It's classified as an alternative therapy,
Red light therapy (RLT), also known as photobiomodulation, low-level laser therapy, or low-power laser therapy, is a noninvasive treatment that uses low levels of red and near-infrared light to stimulate cellular function and promote healing.
It is thought to work by targeting mitochondria, the energy-producing structures within cells, increasing their production of ATP (adenosine triphosphate), which enhances cell repair, growth, and function.
This process may improve skin health, reduce inflammation, and alleviate pain.

The therapy is used for a variety of conditions. For skin health, it may help reduce wrinkles, fine lines, loose skin, and signs of sun damage by stimulating collagen and elastin production, improving skin elasticity and texture.
It is also used for acne, where it reduces inflammation and may improve acne lesions without destroying skin cells, unlike some other light therapies.
For hair loss, particularly androgenic alopecia, research suggests RLT can promote hair regrowth and increase hair thickness and length, potentially being as effective as topical treatments like minoxidil.
In pain management, RLT shows promise for reducing pain and inflammation associated with conditions like fibromyalgia, knee osteoarthritis, non-specific low back pain, and temporomandibular dysfunction (TMD).
It may also help with rheumatoid arthritis by reducing pain and morning stiffness, though evidence for other forms of arthritis like osteoarthritis is less clear.

Emerging research indicates potential benefits for cognitive function in individuals with dementia. Early studies have shown improvements in memory, sleep, and mood after regular transcranial and intranasal red light therapy, with some trials using specific wavelengths like 810 nm and 1070 nm combined with pulsing frequencies (e.g., 10 Hz or 40 Hz) to modulate brain waves.
Red light therapy is also being investigated for its role in wound healing, tissue repair, and reducing side effects from cancer treatments.

Red light therapy devices come in various forms, including masks for the face, panels for targeted areas, beds for full-body treatment, wands for small areas, and helmets or caps for the head.
Near-infrared light penetrates deeper into the body than red light, making it more effective for muscle recovery, joint pain, and deeper tissue healing.
While home devices are available, professional treatments using more powerful equipment may be more effective.
The FDA has cleared several devices for specific uses, such as treating aging skin and hair regrowth, but it's important to note that "FDA cleared" means the device is considered safe and equivalent to others on the market, not that it has been proven effective for the claimed benefits.

The therapy is generally considered safe with minimal side effects when used correctly. It does not use harmful UV rays and there is no evidence it causes cancer.
However, potential risks include eye damage, so protective goggles are recommended, especially during facial or head treatments.
Some individuals, particularly those with darker skin tones, may be more sensitive to red light and could experience hyperpigmentation.
Overuse or improper dosing—such as using a device for too long or at the wrong distance—can lead to burns or blisters.
Consistent use is typically required to see results, with most people using treatments two to five times per week for 10–20 minutes per session, though optimal protocols are still being researched.

Despite promising results, more large-scale, controlled human studies are needed to fully confirm the effectiveness of red light therapy for many conditions.
The quality and effectiveness of devices vary significantly, and consumers should look for reputable brands and devices that have been tested for proper wavelength and irradiance (fluence) to ensure they deliver a therapeutic dose.