Red light therapy: benefits, uses, and side effects

Yael Cooperman, MD - Contributor Avatar

Reviewed by Yael Cooperman, MD, Ro, 

Written by Linnea Zielinski 

Yael Cooperman, MD - Contributor Avatar

Reviewed by Yael Cooperman, MD, Ro, 

Written by Linnea Zielinski 

last updated: Aug 13, 2021

4 min read

Once a fringe health practice, red light therapy is now a prime offering at wellness spas and a common gym membership add-on. 

In the promotional materials for these services, you’ll see enticing claims about the benefits of red light therapy, from faster wound healing to increased hair growth. But before you drop money on this treatment, you should know that it isn’t the most effective treatment available for many of the conditions it claims to treat.


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What is red light therapy?

Red light therapy is a form of light therapy that goes by several different names, including low-level laser therapy (LLLT), low-power laser therapy, and photobiomodulation. The tool used for red light therapy depends on what you’re trying to treat.

Red light therapy can be performed with tanning-bed-like devices filled with light-emitting diodes (LEDs) or even helmets used for targeted treatment areas, like your scalp. Estheticians and dermatologists offer in-office treatments and the internet is filled with at-home versions you can try. But not all devices are created equal. 

How does it work?

If you’ve heard of laser therapies before, you probably heard about the lasers used by dermatologists to strategically damage skin tissue and promote regeneration of collagen, alleviating fine lines. This is different. Red light therapies aren’t hot, which is why it’s sometimes referred to as a “cold laser” (Chung, 2012)

Scientists have found that exposure to certain types of red light prompts our mitochondria––which are essentially the battery packs of our cells––to create more energy. Red light therapy is also said to increase blood circulation, activate stem cells, and spur collagen production (Avci, 2013).

What is red light therapy used for?

Red light therapy is a standard tool among dermatologists. They use this type of light therapy to address things like age spots, fine lines, wrinkles, acne, sun damage, scars, and hair loss. It’s also used to treat conditions like psoriasis and vitiligo (Avci, 2013).

Preventing and combating wrinkles is one of the best-known benefits of red light therapy. It’s important to keep in mind that many at-home products claim to replicate the anti-aging clinical effects of clinic-based treatments, but the evidence is lacking. 

Researchers believe red light wavelengths can stimulate collagen production by increasing the production of fibroblasts, which are the cells in your body responsible for producing that collagen and building connective tissue.

Cold laser therapy is also sometimes used to speed the healing of cold sores, decrease inflammation, and ease joint and muscle pain (Elvir-Lazo, 2020).

Is red light therapy effective?

Despite 40 years of studying laser therapies, we still don’t fully understand its effects on the body. More research is needed in many areas, although studies have found red light therapy treatments to be effective for certain things including :

  • Androgenic alopecia: Twenty-four weeks of red light therapy improved hair coverage and thickness compared to placebo treatment in people with androgenic alopecia (also called male or female pattern baldness), one study found. Participants were treated three times a week for 30 minutes (Mai-Yi Fan, 2018).

  • Cold sores: Red light therapy may slightly speed the healing time of cold sores. Patients treated with red light healed an average of two days faster than those given sham treatment, one study found (Dougal, 2013).

  • Wrinkles: Studies support the use of light treatments to decrease the appearance of wrinkles, but red light may not have the edge over other therapies. One study found that red and white dermatology lights improved the look of wrinkles around the eyes (Nam, 2017).

LLLT may also effectively diminish the look of several skin concerns in combination with other treatments. Researchers who used a mixture of 5-aminolevulinic acid (ALA) and hyaluronic acid activated by red light found significant improvements in fine lines, sun spots, pore size, and skin texture of study participants (Huang, 2019).

At-home devices vs clinical therapy

At-home red light therapy devices aren’t as strong as the ones you might be offered in a clinical setting, and there’s no getting around that for now. 

That means clinical treatments are more effective, but regular use of at-home devices can still add up to visible changes. But while you may need fewer professional treatments to see results, you’ll pay for each of these appointments. If you buy a quality at-home device that you’ll continue to use, that’s a one-time cost.

If you’re looking for an at-home device, you’ll need to choose between laser diodes and light-emitting diodes (LEDs). One meta-analysis of research comparing at-home treatments to professional therapies found that the studies supported laser diode devices for hair loss and LEDs for acne (Cohen, 2021).

Potential side effects may also affect your decision. Laser treatments can cause burns and skin damage but LED light therapy cannot. You may also want to opt for an FDA-approved device that has been evaluated for efficacy and safety.

Make sure you use these devices as directed and wear tanning goggles if indicated and avoid the eye area to prevent eye damage.

Treatment alternatives

Red light therapy isn’t your only option for treating wrinkles or hair loss.

Medications like finasteride (brand name Propecia) and minoxidil (brand name Rogaine) can treat androgenic alopecia by promoting hair growth (Adil, 2017).

Finasteride is a prescription medication taken as a pill you swallow daily, while minoxidil is available over-the-counter as a topical liquid or foam you apply right to your scalp. If those options appeal to you more than light therapy, talk to a healthcare professional about the best form and strength for you.

When it comes to fine lines and wrinkles, retinoids are a powerful option. These topical treatments increase skin cell turnover, or how quickly your body makes new layers and sheds old ones. They also boost your skin cells' ability to replenish their collagen, supporting the underlying structure that keeps skin plump and smooth (Mukherjee, 2006).

Red light therapy is a type of light treatment that helps with hair loss, fine lines, and wound healing. Professional treatments are more potent than at-home devices but may be less convenient or more expensive. These treatments have few side effects and no downtime, but they’re not the only options for addressing these conditions.


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

August 13, 2021

Written by

Linnea Zielinski

Fact checked by

Yael Cooperman, MD

About the medical reviewer

Yael Cooperman is a physician and works as a Senior Manager, Medical Content & Education at Ro.