If your social media feed is full of glowing red face masks and crimson saunas, you're not alone. Lately, it seems like everyone is obsessed with red light therapy and hailing it for its various health benefits — from improving acne and wrinkles to stimulating hair growth and optimizing muscle recovery.
On TikTok, you'll find countless videos of influencers and celebrities touting trendy red light LED devices. Actor Lily Reinhart recently posted a video of herself using red light therapy for her alopecia.
As with many wellness trends, you may be wondering if red light therapy actually works or it's all hype. Does exposing the skin to red light actually help treat skin conditions, hair loss or improve exercise? Are red light spas and trendy gadgets worth it?
We spoke to experts about the science behind red light therapy, the potential uses and benefits, and risks to consider before trying it out.
What does red light therapy actually do?
Red light therapy exposes the skin to low levels of red or near-infrared light energy, Dr. Mary Stevenson, a dermatologist and skin cancer surgeon at NYU Langone Health, tells TODAY.com.
Generally, red light therapy uses wavelengths of visible red light between about 630 to 700 nanometers, which penetrate the skin where cells can absorb it, says Stevenson. "Many systems also include a small amount of infrared light — which is not visible on the spectrum of light — and penetrates the skin more deeply," says Stevenson. Near-infrared light has wavelengths from 700 nm to 1,000 nm.
The technology, which was legitimized through NASA experiments in the 1980s, and light sources used, have evolved over time. Today red light therapy typically uses LEDs (light-emitting diodes) and lasers to treat various medical conditions.
LED light therapy is often used for skin concerns or rejuvenation, and low-level laser therapy is used for pain relief and other musculoskeletal conditions, Dr. Dominic King, a sports medicine physician at the Cleveland Clinic, tells TODAY.com.
"Red light therapy works via process called photobiomodulation,” says Stevenson. "The energy emitted by LEDs (or lasers) is absorbed by chromophores in the skin, including the mitochondria — the powerhouse of the cell that generates its energy — and cytochrome C, a protein critical for the cellular respiration," says Stevenson.
In other words, red light is thought to increase energy production in cells so they can function more efficiently, the experts note, "including pathways that stimulate growth and those that limit inflammation," Stevenson adds.
Red light therapy devices
The red light is administered using various devices and machines, such as beds, panels, lamps, face masks, handheld wands and even helmets. These target areas ranging in size from a small area of skin to the full body. Depending on the application and use, red light therapy may be done in a medical office, a spa or at home.
An important distinction is that red light therapy does not use ultraviolet (UV) rays, Dr. Shari Lipner, a dermatologist at Weill Cornell Medicine, tells TODAY.com.
UV wavelengths are from 100 to 380 nanometers, which is lower than red light but higher in energy. "UV light can cause DNA damage and be harmful, so red light is actually safer," says Lipner.
Red light therapy is also different from phototherapy, which uses bright UVA or UVB light to treat conditions such as newborn jaundice or psoriasis, and is administered in medical settings, per the Cleveland Clinic.
Red light therapy benefits
There are many claims about the possible uses and benefits of red light therapy. According to the experts, the photomodulation process may act on a cellular level to help:
- Enhance cell growth
- Reduce inflammation
- Regenerate tissue
- Boost collagen and elastin
- Promote hair regrowth
“Depending on what condition we’re treating, it seems to have a slightly different mechanism of action,” says Lipner.
While research on the uses and benefits of red light therapy is promising, it's still emerging, the experts emphasize. However, red light therapy has shown potential for treating various conditions.
Red light therapy for skin conditions
Red light therapy is commonly used to treat a range of skin conditions and issues. The low-level red and near-infrared light is thought to penetrate the skin and help improve the appearance of:
- Acne
- Wrinkles
- Sun damage
- Scars
- Skin elasticity
- Facial texture
Red light therapy has been shown to promote the production of collagen and elastin by stimulating fibroblasts, which help build connective tissue, says Stevenson. Collagen provides support and structure, whereas elastin provides stretchiness in the skin, per the Cleveland Clinic.
It may also stimulate the production of growth factors, says Lipner, which help strengthen the skin barrier and rejuvenate skin, TODAY.com previously reported.
"There is good data on skin rejuvenation, and for that, we're talking about wrinkles, broken blood vessels, elasticity of the skin, moisture level, roughness and tightness," says Lipner.
In terms of acne, red light therapy's anti-inflammatory effects may help reduce the appearance of breakouts and redness. It may also lower sebum levels and destroy bacteria involved in acne, says Lipner. However, it often has to be done on a regular basis, as in multiple times a week for weeks to months.
Red light therapy is thought to speed up the wound-healing process by enhancing cell growth and tissue regeneration, says King. It may also help improve or prevent scar thickness when used with other treatments, says Lipner.
In dermatology offices, red light therapy is used in a process called photodynamic therapy, says Stevenson. "First, photosensitizing agents are applied to the skin and absorbed by pre-cancerous and sun-damaged cells, then red light is shined on the area ... which (destroys) the cells that have absorbed the agent," says Stevenson.
Red light therapy for hair loss
Red light therapy is commonly used as a treatment for hair loss in people with androgenetic alopecia, which causes pattern baldness in men and women, per the Cleveland Clinic.
The low-level red light may stimulate hair regrowth in several ways. "There is evidence that this light therapy prolongs the anagen phase (a period of active growth) of the hair cycle, and there's also evidence that it causes the release of growth factors from the cells that surround the hair follicle," Lipner explains.
A 2021 review of previous research found that low-level laser therapy represents a non-invasive, safe and potentially effective treatment option for androgenetic alopecia patients who do not respond to or tolerate standard treatment.
“I think it's a good adjunct ... for hair loss. Usually a topical or oral treatment is recommended by dermatologist, and red light therapy can be a helper," Lipner adds.
Red light therapy for exercise and recovery
Many claim red light therapy has benefits for exercise and swear by it as a pre- or post-workout routine.
The cellular effects of red light therapy are believed to reduce inflammation, relieve pain, and promote healing of wounds, muscles and nerves, says King.
A 2015 systematic review investigating the effects of red light therapy on exercise found that red light therapy shows promising results for improving performance and aiding muscle recovery when applied before physical activity, says King.
"There is an indication that the correct dosing can enhance performance and provide protective effects against muscle damage (and injury)," says King, but more research is needed. The evidence for exercise is promising, but not conclusive, King adds.
Does red light therapy work?
Red light therapy is relatively new and its potential applications and benefits are an ongoing area of research, the experts note. While it has shown to be promising for some conditions, many of the popular uses are not well-studied.
"Red light therapy shows intriguing potential, but until thorough scientific validation confirms its efficacy, we have to exercise caution in making claims about its ability to treat conditions," says King.
Effectiveness may also vary depending on the device, dosage and frequency of use. Many devices have not been approved by the U.S. Food and Drug Administration, but some are FDA-cleared.
Additionally, more research is needed to understand how red light therapy compares to standard, proven treatments. For skin health, "there are many other lasers and treatments that can be more effective and more efficient," Stevenson notes.
However, red light therapy may be helpful when used along with other treatments. “The main point is, whatever your condition or whatever you’re looking for, this shouldn’t be the No. 1 treatment that you go to,” says Lipner.
Leave it up to a doctor to help you decide what treatment is best for you, the experts note.
Red light therapy dangers and side effects
Red light therapy is non-invasive, non-toxic and generally safe when used as directed — but there are potential risks and downsides to consider, says King.
These include, but are not limited to:
- Tissue damage. "If used improperly, with excessive power or duration, it can cause burns or tissue damage," says King.
- Eye Damage. "Direct exposure to the eyes can be harmful, and protective eyewear is typically recommended during treatment," King adds.
- Adverse skin reactions
- Interactions with medications
- Inconsistent results
- Wasted money
Who should not use red light therapy?
Certain groups are at higher risk and should check with their doctor first or avoid red light therapy altogether, says King. These include:
- Pregnant people
- Children
- Cancer patients
- People with conditions that cause photosensitivity
- People taking medications that cause photosensitivity
- People with epilepsy
- People with thyroid disorders
Additionally, people with darker skin tones may be at higher risk of hyper- or hypopigmentation, says Lipner.
How to try red light therapy safely
If you're interested in red light therapy to treat a skin condition, "discuss it with your dermatologist and try an in-office treatment," says Stevenson. These are often more effective and safe.
If you choose to use a device at home, a dermatologist can also help you determine what dosage and frequency is best depending on what you're trying to treat, says Lipner.
Always follow the device instructions, and use it as directed. "Start with only a few minutes, working your way up to about 3 times a week," says Stevenson. If you experience pain, discomfort or any side effects, stop using the device.
Overall, red light therapy is a promising treatment for certain conditions but not a quick fix or a cure-all. No matter how trendy something is on social media, the experts encourage people to do their research and talk to their doctor.