Questions about light therapy and skin? Check out these frequently asked questions about LED light therapy as a skincare product and simple, at-home treatment for skin conditions.
Q: What is light therapy for skin?
A: Light therapy (also known as LED therapy or phototherapy) is a quick, simple, and safe way to treat skin and skin conditions like acne, cold sores, canker sores, and genital sores. Light therapy devices isolate specific wavelengths of light (usually blue and/or red light) and shine them on the skin and cells, ideally every day. This has been shown in clinical research to improve blood flow, reduce inflammation, and aid in skin rejuvenation and healing. [1,2]
Light therapy with blue and red wavelengths is a popular acne treatment in professional settings with dermatologists and estheticians.  Red light therapy is used to treat and heal skin conditions like canker sores. There are many at-home devices designed for light therapy spot treatments for specific conditions. Two examples are the Luminance RED Lip Sore Treatment Device for cold sores and the reVive acne treatment devices.
Check out this article for a general overview of what light therapy is and how it works.
Read this article for a more specific look at what light therapy can do for skin and skin conditions.
Q: How does light therapy work for acne?
A: Most devices use either blue light therapy, red light therapy, or a combination of both blue and red wavelengths for acne spot treatments. Blue light therapy is used against acne because wavelengths of blue light have an antimicrobial effect, killing bacteria on the skin that gathers in pores and oil glands and causes acne breakouts.  Red light therapy has an anti-inflammatory effect on the skin and promotes the healing of skin and acne scars. [1,2,4]
While blue light kills acne-causing bacteria on the surface, red light works below the surface and in the cells, helping to repair damaged tissues and rejuvenate the skin from within. Research is showing that light therapy may be most effective for acne when red and blue light therapy are used together. [5,6,7,8,9]
Q: What is light therapy for psoriasis?
A: Light therapy with red wavelengths is sometimes used to treat the symptoms of psoriasis. Shining light on psoriasis spots can reduce itchiness and inflammation, as shown in clinical research (summarized below). There is no cure for psoriasis, so as with most chronic conditions, management of symptoms is central to treatment.
Q: How effective is light therapy for psoriasis?
A: Light therapy treatments can have a therapeutic effect on psoriasis, as shown in recent clinical research. A 2010 study treated patients with chronic psoriasis, which in most cases had proven resistant to conventional treatments. Researchers treated patients with red light therapy for a four to five week period with follow-ups, and found significant improvements in psoriasis symptoms.
Patients had a 60% to 100% clearance rate with recalcitrant psoriasis. Red light therapy reduced the skin inflammation of these psoriasis patients, and researchers concluded that “satisfaction was universally very high” among the psoriasis patients treated with red light. 
Another double-blind, randomized study assessed 20 patients with psoriasis. By monitoring two psoriatic plaques on each patient, one treated and one untreated, researchers were able to determine that red light therapy improved psoriasis by reducing redness, hardening, and scaling of the skin. 
Q: What is light therapy for eczema? Does light therapy work for eczema?
A: Light therapy treatments with red wavelengths are used to treat the symptoms of eczema. Recent clinical research has shown positive results for reducing the itching and inflammation caused by eczema.
In one trial, researchers followed 81 patients for nearly a year, measuring how their symptoms progressed with regular light treatments. The researchers evaluated eczema rashes before, during, and after patients received red light therapy treatments.
Participants received just a single, two-minute red light therapy session per week. Even with such short treatments, they saw considerable improvements in common eczema symptoms, including a reduction in bumps, flaking skin, redness, and pimples.  The researchers concluded that red light treatments “may become the new therapy of choice” for common eczema. 
Q: How does light therapy work for skin?
A: For skin benefits, blue light therapy works by killing bacteria on the surface of the skin. Red light therapy reduces inflammation by increasing blood flow to damaged tissues. [1,2]
Red light therapy also works by helping skin cells produce energy. The mitochondria in our cells absorb wavelengths of red light and use it to make energy and power the body with adenosine triphosphate (ATP). [13,14] Daily light therapy treatments ensure that skin cells get an abundance of red light and produce energy efficiently.
Q: Which wavelengths and colors are used for light therapy skin benefits?
A: Most light therapy devices used for skincare shine blue light, red light, or a combination of both. Blue light therapy is mostly used as an acne treatment because blue light kills bacteria on the skin that leads to acne. Red light therapy is also used to treat acne, wrinkles, wounds, cold sores, and other skin conditions because of its anti-inflammatory and healing effects on the skin.
Check out this article to learn more about the different colors and wavelengths used in light therapy.
Q: How often should I use red light therapy?
A: It’s best to get your light therapy treatments every day, or at least five times per week. Consistency is crucial for effective light therapy. One treatment may produce a short-term benefit, but regular light therapy is needed to see longer-lasting effects.
For people treating skin conditions, it’s recommended to do two to three short light therapy sessions per day as soon as you feel symptoms emerging. The more regularly you use light therapy on your skin, the better your results will be.
Check out this post for more details on how often you should use light therapy.
Q: How long does it take for light therapy to work?
A: For skin health benefits, use light therapy regularly for at least a few weeks to start seeing results. For skin conditions and outbreaks, a few days of LED treatments can make a difference.
Q: Which skin conditions can light therapy heal and treat?
Light therapy is a safe, effective treatment for acne, psoriasis and eczema, lip sores and cold sores caused by the herpes simplex virus, mouth sores, canker sores, and wounds.
Q: Should I use blue light, red light, or both for acne treatments?
A: Both blue light therapy and red light therapy have positive effects on acne and skin. Research is showing that combination red and blue light therapy may be the most effective for acne treatments. [5,6,7,8,9]
Q: Can you use light therapy for cold sores?
A: Yes, light therapy is used for cold sores. Numerous peer-reviewed clinical trials have shown light therapy treatments can improve healing and limit outbreaks of cold sores, or herpes labialis. Check out this post on cold sores and light therapy to learn more.
Q: Can you use light therapy for canker sores?
A: Yes, clinical research has shown that red light wavelengths can reduce pain and improve healing of canker sores. Check out this article for more details on canker sores and light therapy.
Q: Can you use light therapy for genital sores?
Yes, light therapy is used to treat genital sores from genital herpes and other conditions. This article has more details on light therapy treatments for genital sores.
Q: Does light therapy work for burns?
A: Yes, light therapy treatments with red and near-infrared (NIR) wavelengths have proven to be a safe and effective treatment for the healing of burns.
In 2016, researchers conducted the first human trial on red light treatments and third-degree burns. In the study, light therapy was combined with split-thickness skin grafting (the standard for third-degree burn treatment).  Doctors used red and NIR light treatments before and after skin grafts, which helped every patient in the study recover from their serious burns. The researchers concluded, “The results of this study showed complete healing in the last 8 weeks for all patients who were candidates for amputation.” 
This article has more details about light therapy for burns and burn healing.
Q: Does light therapy work for wounds, cuts, and skin injuries?
A: Yes, light therapy is a noninvasive way to improve healing for wounds and injuries, including surgical incisions. Clinical studies on wound healing show that red light treatments can help the body produce new blood vessels and tissues at higher rates, leading to better healing outcomes and less pain. [16,17,18]
This article has more details on LED treatments for wounds, cuts, and injuries.
Q: Can red light therapy diminish the appearance of scars?
A: Yes, clinical research is showing very positive results for LED light therapy treatments on scars. A number of clinical studies have shown that light treatments with red light can help heal scar tissue and even diminish the appearance of scars over time.
One peer-reviewed study of burn scars found that patients treated with wavelengths of red light showed twice as much decrease in visible scarring as people who didn’t do light therapy sessions. None of the patients reported any negative effects from the light treatments. 
Another peer-reviewed study looked at hypertrophic (raised) scars on children. Researchers treated one half of each scar with light (in addition to the usual topical treatment) for three months. They then compared this half to the half of the scar treated only with the topical treatment. They found that the scar areas treated with light showed significant improvement, and concluded that light treatments are safe and effective for raised scars. 
Q: Is light therapy safe for skin? What are the side effects and risks of LED light therapy for skin?
A: Light therapy has been widely studied and tested in peer-reviewed skin health research. The consensus is that light therapy treatments are safe, well-tolerated, and produce very few side effects.
Dermatology researchers from Harvard Medical School conducted a review of red light therapy in 2013 and praised its “noninvasive nature and almost complete absence of side effects.”  That said, you should contact a trusted healthcare provider to discuss light therapy if you’re taking medications or if you have light or photosensitivity issues.
If you have more questions about light therapy, check out these general light therapy FAQs.
Sources and References:
 Avci P, Gupta A, et al. Low-level laser (light) therapy (LLLT) in skin: stimulating, healing, restoring. Seminars in Cutaneous Medicine and Surgery. Mar 2013; 32(1): 41-52.
 Hamblin M. “Mechanisms and applications of the anti-inflammatory effects of photobiomodulation.” AIMS Biophys. 2017.
 Jagdeo J, Austin E, Mamalis A, Wong C, Ho D, Siegel DM. Light-emitting diodes in dermatology: A systematic review of randomized controlled trials. Lasers Surg Med. 2018 Jan 22; 50(6): 613–28.
 Mayo Clinic. Acne Diagnosis and Treatment.
 Li WH, Fassih A, Binner C, Parsa R, Southall MD. Low-level red LED light inhibits hyperkeratinization and inflammation induced by unsaturated fatty acid in an in vitro model mimicking acne. Lasers Surg Med. 2018 Feb; 50(2): 158-165.
 Kwon HH, Lee JB, Yoon JY, Park SY, Ryu HH, Park BM, Kim YJ, Suh DH. The clinical and histological effect of home-use, combination blue-red LED phototherapy for mild-to-moderate acne vulgaris in Korean patients: a double-blind, randomized controlled trial. Br J Dermatol. 2013 May; 168(5): 1088-94.
 Sadick NS. Handheld LED array device in the treatment of acne vulgaris. J Drugs Dermatol. 2008 Apr; 7(4): 347-50.
 Alba MN, Gerenutti M, Yoshida VM, Grotto D. Clinical comparison of salicylic acid peel and LED-Laser phototherapy for the treatment of Acne vulgaris in teenagers. J Cosmet Laser Ther. 2017 Feb; 19(1): 49-53.
 Jung YR, Kim SJ, Sohn KC, Lee Y, Seo YJ, Lee YH, Whang KU, Kim CD, Lee JH, Im M. Regulation of lipid production by light-emitting diodes in human sebocytes. Arch Dermatol Res. 2015 Apr; 307(3): 265-73.
 Ablon G. Combination 830-nm and 633-nm light-emitting diode phototherapy shows promise in the treatment of recalcitrant psoriasis: preliminary findings. Photomedicine and Laser Surgery. 2010 Feb.
 Kleinpenning MM, Otero ME, et al. Efficacy of blue light vs. red light in the treatment of psoriasis: a double-blind, randomized comparative study. Journal of the European Academy of Dermatology and Venereology. 2012 Feb.
 Morita H, Kohno J. et al. Clinical Application of GaAlAs 830 nm Diode Laser for Atopic Dermatitis. Laser Therapy. 1993 vol 5.
 Karu T. Primary and Secondary Mechanisms of Action of Visible to Near-IR Radiation on Cells. Journal of Photochemistry Photobiology. 1999 Mar.
 Ferraresi C, Kaippert B, et al. Low-level Laser (Light) Therapy Increases Mitochondrial Membrane Potential and ATP Synthesis in C2C12 Myotubes with a Peak Response at 3-6 h. Photochemistry and Photobiology. 2015 Mar.
 Dahmardehei M, Kazemikhoo N, et al. Effects of low level laser therapy on the prognosis of split-thickness skin graft in type 3 burn of diabetic patients: a case series. Lasers in Medical Science. 2016 Apr.
 Gál P, Stausholm MB, et al. Should open excisions and sutured incisions be treated differently? A review and meta-analysis of animal wound models following low-level laser therapy. Lasers in Medical Science. 2018 Aug.
 da Silva Melo, Alves LP, et al. LED phototherapy in full-thickness burns induced by CO2 laser in rats skin. Lasers in Medical Science. 2018 Sep.
 Silveira PC, Ferreira KB, et al. Effect of Low-Power Laser (LPL) and Light-Emitting Diode (LED) on Inflammatory Response in Burn Wound Healing. Inflammation. 2016 Aug.
 Gaida K, Koller R, et al. Low Level Laser Therapy–a conservative approach to the burn scar? Burns : journal of the International Society for Burn Injuries. 2004 June.
 Alsharnoubi J, Shoukry K, et al. Evaluation of scars in children after treatment with low-level laser. Lasers in Medical Science.