Red Light Therapy 101: What It Is, How It Works, and What It Can Do for You

Red Light Therapy 101: What It Is, How It Works, and What It Can Do for You

Red light therapy, also known as photobiomodulation (PBM) or low-level laser light therapy, has been gaining attention for its potential health benefits. More and more research has shown multiple applications of red light therapy including reducing inflammation and alleviating pain. It can help the skin by promoting collagen growth, reducing wrinkles, and treating acne. Additionally, it has been shown to help with recovery for athletes, promote mood and energy, aid in wound healing, and even help reverse alopecia. From skin rejuvenation to muscle recovery, this non-invasive treatment uses specific wavelengths of light to stimulate healing and improve cellular function. But what exactly is red light therapy, and how can it benefit you?

How It Works

At its core, red light therapy harnesses the natural healing power of light to stimulate biological processes and promote healing or tissue regeneration deep within our cells. The therapy can be administered using light panels, handheld devices, or light-emitting diodes (LEDs), making it easy to use at home or in clinical settings. It is similar to a tanning bed but without ultraviolet wavelengths or heat that can damage the skin.

Red light has the longest wavelength and lowest energy in the visible spectrum. This means it can travel farther and pass through more obstacles than other colors of light without heating or damaging the cells like ultraviolet sunlight would. Think of brake lights or stop lights. They’re colored red so that motorists can see vehicles and intersections far ahead—even through dense fog, snow, or rain. Red light therapy works similarly; it can pass through the thick layers of the skin to interact with the cells and tissues underneath.

Once red or near-infrared light passes through the skin, it reaches the mitochondria, it boosts the production of adenosine triphosphate (ATP), which is the primary energy source for cellular function and repair. Red light therapy can also penetrate deeper and benefit cells that are not commonly exposed to light during normal day-to-day activity.¹ With more ATP, cells can function more efficiently, leading to faster healing, improved circulation, and better overall health.

More specifically, red light therapy uses light wavelengths ranging from 600 to 1,100 nanometers to penetrate deeper into tissues without causing destructive heat.¹ Once inside the cell, red light energizes a specific portion of the mitochondria called the chromophore which drives the production of ATP or cellular energy.² Damaged cells have a buildup of nitric oxide that can act as a brake on this production of energy.³ This is partially why damaged or scarred cells take so long to heal; they can’t produce energy as well as a healthy cell. Red light therapy, however, can release this bound nitric oxide which not only kick-starts the process of producing energy in damaged cells but also accelerates energy production in healthy cells.

Red Light Therapy Benefits

Cells in the neurons, muscle, liver, kidneys, and other organs highly involved in metabolism all benefit from this boost to their mitochondria. With more energy, every kind of cell functions better. More energy equips the body to repair wounds, boost new cell growth, fight inflammation, stimulate collagen production, and more.

Skin benefits widely from red light therapy. The light stimulates collagen production by increasing cellular energy and activating fibroblasts—the cells responsible for producing collagen.⁴ Inflamed skin benefits from the procedure, because red light therapy can reduce harmful oxidative stress by reducing and reversing metalloproteinase activity—enzymes responsible for producing reactive oxygen species.⁵ This preserves existing collagen in the skin and reduces redness and discoloration from inflammation. The release of bound nitric oxygen from the mitochondria relaxes the capillaries near the skin leading to better blood flow and oxygen. Overall, red light therapy reduces the appearance of wrinkles and scars, improves discoloration, and heals acne and inflammation.

Athletes also can benefit from red light therapy. Multiple studies have shown how red light therapy helps to reduce inflammation, promote tissue repair, and alleviate pain. By boosting ATP production in the mitochondria, red light therapy provides muscles with more energy to speed up recovery, improve performance, and reduce soreness after a workout.⁶ Additionally, by improving blood circulation and reducing oxidative stress, red light therapy speeds up recovery, soothes aching joints, and accelerates muscle growth.⁷ This makes red light therapy a valuable tool for athletes or anyone experiencing muscle soreness, joint pain, or chronic conditions like arthritis.

Those with depression or brain fog can also benefit from red light therapy. It helps to reduce oxidative stress and increase blood flow in the brain. Exposing the head or the whole body to red light boosts serotonin and dopamine in the brain.⁸ Red light therapy also helps to regulate melatonin and cortisol for better sleep.⁹ By promoting sleep, lowering inflammation, and supporting overall brain health, red light therapy offers a compelling potential solution for depression or seasonal affective disorder.

For those struggling with hair loss, red light therapy offers a non-invasive solution. Currently, the only treatment for male pattern baldness or female hair loss involves drugs like finasteride and minoxidil or surgical hair transplants. These options can be costly, ineffective, or have severe side effects. On the other hand, red light therapy can stimulate hair follicles, promote circulation to the scalp, and encourage hair regrowth.^{10, 11}

Conclusion

Overall, red light therapy is an exciting, science-backed approach to improving skin health, relieving pain, boosting hair growth, and enhancing overall well-being. Red light therapy is generally considered safe with minimal side effects. Unlike ultraviolet light from the sun or tanning beds, it does not cause skin damage or increase cancer risk. It also can energize cells that regular daylight cannot. Whether you’re an athlete looking to recover faster, someone struggling with chronic pain, or just looking for a natural anti-aging solution, red light therapy could be a game-changer for you.

Written by Ira Van Matre, PharmD Candidate 2025
Edited by Lindsey Dalton, PharmD

References

1. Glass GE. Photobiomodulation: The Clinical Applications of Low-Level Light Therapy [published correction appears in Aesthet Surg J. 2022 Apr 12;42(5):566. doi: 10.1093/asj/sjab396.]. Aesthet Surg J. 2021;41(6):723-738. doi:10.1093/asj/sjab025
2. Passarella S, Karu T. Absorption of monochromatic and narrow band radiation in the visible and near IR by both mitochondrial and non-mitochondrial photoacceptors results in photobiomodulation. J Photochem Photobiol B. 2014;140:344-358. doi:10.1016/j.jphotobiol.2014.07.021
3. Sarti P, Forte E, Mastronicola D, Giuffrè A, Arese M. Cytochrome c oxidase and nitric oxide in action: molecular mechanisms and pathophysiological implications. Biochim Biophys Acta. 2012;1817(4):610-619. doi:10.1016/j.bbabio.2011.09.002
4. Tatmatsu-Rocha JC, Ferraresi C, Hamblin MR, et al. Low-level laser therapy (904nm) can increase collagen and reduce oxidative and nitrosative stress in diabetic wounded mouse skin. J Photochem Photobiol B. 2016;164:96-102. doi:10.1016/j.jphotobiol.2016.09.017
5. Hamblin MR. Mechanisms and Mitochondrial Redox Signaling in Photobiomodulation. Photochem Photobiol. 2018;94(2):199-212. doi:10.1111/php.12864
6. González-Muñoz A, Cuevas-Cervera M, Pérez-Montilla JJ, et al. Efficacy of Photobiomodulation Therapy in the Treatment of Pain and Inflammation: A Literature Review. Healthcare (Basel). 2023;11(7):938. Published 2023 Mar 24. doi:10.3390/healthcare11070938
7. Luo WT, Lee CJ, Tam KW, Huang TW. Effects of Low-Level Laser Therapy on Muscular Performance and Soreness Recovery in Athletes: A Meta-analysis of Randomized Controlled Trials. Sports Health. 2022;14(5):687-693. doi:10.1177/19417381211039766
8. Wang L, Mao L, Huang Z, Switzer JA, Hess DC, Zhang Q. Photobiomodulation: shining a light on depression. Theranostics. 2025;15(2):362-383. Published 2025 Jan 1. doi:10.7150/thno.104502
9. Moro C, Valverde A, Dole M, et al. The effect of photobiomodulation on the brain during wakefulness and sleep. Front Neurosci. 2022;16:942536. Published 2022 Jul 28. doi:10.3389/fnins.2022.942536
10. Yoon JS, Ku WY, Lee JH, Ahn HC. Low-level light therapy using a helmet-type device for the treatment of androgenetic alopecia: A 16-week, multicenter, randomized, double-blind, sham device-controlled trial. Medicine (Baltimore). 2020;99(29):e21181. doi:10.1097/MD.0000000000021181
11. Mahe YF, Cheniti A, Tacheau C, et al. Low-Level Light Therapy Downregulates Scalp Inflammatory Biomarkers in Men With Androgenetic Alopecia and Boosts Minoxidil 2% to Bring a Sustainable Hair Regrowth Activity. Lasers Surg Med. 2021;53(9):1208-1219. doi:10.1002/lsm.23398