Healthier, smoother skin thanks to the use of red light therapy

Red light therapy is an innovative tool that many people are using to treat a variety of different skin concerns. Although it is a newer form of therapy, the use of red light therapy to improve skin health and quality has become very popular in traditional skin care, helping people achieve their skin health goals.

People use red light therapy on the skin for a variety of conditions, including:

• Promoting wound healing
• Reducing Psoriasis Symptoms
• Improving melasma
• Reducing post-inflammatory hyperpigmentation
• Reducing wrinkles and lines
• Improving skin strength and elasticity
• Improving acne
• Improving scars and stretch marks
• Reducing age spots

Although not strictly related to the skin, red light therapy is also used to stimulate hair growth on the head or face in people with areas of low hair density.

What is red light therapy?

Red light therapy is an innovative form of light therapy that has only recently gained mainstream acceptance. This form of therapy uses specific wavelengths of light in the red and infrared spectrum to stimulate biological changes in the body. These changes are believed to cause the skin improvements that people experience when using red light therapy.

Light therapy

Some scientifically minded people who are unfamiliar with light therapy may initially be skeptical about the concept of light therapies in general. The idea that simply shining a light on an area of ​​the body can cause a biological effect may initially sound absurd; however, there are many good examples of light causing biological changes.

The most striking example of how light creates a biological effect is the process of photosynthesis, in which plant cells absorb light and capture its energy, combining carbon dioxide and water to produce oxygen and sugar.

Although humans do not use photosynthesis, there are many biological processes where it is well known and accepted that light influences the body. These include:

• Vitamin D Production - Exposure to specific wavelengths of ultraviolet light stimulates the production of vitamin D in skin cells. Vitamin D that is synthesized using stimulation from sunlight or other light sources containing ultraviolet light is considered more effective and efficient than using vitamin D supplements or eating foods rich in vitamin D.
• Melanin production - Exposure to ultraviolet light stimulates the production of melanin, the molecule that gives skin its darker tone. Increased melanin production is what gives you a tan after spending time in the sun.
• Bilirubin conjugation - Bilirubin is a chemical byproduct of the breakdown of blood cells. While in most people, the liver quickly breaks down bilirubin into other chemicals, a process called “conjugation,” very young babies are sometimes unable to conjugate bilirubin, causing it to build up to toxic levels. Ultraviolet light can be used to conjugate bilirubin in these babies [1], preventing toxicity that can lead to brain damage.
• Vision - For most people, it may be easy to take vision for granted; however, the process of vision is a biological effect caused by light. Light-sensitive cells in the eye undergo a chemical change when exposed to light, causing not only the conscious perception of light, but also subconscious processes that regulate the sleep-wake cycle.

The idea that red light therapy creates a biological effect in the body is consistent with centuries of observations about how light has biological effects.

How does red light therapy work?

Red light therapy is thought to work by stimulating the mitochondria in your cells. Mitochondria are tiny organs in each of your cells; these subcellular organs are primarily known for being the component of the cell that produces all of the cell’s energy. However, they also play an important role in reducing inflammation in the cell and regulating how long the cell lives.

Red light therapy actually uses both red, visible, and infrared, invisible wavelengths of light. The specific wavelengths that red light therapy uses are believed to be absorbed by a molecule in the mitochondria called cytochrome C oxidase [2]. This molecule is part of the electron transport chain, a group of molecules that carry out a series of chemical reactions that result in the production of energy in the cell. Stimulating cytochrome C oxidase likely improves energy production in cells and may be the primary cause of the benefits of red light therapy.

The History of Red Light Therapy

Light therapy in general first gained the attention of medical scientists around 1895, when a Danish physician named Niels Ryberg Finsen began using light to treat infections [3]. Finsen went on to receive one of the first Nobel Prizes in Physiology or Medicine in 1903 for his work.

Research into red light therapy, however, began almost a century later when scientists at NASA [4] were conducting research into using red light wavelengths to stimulate plant growth. While the experiment showed improved plant growth, an accidental discovery was that scientists who spent significant amounts of time exposed to red light experienced rapid healing of skin wounds they had sustained.

This discovery led to a separate line of research that resulted in multiple potential benefits being discovered for red light therapy. These potential benefits included not only improved skin health, but also showed improved sleep quality, decreased inflammation, and improved muscle recovery.

Effect of red light therapy on the skin

To fully understand how red light therapy can help improve the quality and health of your skin, it’s essential to first understand the different ways in which this form of therapy is thought to actually affect your skin. By knowing what red light therapy can do to your skin and the biological effect it can have, you can better understand how red light therapy can help you achieve your skin health goals .

Collagen production

Collagen is a molecule that plays an essential role in skin health. Collagen is a connective molecule that helps skin cells adhere to each other and to other tissues, such as fat cells beneath the skin. Collagen not only helps connect cells and tissues, but it also provides elasticity to the skin, allowing it to stretch and prevent damage.

Collagen is produced naturally in the body from nutrients found in the diet. The amount of collagen produced, however, begins to slowly decline for most people when they reach their mid-20s [5]. The decrease in collagen production is quite gradual, decreasing by only about 1% per year. This effect, however, compounds and causes lower amounts of collagen that become more impactful as we age.

When collagen production slows down, it ultimately leads to the skin becoming less elastic and plump. This is the cause of the wrinkles that develop as we age and the “sagging” skin. Low collagen levels also make the skin more fragile as we age, making it more prone to damage whenever injuries occur.

Research shows [6] that red light therapy can stimulate cells called fibroblasts in your skin. These cells are responsible for producing collagen, and using red light therapy can encourage increased collagen production. According to scientists at Harvard Medical School [7], the effect that red light therapy has on fibroblasts and the levels of collagen they produce may help red light therapy improve symptoms of aging.

Circulation

Blood circulation plays an important role in how well wounds and injuries heal. Blood not only brings the oxygen needed for cells to produce the energy needed to proliferate and heal, but it also brings essential nutrients that serve as building blocks for new cells and tissues.

Good circulation also helps fight infection by bringing immune cells to the site of an injury and helping to remove waste and debris. This promotes healing, but it also reduces pain by reducing the amount of inflammation while encouraging healing at the site of the injury.

Red light therapy has been shown to promote the release of a chemical called nitric oxide where it is used. Nitric oxide helps to dilate the arteries where it is present, increasing blood flow to that specific area. The effect that red light therapy has on the release of nitric oxide is believed to be what causes red light therapy to improve circulation [8]. This improved circulation is one of the main benefits that red light therapy can provide, likely playing a major role in many of its effects.

Cell proliferation

Cell proliferation refers to cells reproducing, leading to an increase in cell numbers. Cell proliferation is an important part of new tissue growth and healing. As cells multiply, the body forms new tissues and structures, repairing previously damaged tissue. The rate of cell proliferation is a key part of what influences the rate of healing.

Red light therapy has been shown to promote cell proliferation [9], especially in cells that are under stress. This may lead to an improved rate of tissue healing and cause wounds to repair themselves more quickly. The exact mechanism of cell proliferation caused by red light therapy is not known, but it is likely to be a combination of mitochondrial stimulation and increased circulation.

Reduced inflammation

Inflammation is a normal part of the body's response to injury. Inflammation results in increased blood flow to an area and increased tissue permeability. These effects cause the area to become redder and warmer to the touch as increased blood flow results. Increased tissue permeability allows immune cells and nutrients to better reach the affected area, but it can also lead to some swelling at the site of the injury.

The inflammatory response plays an important role in healing. Improved blood flow and increased access of immune cells to the site help the area heal in the short term. A byproduct of inflammation is pain, which signals to your consciousness that there is a problem that needs to be addressed.

While inflammation is essential in the short term, it can be very negative if it becomes chronic. People with chronic inflammatory diseases, such as rheumatoid arthritis, will have constant inflammation that causes discomfort and pain, but does not actually result in the body repairing itself.

While inflammation can be caused by disease, it can also be caused by chronic injuries or injuries that take time to heal. Muscle injuries, wounds that become infected, or torn ligaments or tendons can all cause increased inflammation. This can actually make it harder to heal completely, as inflammation is a stage of healing that needs to stop before other stages can occur.

While chronic inflammation can inhibit healing, one of the most aggravating things it causes is pain. The swelling that inflammation causes can cause pain to develop and persist as long as the swelling and inflammation remain. Chronic inflammation often causes chronic pain that is very difficult to treat or control.

The effect that red light therapy has on mitochondria has been shown in research to suppress inflammation [10]. This may promote improved healing, allowing the body to progress beyond the early stages of inflammation and into more advanced healing. Suppressing inflammation also reduces pain, a benefit that many people use red light therapy to achieve.

What skin conditions is red light therapy used to treat?

Red light therapy is a great option for many different types of skin problems, but it should not be used for all types of skin problems. There are several skin conditions, however, that people find red light therapy helpful in treating. Red light therapy should not be used as an alternative to medical care that your doctor prescribes, but rather as a complementary therapy. You should always seek and follow your doctor's advice when treating skin conditions.

It is also important to seek medical advice when diagnosing a skin condition. There are many potential causes of skin problems, and only a qualified doctor can diagnose a skin condition or disease. It is important to never attempt to diagnose a skin condition yourself.

If you have a skin condition that red light therapy can likely help or for which red light therapy seems to make sense, you don’t need a prescription to start therapy. However, it’s a good idea to make sure your doctor knows you’re using red light therapy.

Injuries

The initial discovery that red light therapy could have positive medical effects was in wounds. Using red light therapy to treat wounds is one of the oldest uses of this therapy and has been shown to improve the speed of wound healing [11]. Wounds usually heal on their own without any treatment unless they are severe or infected, but they can heal more quickly when effective treatments are provided.

Red light therapy is used to improve wound healing time, whether it’s an external wound that breaks your skin or an internal wound that affects muscles or other tissues. Open wounds, however, are important to heal as quickly as possible, as healing prevents infections and other complications from having time to develop. This not only ensures that healing occurs, but it also helps reduce the risk of scarring, re-injury, or other complications.

Psoriasis

Psoriasis is a skin condition in which the immune system is believed to trigger excessive proliferation of skin cells. Psoriasis causes scaly, itchy patches of skin. This can lead to discomfort and skin irritation that is difficult to get rid of. One concern that many people with psoriasis have is its cosmetic effect, as it can cause visible and unsightly rashes. The ability to hide these rashes depends largely on the areas that psoriasis affects.

There are several potential treatments for psoriasis, although none of them are a complete cure for the disease. One of the most commonly used treatments that has been shown to help people with psoriasis is light therapy using ultraviolet light. The wavelengths of this form of high-energy light therapy reduce the overgrowth of skin cells and improve psoriasis symptoms in the treated areas.

Red light therapy can be used by people with psoriasis, but it is more likely to improve the symptoms of pain and skin irritation than to actually improve the skin lesions themselves. The inflammation and irritation they cause, however, can be reduced using red light therapy.

One potential benefit of using red light therapy for psoriasis may be that red light therapy helps protect the skin from damage from UV light [12]. UV light used to treat psoriasis may increase the risk of skin cancer eventually developing, and red light therapy may provide a protective effect. The degree to which red light therapy actually provides protection, however, is still the subject of ongoing research.

Melasma

Melasma, also called chloasma or the “mask of pregnancy,” is a common skin condition that causes dark patches to develop on the skin. While pregnancy can increase the risk of developing melasma, it can also develop in non-pregnant women or men.

Melasma usually occurs on the face and is more common in women or people with darker skin. Hormones, sun exposure, stress, and thyroid disease are all considered risk factors for developing melasma. While melasma can go away on its own, especially if it is related to pregnancy or hormone medications, it can also be permanent and often returns if it goes away on its own.

People with melasma often use red light therapy as a means of improving skin quality and reducing the hyperpigmentation that melasma causes. Studies suggest that red light therapy inhibits an enzyme called tyrosinase [13] that produces melanin, the pigment that causes melasma patches to develop. Using red light therapy helps to even out skin tones and may provide cosmetic improvements for those who have melasma.

Post-Inflammatory Hyperpigmentation

Post-inflammatory hyperpigmentation, also called hypermelanosis, occurs when the body produces excess melanin in the skin after inflammation has occurred. In this condition, inflammation causes skin cells to increase melanin production, leading to darker skin in the areas that were inflamed.

Although post-inflammatory hyperpigmentation will fade on its own, this process can take a few years or longer. Because post-inflammatory hyperpigmentation leads to discoloration that can be cosmetically undesirable, many people who develop this condition prefer to try methods like red light therapy to speed up the process.

As with people with melasma, red light therapy is used by those with post-inflammatory hyperpigmentation for its effect on evening out skin tone and reducing dark spots caused by excess melanin production. By suppressing melanin production, red light therapy can improve discoloration caused by post-inflammatory hyperpigmentation.

Acne

Acne is a skin condition that causes hair follicles to become clogged, leading to blocked pores. This leads to the development of blackheads and whiteheads that can become infected or cause scarring. Acne commonly affects the face, creating an obvious cosmetic defect that can be very undesirable.

Bacterial infections can cause acne; however, the blackheads and whiteheads associated with acne can also be linked to many other causes. Light therapy has been studied to treat acne, with both ultraviolet light therapy and red light therapy being helpful [14]. Ultraviolet light is thought to provide its benefit by helping to destroy bacteria that may be clogging the pore, while red light therapy improves healing and reduces the risk of developing long-term scars.

Scars

Scars develop when an injury does not heal in a way that returns the skin or affected area to its original appearance. Scars can develop after injuries, but they can also be a concern after surgery or when stretch marks develop. Scars are usually a long-term problem that can be permanent if left untreated.

Red light therapy may help reduce the likelihood of scars [15] developing after an injury or may reduce the severity of existing scars. Decreasing inflammation and improving circulation, two effects commonly associated with red light therapy, will help injuries heal properly. This reduces the likelihood of scar tissue developing due to impaired healing and increases the chances that full and complete healing will occur.

Several effects associated with red light therapy also help existing scars heal partially or completely. Increased collagen production can help damaged skin tissue regain its elasticity. This can be especially helpful for stretch-related scars, such as stretch marks after pregnancy. Increased circulation and even skin tone can help scarred areas heal better, making the skin more even and helping it look more consistent with its pre-injury appearance.

Age-related changes

As we age, our skin goes through a number of changes. Some of these changes are cosmetic, primarily changing the appearance of your skin. Others are more structural, affecting how your skin functions. Often, structural changes will lead to cosmetic changes, as they affect the normal function of the skin and increase the risk of damage.

Age-related skin changes have two main causes. First, there are normal changes that occur with aging. With skin, decreased collagen production is the main cause of these changes, but circulation and hormonal changes can also play a role. Second, damage accumulates over time. Whether it’s sun exposure, tobacco use, or even injury, the more time your skin has to accumulate damage, the more changes it will experience.

In addition to age-related changes, as we get older, we tend to take more and more medications. Many medications can affect the quality of our skin and cause skin damage. While not specifically age-related, the likelihood of this occurring increases as we get older.

There are three main age-related changes that many people commonly experience as they get older. They include:

• Age spots - Also called liver spots, age spots are increasingly common with age. These spots are also more common in people with greater amounts of sun exposure throughout their lives. Age spots appear as flat brown, black, or tan patches on the skin.
• Wrinkles - Because collagen is less abundant, the skin has less elasticity. This makes the skin less able to hold its shape and causes wrinkles to appear. Wrinkles begin to develop in areas of the skin that are commonly wrinkled, but eventually spread out.
• Fragility - As skin loses its elasticity and ability to hold its shape, it becomes more fragile. Decreased connectivity between skin cells and other cells makes it easier for the skin to tear or separate from other layers of tissue.

Red light therapy is used to reduce age-related changes in the skin by stimulating collagen production and evening out skin tone. Helping skin tone become more even by inhibiting excess melanin production will help age spots fade. Increased collagen production helps skin look firmer and wrinkle less.

More research on red light therapy for skin health

In addition to the research we’ve already discussed specific to different skin conditions, there is a much larger body of research supporting the benefits of using red light therapy to promote skin health and well-being.

Studies on red light therapy for skin

Skin-related studies exploring red light therapy can be in vivo, performed on humans, but are also often in vitro , performed in a laboratory setting on cells taken from humans or animals. Skin cells are particularly well-suited to in vitro studies, providing greater insights into what biological effects are actually occurring.

In vitro studies

In 2015, researchers conducted an in vitro study [16] exposing cultured human cells to red LED lights. The results were published in the International Journal of Photoenergy and showed that exposure to 660 nm red light increased the rate at which skin cells multiplied and helped improve their migration.

An article from the Journal of Wound Management and Research [17] published in 2018 also tested the effects of light on cultured skin cells. The researchers found that red light or red light combined with infrared light “could modulate fibroblast proliferation and collagen synthesis.” They also determined that the combination of red light and infrared light produced better results than red light alone.

In 2019, the Journal of the American Academy of Dermatology published research [18] that found that treating skin cells with low-level red and infrared LED lights “significantly increases the gene expression of hyaluronic acid synthase (HAS2) and elastin (ELN).” These genes are related to the production of hyaluronic acid and elastin, two molecules that play an important role in keeping your skin hydrated, supple, and elastic and that decline as we age. The researchers found that these effects occurred in just three days. The researchers noted, “Because low-level red and infrared light stimulated the production of several biomarkers associated with anti-aging skin benefits, these findings suggest that low-level red and infrared light treatments present opportunities for daily at-home treatments for patients with photoaging and photodamaged skin.”

Another study [19] was also published in 2019, examining the effects of red light therapy on skin healing. Published in PLOS One , this study used in vitro porcine (pig) skin that researchers were able to damage and then examine its recovery when exposed to light. The researchers found that using red light for at least 10 minutes sped up the recovery of the samples, while blue and purple light did not.

In 2021, a study [20] published in the International Journal of Cosmetic Science found that using red light or infrared light to treat cultured human skin cells increased the expression of four different genes associated with skin health, increased collagen production, increased elastin production, and improved protein connectivity in the skin. The study also found increased production of ATP, the molecule used by cells for energy, when red light and infrared light were combined.

A very interesting study [21] published in Frontiers in Oncology in 2022 showed that red light used on melanoma cells, cells from a certain type of skin cancer, “prevented tumor growth and increased the expression of immune markers.” These results are very early and do not mean that red light therapy should be used to treat skin cancer; however, they do indicate that future research into this possibility is needed.

A 2023 study [22] published in Lasers in Medical Science studied human skin cell cultures exposed to 661 nm (red) light. The study showed that the skin cell cultures not only healed more quickly when exposed to this light, but that the healing was in part due to an effect that resulted in the cells orienting themselves more effectively and moving to the areas where they were needed.

In vivo studies

A 2014 study [23] published in the Journal of Clinical and Experimental Dermatology Research followed 29 patients who underwent broadband infrared therapy once a month for five months. After these treatments, 76% of the test subjects reported that they were satisfied to very satisfied with the treatments. The results measured included degrees of wrinkles in the tested area, wrinkles at the corners of the eyes, and sagging cheek skin, with more than three-quarters of the test subjects noticing changes in each of these measures.

A very important study [24] was published in 2020 in the Journal of Biophotonics . This study examined the safety profiles of red light therapy by testing the effects of red light therapy on a diverse group of 155 people. The study looked at specific differences in how safe red light therapy was in people with differences in skin pigmentation. Specifically, they found that red light therapy was “safe up to 320 J/cm2 for skin of color and 480 J/cm2 for non-Hispanic Caucasian individuals.” This finding indicates that those with darker skin pigmentation may absorb more red light and be more susceptible to dose-related complications from red light therapy.

A 2020 controlled study [25] published in BMJ Open examined the effects of using high-intensity red light to treat chronic wounds. The study included 60 people and found that the therapeutic effects of using the treatment on chronic wounds that healed poorly “are significant and far superior to those of conventional dressings.”

Red Light Therapy for Skin Reviews

In addition to the many independent studies demonstrating the benefits of red light therapy for skin health, there are several important reviews. These reviews bring together data from many studies, helping to better contextualize the research that has been conducted and its implications. Reviews also play an important role in suggesting potential new research avenues, protocols, and ways to strengthen existing research.

Some recent important reviews on the state of red light therapy research as it relates specifically to skin health include:

• A 2013 review [26] published in Seminars in Cutaneous Medicine and Surgery . The review found that red light therapy “appears to have a wide range of applications in dermatology, especially in indications where stimulation of healing, reduction of inflammation, reduction of cell death, and skin rejuvenation are required.” The review also noted that it could reduce the damage caused by ultraviolet light, both by preventing it and by treating it afterward. This review occurred before the widespread use of red light therapy in dermatology and likely played a role in its widespread adoption.
• A 2015 review [27] published in the Biomedical and Pharmacology Journal . This review looked at the different methods of delivering red light therapy, as well as different potential explanations for how red light therapy actually works. The study helped shed light on how red light therapy impacted healing and noted that more research was needed to determine the parameters that should be used to administer red light therapy.
• A 2016 review [28] published in Wound Healing . This study reviewed red light therapy protocols and noted an increase in the clinical use of red light therapy to treat wounds and ulcers. The study also reviewed how experiments have confirmed the potential beneficial effects of red light therapy for wound healing.
• A 2018 review [29] published in Lasers in Medical Science . The review noted that red light therapy “represents the emerging and safest tool for the treatment of many conditions, such as inflammatory skin conditions, aging, and hair growth-related disorders.” The review also noted that red light therapy “has now entered common practice among dermatologists,” but recommended that more controlled studies be conducted to better establish its efficacy.
• Another 2018 review [30] was published in Medical Research Archives . This review found that the volume of research on red light therapy for skin care had doubled in the previous eight years. The review explored several benefits of red light therapy that had been studied, including its use to treat skin wounds, erosive mucositis in oncology, leg ulcers, burns, radiodermatitis, acne, and hypertrophic scars. It also noted that red light therapy reduces inflammation after other skin treatments that can cause inflammation. The review also identified several new potential applications in which red light therapy was showing promise. These areas included alopecia, cellulite, and other skin conditions.
• A 2021 review [31] published in the Aesthetic Surgery Journal . This review concluded that “there is a reasonable body of evidence from clinical trials to support the role of low-energy red/near-infrared light as a safe and effective method of skin rejuvenation, treatment of acne vulgaris and alopecia, and especially body contouring.” The review also suggested potential methods to improve future studies, such as improving methodologies and the number of patients included in each study.

How is red light therapy used?

Using red light therapy to improve your skin health is relatively simple. Before you get started, however, there are a few steps you should take:

1. Make sure you don't have any contraindications . Not everyone should use red light therapy, and you should make sure there are no reasons why you shouldn't use it. If you're unsure, you should consult your doctor before using it.
2. Learn about red light therapy. There can be big differences in the quality of different red light sources, and there’s more to it than just having a red light source. Make sure you understand the quality of the products you’ll be using.
3. Make sure you have access to red light therapy . The changes that red light therapy provides are worthwhile, but they tend to be more gradual. To use red light therapy correctly, you will need to have regular access to a red light therapy panel or device.

When you are ready to start using red light therapy, performing the treatment is quite easy.

1. Turn on the red light source.
2. Be sure to wear protective eyewear.
3. Make sure the area to be treated is uncovered.
4. Position yourself about 30 to 40 centimeters from the source.
5. Allow the light source to irradiate the area to be treated for 10 to 20 minutes.
6. Repeat regularly, three to seven times a week.

If the manufacturers of the red light panel or your doctor give different instructions about the length of time, distance, frequency, or other factors, you should follow their advice.

TheraFactor Red Light

As TheraFactor, we provide a wide variety of red light therapy products that are designed to deliver specific wavelengths of light that are thought to help improve the cellular function of skin cells and thus improve overall skin health. Our panels are designed to deliver the maximum amount of the right light to the largest area possible.

Customer feedback on skincare has been excellent. Check out some before and after photos of red light therapy and our growing repository of glowing reviews .

DISCLAIMER : TheraFactor devices are not clinically proven to diagnose, treat, cure or prevent any medical conditions. TheraFactor devices are Class II general wellness devices intended to affect the body through topical heating and support of cellular function. The scientific studies referenced in this article are for informational purposes only.

References:

1. Woodgate, P., & Jardine, L. A. (2015). Neonatal jaundice: phototherapy. BMJ Clinical Evidence , 2015, 0319. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4440981/

2. Tafur, J., & Mills, P. J. (2008). Low-intensity light therapy: exploring the role of redox mechanisms. Photomedicine and Laser Surgery, 26(4), 323–328. https://doi.org/10.1089/pho.2007.2184

3. Nobel Prize Outreach AB. (2023). The Nobel Prize in Physiology or Medicine 1903. https://www.nobelprize.org/prizes/medicine/1903/summary/

4. Cotler, H. B. (2015). A NASA discovery has current applications in orthopedics. Current Orthopaedic Practice, 26 (1), 72–74. https://doi.org/10.1097/BCO.00000000000000196

5. Obagi, S. (2005, September 26). Why does skin wrinkle with age? What is the best way to slow or prevent this process? Scientific American. https://www.scientificamerican.com/article/why-does-skin-wrinkle-wit/

6. Wunsch, A., & Matuschka, K. (2014). A controlled trial to determine the efficacy of red and near-infrared light treatment on patient satisfaction, reduction of fine lines, wrinkles, skin roughness, and increased intradermal collagen density. Photomedicine and Laser Surgery, 32 (2), 93–100. https://doi.org/10.1089/pho.2013.3616

7. Harvard Health Publishing. (2019, October 1). LED Lights: Are They a Cure for Your Skin Woes? https://www.health.harvard.edu/diseases-and-conditions/led-lights-are-they-a-cure-for-your-skin-woes

8. Keszler, A., Lindemer, B., Weihrauch, D., Jones, D., Hogg, N., & Lohr, N. L. (2017). Red/near-infrared light stimulates the release of an endothelium-dependent vasodilator and rescues vascular dysfunction in a model of diabetes. Free Radical Biology and Medicine , 113, 157–164. https://doi.org/10.1016/j.freeradbiomed.2017.09.012

9. Ayuk, S. M., Houreld, N. N., & Abrahamse, H. (2018). Effect of 660 nm visible red light on cell proliferation and viability in in vitro diabetic models under stress conditions. Lasers in Medical Science, 33 (5), 1085–1093. https://doi.org/10.1007/s10103-017-2432-2

10. Hamblin, M. R. (2017). Mechanisms and applications of the anti-inflammatory effects of photobiomodulation. AIMS Biophysics, 4 (3), 337–361. https://doi.org/10.3934/biophy.2017.3.337

11. Chaves, MEA, Araújo, AR, Piancastelli, ACC, & Pinotti, M. (2014). Effects of low-level phototherapy on wound healing: LASER x LED. Brazilian Annals of Dermatology, 89 (4), 616–623. https://doi.org/10.1590/abd1806-4841.20142519

12. Barolet, D., Christiaens, F., & Hamblin, M. R. (2016). Infrared and skin: friend or foe. Journal of Photochemistry and Photobiology B: Biology , 155, 78–85. https://doi.org/10.1016/j.jphotobiol.2015.12.014

13. Kim, J. M., Kim, NH., Tian, ​​Y. S., & Lee, A. Y. (2012). Light-emitting diodes at 830 and 850 nm inhibit melanin synthesis in vitro. Acta Dermato-Venereologica , 92, 675–680. https://doi.org/10.2340/00015555-1319

14. Pei, S., Inamadar, A.C., Adya, K.A., & Tsoukas, M.M. (2015). Light-based therapies in the treatment of acne. Indian Dermatology Online Journal, 6 (3), 145–157. https://doi.org/10.4103/2229-5178.156379

15. Kurtti, A., Nguyen, J. K., Weedon, J., Mamalis, A., Lai, Y., Masub, N., Geisler, A., Siegel, D. M., & Jagdeo, J. R. (2021). Light-emitting diode-red light for post-surgical scar reduction: Results of a randomized, split-face, dose-ranging clinical trial. Journal of Biophotonics, 14 (7), e202100073. https://doi.org/10.1002/jbio.202100073

16. Kim, MS., Cho, YI., Kook, MS., Jung, SC., Hwang, YH., & Kim, BH. (2015). Effect of 660 nm light-emitting diode on wound healing in fibroblast-like cell lines. International Journal of Photoenergy , 2015, Article ID 916838. https://doi.org/10.1155/2015/916838

17. Ma, H., Yang, J.P., Tan, R.K., Lee, H.W., & Han, SK. (2018). Effect of low-level laser therapy on proliferation and collagen synthesis of human fibroblasts in vitro. Journal of Wound Management and Research, 14 (1), 1-6. https://doi.org/10.22467/jwmr.2018.00283

18. Kim, B., Mukherjee, A., Seo, I., Fassih, A., Southall, M., & Parsa, R. (2019). Low-level red and infrared light increase the expression of collagen, elastin, and hyaluronic acid in the skin. Journal of the American Academy of Dermatology, 81 (4), AB434. https://doi.org/10.1016/j.jaad.2019.10.089

19. Abe, Y., Konno, H., Yoshida, S., Yamauchi, T., Yamasaki, K., Denda, M., & Nishizawa, M. (2019). Skin barrier recovery promoted by red light: spatiotemporal evaluation by transepidermal potential. PLOS ONE, 14 (7), e0219198. https://doi.org/10.1371/journal.pone.0219198

20. 11. Li, W.-H., Seo, I., Kim, B., Fassih, A., Southall, M.D., & Parsa, R. (2021). Combination of low-level red plus near-infrared lights induces collagen and elastin expressions in human skin in vitro. International Journal of Cosmetic Science, 43 (3), 311-320. https://doi.org/10.1111/ics.12698

21. Austin, E., Huang, A., Wang, J. Y., Cohen, M., Heilman, E., Maverakis, E., Michl, J., & Jagdeo, J. (2022). Red light phototherapy using light-emitting diodes inhibits melanoma proliferation and alters tumor microenvironments. Frontiers in Oncology , 12. https://doi.org/10.3389/fonc.2022.928484

22. Giannakopoulos, E., Katopodi, A., Rallis, M., Politopoulos, K., & Alexandratou, E. (2023). The effects of low-power laser light at 661 nm on wound healing in a scratch assay fibroblast model. Lasers in Medical Science, 38 (1), 27. https://doi.org/10.1007/s10103-022-03670-5

23. Hirao, A., Morita, R., & Kawada, A. (2014). Clinical efficacy of broadband infrared light therapy for wrinkles and facial skin laxity. Journal of Clinical and Experimental Dermatological Research, 5 (5). https://doi.org/10.4172/2155-9554.1000233

24. Jagdeo, J., Nguyen, J. K., Ho, D., Wang, E. B., Austin, E., Mamalis, A., Kaur, R., Kraeva, E., Schulman, J. M., Li, C.-S., Hwang, S. T., Wun, T., Maverakis, E., & Isseroff, R. R. (2020). Safety of red light from light-emitting diode on human skin: two randomized controlled trials. Journal of Biophotonics, 13 (3), e201960014. https://doi.org/10.1002/jbio.201960014

25. Lu, Q., Yin, Z., Shen, X., Li, J., Su, P., Feng, M., Xu, X., Li, W., He, C., & Shen, Y. (2021). Clinical effects of high-intensity laser therapy in patients with chronic refractory wounds: a randomized controlled trial. BMJ Open , 11, e045866. https://doi.org/10.1136/bmjopen-2020-045866

26. Avci, P., Gupta, A., Sadasivam, M., Vecchio, D., Pam, Z., Pam, N., & Hamblin, M. R. (2013). Low-level laser (light) therapy (LLLT) in skin: Stimulation, healing, restoration. Seminars in Cutaneous Medicine and Surgery , 32, 41-52. https://scmsjournal.com/articles/view_pdf/low-level-laser-light-therapy-lllt-in-skin-stimulating-healing-restoring

27. Rashidi, S., Yadollahpour, A., & Mirzaiyan, M. (2015). Low-level laser therapy for the treatment of chronic wounds: clinical considerations. Biomedical and Pharmacology Journal, 8 (2). https://dx.doi.org/10.13005/bpj/866

28. Bayat, M. (2016). The need for increased attention to low-level laser therapy as a treatment for wounds and ulcers. In Wound healing - New insights into old challenges . https://doi.org/10.5772/64339

29. Sorbellini, E., Rucco, M., & Rinaldi, F. (2018). Photodynamic and photobiological effects of light-emitting diode (LED) therapy in dermatological diseases: an update. Lasers in Medical Science , 33, 1431–1439. https://doi.org/10.1007/s10103-018-2584-8

30. Barolet, D. (2018). Photobiomodulation in Dermatology: Harnessing Light from the Visible to Near-Infrared for Medical and Aesthetic Purposes. Archives of Medical Research, 6 (1). https://esmed.org/MRA/mra/article/view/1610/1689
31. Glass, GE (2021). Photobiomodulation: The clinical applications of low-level light therapy. Aesthetic Surgery Journal, 41 (6), 723–738. https://doi.org/10.1093/asj/sjab025