Glow or Gimmick?: The Science of Red Light Therapy

Red Light Therapy - underpowered devices, overblown promises

Red light therapy, also called photobiomodulation, exposes people to low levels of red laser light, usually aimed at a specific body part, often the face or head. Typically, wavelengths used are 630-660 nanometers for red light and 810-850 nanometers for near-infrared. 

Red light therapy has legitimate biological potential, but the consumer market is a "Wild West." Wellness influencers claim it boosts collagen production, reduces inflammation, stimulates hair growth, improves mood, enhances circulation, improves sleep, reduces joint pain and stiffness, and more. It’s become the standard “it does everything!” kind of wellness product. You can find masks, pads, mats, belts, bags, helmets, and more.

For beauty applications, the main claims hinge on skin appearance and hair growth. In skin care, red light therapy is often described with phrases like “anti-aging,” “skin rejuvenation,” and “reclaiming youth.” More specifically, claims of reducing the appearance of fine lines and wrinkles, improving tone and texture, and making scars less visible.

What Does The Science Say?

There is evidence that red light therapy seems to have some impact on skin repair and hair regrowth. Theoretically, red light therapy enhances adenosine triphosphate (ATP) production in cells by activating cytochrome c oxidase, one of the components that creates energy in our mitochondria, our body’s “Energizer bunnies.” This can help repair skin and boost new cell growth. However, there is some conflicting evidence, especially around skin repair. For example, even in the studies that do find an effect, how much remains a question.

While we’ve got some evidence that it is beneficial for those two specific scenarios, it’s a slippery slope from there to “it works for everything!”  Be skeptical of the bold claims you’re likely seeing on social media for anything outside of these areas. For example, claims of its effectiveness for weight loss are overblown. The studies that are cited are small, short-duration, product-sponsored, and use inappropriate outcomes for fat loss. It’s very easy to sell a product. It’s very hard to understand if a product is worth buying.

At-Home Devices

If you’re looking for a beauty regimen that is backed by some sound science to reduce the appearance of fine lines and wrinkles, you could do worse than red light therapy. However, it requires regular treatments with the best devices found in dermatologists’ offices and less effective at-home options. 

“Since red light devices come in a variety of shapes and sizes, have different potencies and prescribed time of use, as well as extreme variation in costs, measuring their comparative effectiveness can be like comparing apples with oranges.”

--Hanae Armitage, Stanford Medicine Insights

What’s often missing from at-home devices is proper power density. If the light isn't sufficiently powerful, it won't penetrate the skin deeply enough to do anything, regardless of how long you wear the mask. Conversely, in red light therapy, more is not always better; you also don’t want the light to be too powerful. 

There is a "sweet spot" of energy; too little does nothing, but too much can actually negate the benefits. This is why it’s important to have some professional oversight in some capacity - for an at-home device, it may be difficult to tell an effective dose from too much or too little. Checking in with a dermatologist is the best course of action if you want to pursue at-home red light therapy, especially with the device you wish to use. 

If you do invest in a red light therapy product for at-home use, it should be:

• FDA-cleared, without claims to “cure” systemic diseases or promote rapid weight loss.
• Provide specific data on its irradiance and wavelength, not its “total wattage.”
• Come with a clear set of safety instructions regarding eye protection
• Be easy to clean

And keep in mind that “FDA cleared” is not the same as “FDA approved.” A product that has been cleared is substantially equivalent to another device that has been deemed safe and is already on the market. “FDA approved” applies to a specific medical benefit in using that device or product (medication)..

“Generally, the FDA “clears” moderate-risk medical devices for marketing once it has been demonstrated that the device is substantially equivalent to a legally marketed predicate device that does not require premarket approval.  

- FDA, Is It Really FDA Approved?”

Make sure you discuss with your dermatologist, who is familiar with your medical history and needs, before investing in any red light therapy products or starting a regimen. While red light therapy is generally safe, those with melasma (e.g., increased skin pigmentation) or on photosensitizing medications (e.g., tetracycline, St. John’s Wort) should consult their physician before use. 

“Reassuringly, red light therapy appears safe when used appropriately and carefully. However, the long-term risks are less well understood. High costs is an expected side effect, with potentially substantial costs.”

- Scott Gavura, Science Based Medicine

Red light therapy is not a miracle cure-all, but it’s not a total scam either. In controlled clinical settings, it may offer modest benefits for specific uses like skin repair and hair regrowth. The real danger comes from the wellness industry’s habit of turning “some evidence” into “life-changing transformation,” especially when selling expensive at-home devices that may deliver little more than a red glow.

Red light therapy is a tool that requires skepticism and a professional’s input and oversight. Red light therapy is generally safe, but it does carry a risk of wasting money, chasing inflated promises, or delaying proven treatments in favor of a trendy gadget. The light may be soothing — but the hype surrounding it should set off alarms brighter than any LED mask.