. The science itself is available, specific, and tells a much more limited story than the ads do.

By Ashley Hamer Pritchard