The Benefits of Red Light Therapy

There are not many wellness tools that have been studied in thousands of peer-reviewed clinical trials, used by NASA, adopted by professional sports teams, and yet remain largely unknown to the general public. Red light therapy — also called photobiomodulation, or low-level laser therapy — is one of them.

I first encountered red light therapy several years ago, initially skeptical of anything that sounded like it belonged in a spa brochure. But the more I read the research, the more I came to understand that this is not a wellness trend. It is a well-documented biological intervention with a clear mechanism of action and a remarkable breadth of clinical applications.

What Is Red Light Therapy?

Red light therapy involves exposing the body to low levels of red and near-infrared light — typically in the wavelength range of 630 to 850 nanometers. Unlike ultraviolet light, which damages skin cells, or the visible light from screens, which disrupts sleep, red and near-infrared wavelengths penetrate the skin and are absorbed by mitochondria — the energy-producing organelles inside our cells.

The primary mechanism is the stimulation of cytochrome c oxidase, an enzyme in the mitochondrial respiratory chain. When activated by red and near-infrared light, this enzyme increases the production of adenosine triphosphate (ATP) — the cellular energy currency that powers virtually every biological process in the body. More ATP means more energy available for cellular repair, regeneration, and function.

Red light therapy also reduces oxidative stress, modulates inflammation, increases circulation, and stimulates the production of collagen and other structural proteins. These effects ripple outward into a wide range of health outcomes.

What the Research Shows

Skin health and anti-aging. This is perhaps the most extensively studied application of red light therapy. Multiple randomized controlled trials have demonstrated that regular red light exposure increases collagen density, reduces fine lines and wrinkles, improves skin tone and texture, and accelerates wound healing. A 2014 study published in Photomedicine and Laser Surgery found significant improvements in skin complexion, skin feeling, and collagen density after 30 sessions of red light therapy. For those of us who spent years in the skincare industry, the science here is genuinely compelling.

Reduced inflammation and pain. Red light therapy has been shown to reduce both acute and chronic inflammation through multiple pathways, including modulation of pro-inflammatory cytokines and activation of anti-inflammatory mechanisms. Clinical trials have demonstrated benefit for conditions including rheumatoid arthritis, tendinopathy, neck pain, and low back pain. A 2009 meta-analysis in The Lancet found that low-level laser therapy reduced pain in chronic neck pain by a clinically meaningful margin compared to placebo.

Improved sleep. Near-infrared light exposure in the evening has been shown to increase melatonin production and improve sleep quality. A 2012 study of elite female basketball players found that 14 days of whole-body red light therapy significantly improved sleep quality and endurance performance compared to a placebo group. For those of us managing mood disorders — where sleep disruption is both a symptom and a trigger — this application is particularly relevant.

Mood and mental health. Emerging research suggests that red light therapy may have direct effects on brain function and mood. Near-infrared light penetrates the skull and is absorbed by neurons, increasing mitochondrial function in brain tissue. Studies have shown improvements in depression, anxiety, and cognitive function following transcranial near-infrared light therapy. A 2018 pilot study published in Behavioral and Brain Functions found significant reductions in depression and anxiety scores after just four weeks of near-infrared light treatment.

Muscle recovery and athletic performance. Red light therapy has been widely adopted in professional sports for its ability to accelerate muscle recovery, reduce delayed-onset muscle soreness, and improve performance. Multiple meta-analyses confirm that pre- and post-exercise red light therapy reduces markers of muscle damage and speeds recovery time.

Hair growth. Several randomized controlled trials have demonstrated that red light therapy stimulates hair follicle activity and increases hair density in both men and women with androgenetic alopecia. The FDA has cleared red light devices for this indication.

Thyroid function. A small but intriguing body of research suggests that red light therapy applied directly to the thyroid gland may improve thyroid function in patients with hypothyroidism, potentially reducing the need for medication. A 2013 randomized controlled trial published in Lasers in Surgery and Medicine found that patients receiving red light therapy required significantly lower doses of levothyroxine after treatment.

The Mental Health Connection

For those of us living with bipolar disorder, depression, or anxiety, the mood and sleep applications of red light therapy are worth taking seriously. Sleep disruption is one of the most reliable triggers for mood episodes — both depressive and manic — and anything that supports deeper, more restorative sleep is worth exploring.

I have incorporated red light therapy into my own morning routine, and I notice a genuine difference in my energy, mood, and skin over time. I am not suggesting it replaces medication, therapy, or the other pillars of mental health management. But as a complementary tool — one with a strong safety profile and a growing evidence base — it has earned a place in my daily practice.

How to Use Red Light Therapy

Red light therapy devices range from small handheld panels to full-body panels to professional clinical devices. For home use, a mid-sized panel that covers the face and torso is a practical starting point. Key parameters to look for:

• Wavelengths of 630–660 nm (red) and 810–850 nm (near-infrared). These are the most studied and clinically validated ranges. Devices that combine both wavelengths offer broader benefits.
• Irradiance of at least 50–100 mW/cm². This is the power density delivered to the skin. Too low and the dose is insufficient; too high and sessions need to be very brief. Most quality home panels fall in a useful range.
• Session length of 10–20 minutes per area. Most research protocols use sessions in this range, typically once daily or several times per week.
• Consistency over time. Like most biological interventions, red light therapy works cumulatively. Benefits build over weeks and months of regular use.

Red light therapy is generally very safe. The main precautions are to avoid looking directly into the light (use eye protection), to be cautious if you are taking photosensitizing medications, and to start with shorter sessions if you have very sensitive skin. It is not recommended over active cancer sites.

A Note on Quality

The red light therapy market has exploded in recent years, and not all devices are created equal. Many inexpensive panels deliver insufficient irradiance or use suboptimal wavelengths. I recommend researching devices that publish their irradiance measurements at specific distances, use medical-grade LEDs, and have third-party testing. This is one area where investing in quality makes a real difference in outcomes.

The research is clear, the mechanism is understood, and the safety profile is excellent. If you are looking for a wellness tool that works at the cellular level — supporting skin, sleep, mood, inflammation, and recovery simultaneously — red light therapy is one of the most evidence-backed options available to you.

Start with ten minutes in the morning. Give it a month. Pay attention to how you feel.

With love, Liz