Red light therapy, also known as low-level light/laser therapy (LLLT), is a treatment that uses red light from a panel of LEDs or lasers to treat the skin, with the supposed benefits of stimulating collagen production and reducing signs of aging. Because red light therapy is applied directly to the skin to have an effect, many with skin concerns are wondering if they need to wear sunscreen to protect their skin while getting the treatment.
In this article, we will explain the science behind how red light therapy works and whether you need to use sunscreen to protect your sensitive skin.
What is red light therapy?
Red light therapy (RLT) is a type of phototherapy that uses specific wavelengths of light in the red and near-infrared spectrum. It was first discovered in the 1960s by a scientist in Hungary who found that his low-powered laser accelerated wound healing and hair regrowth in laboratory rats.
Medical research has reported that red light therapy may have some benefits in the reduction of inflammation, wound healing, and tissue regeneration. Other potential red light therapy applications include pain relief in arthritis patients and the treatment of skin issues, such as acne and psoriasis.
Online, RLT is widely promoted as a cosmetic skin treatment, and many companies sell a range of red-light therapy devices online, such as masks and helmets lined with LEDs or low-power lasers aimed at improving skin complexion, reducing wrinkles, and reversing or slowing the signs of skin aging.
How does red light therapy treatment work?
The exact mechanism of how RLT works isn’t fully understood. It’s thought that it works on a cellular level, when the wavelengths of light are absorbed by the cells in our skin and tissues, boosting their metabolism and ability to heal, repair, and recover.
Inside every cell in our body, there are small structures called mitochondria, responsible for producing the energy they need to function. It is theorized that the lightwaves are absorbed by an enzyme called Cytochrome C Oxidase (CCO), which kicks off a chain reaction that increases mitochondrial function.
Scientists also hypothesize that it stops the nitric oxide from binding to CCO, which is believed to slow down the energy production in mitochondria. By removing the nitric oxide, it's thought that the mitochondria continue producing energy, therefore supplying cells for function.
Since RLT was discovered, there have been a number of studies that have found potential benefits of red light therapy. These include benefits such as improving hair growth in people assigned male at birth (AMAB) with male pattern hair loss and potentially reducing some side effects of treatment in cancer patients.
Do you need sunscreen for red light therapy?
The light used in red light therapy treatment is on one side of the light spectrum, and the damaging ultraviolet light such as UVA and UVB is on the other end of the spectrum from red and near-infrared. This means they have completely different wavelengths and different effects on the skin.
Because sunscreen is formulated to block UV rays and RLT does not involve UV, there’s no clear basis to use sunscreen for RLT.
While sunscreen isn't specifically designed to block red light, some sunscreens contain ingredients like titanium dioxide and zinc oxide that might affect it. These ingredients absorb UV radiation, but research suggests that higher light wavelengths, like the ones used in red light therapy, may be reflected or scattered from the skin, stopping it from having a full effect.
UV light vs. red light
UV rays from the sun damage the DNA in our skin cells, leading to sunburn, premature signs of aging, and some forms of skin cancer. When our skin is exposed to UV from the sun, our skin responds by stimulating the production of melanin, which gives it a darker pigment, known as tanning. This is actually our skin trying to protect us against UV damage.
Over time, this can develop into age spots and blemishes. UV rays also break down the collagen and elastin, leading to wrinkles and sagging skin. Repeated sun exposure also increases the risk of cancers, such as melanoma, making it vital to block UV rays from our skin with sunscreen. Skin cancer is the most common cancer in the United States, and UV radiation is one of the leading risk factors for cancer.
Because red and near-infrared frequencies do not contain UV light, they are believed to be safe for the skin when used as directed and are not associated with the harmful effects of UV rays.
However, if you are in the sun, you should always use appropriate, regular sun protection on sun-exposed areas.
To better understand how to protect your skin, read our comparison of sunblock vs. sunscreen and learn how to choose the best sunscreen for your face.
How does red light therapy affect the skin?
RLT offers promising benefits for skin health and rejuvenation. This non-invasive treatment is gaining popularity for its potential to improve various skin concerns without the need for invasive procedures.
It is thought that RLT works by stimulating cells involved in skin and tissue regeneration. These include fibroblasts, which stimulate collagen production and healing; keratinocytes, which form the outer layer of the skin and play a crucial role in its barrier function; and immune cells like mast cells, neutrophils, and macrophages, which are vital for dermal defense and repair mechanisms. These wavelengths of light may enhance the function and activity of these cells, leading to improved health and appearance.
For more information on how to effectively use red light therapy at home, check out our guide on red light therapy masks.
How to prepare your skin for a red light therapy session
There’s no official guidance on how to prepare your skin for red light therapy session. Some individuals choose to continue their regular skincare routine beforehand, but most clinics advise people to cleanse beforehand to remove sunscreen, makeup, or any skincare products that might block the red light and reduce the amount of light reaching the skin. Moreover, there are few studies exploring whether skincare ingredients can interact with red light therapy and cause adverse effects.
The skin may be sensitive after a red light therapy session, and your dermatologist may advise you to avoid sun exposure for 48 hours after certain types of phototherapy.
While RLT does not involve harmful UV light, it is crucial to consult with a healthcare provider before starting any new treatment to ensure it is suitable for your skin type. Personalized advice from a professional can help you maximize the benefits and avoid potential risks before adding RLT to your regular skincare routine. The use of sunscreen with RLT is generally not necessary since the therapy does not include UV light, which is the primary concern for sun protection.
If you have any questions about RLT, leave them in the comments section below. Engaging with our community will help us provide insights and support on your skincare journey.
FAQ
Does sunscreen block red light therapy?
Sunscreen is designed to block UV light, not red light. However, some ingredients like titanium dioxide and zinc oxide might reflect or scatter red light, potentially reducing the amount of light that reaches your skin during RLT.
Should red light therapy be done on bare skin?
Yes, for best results, red light therapy should be performed on clean, bare skin to ensure the light penetrates effectively without any barriers like sunscreen or makeup. For specific advice regarding your skin type and concerns regarding RLT, consult with your dermatologist.
Should you wear lotion when doing red light therapy?
It's generally recommended to avoid lotions before red light therapy. Clean, bare skin allows the light to penetrate more effectively, potentially enhancing the benefits.
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Red light therapy (RLT) is believed to enhance skin health by stimulating collagen production and tissue regeneration.
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RLT uses non-thermal, red and near-infrared light to potentially improve skin complexion and reduce wrinkles.
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Unlike UV light, RLT is thought to be safe for the skin and does not require sunscreen.
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Some types of sunscreen may block the rays of RLT from reaching your skin by reflecting or scattering red light.
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Cleansing the skin before RLT sessions may enhance treatment results.
13 resources
- BBA Clinical. Shining light on the head: photobiomodulation for brain disorders.
- Springer. A clinical review of phototherapy for psoriasis.
- Cureus. Effect of low-level laser therapy on early wound healing and levels of inflammatory mediators in gingival crevicular fluid following open flap debridement.
- Journal of Lasers in Medical Science. Low-level laser therapy for rheumatoid arthritis: a review of experimental approaches.
- HHS Manuscripts. Low-level laser (light) therapy (LLLT) in skin: stimulating, healing, restoring.
- Journal of Cutaneous and Aesthetic Surgery. Role of low-level light therapy (LLLT) in androgenetic alopecia.
- Photomedicine and Laser Surgery. Photobiomodulation and cancer: what is the truth?
- Photomedicine and Laser Surgery. A controlled trial to determine the efficacy of red and near-infrared light treatment in patient satisfaction, reduction of fine lines, wrinkles, skin roughness, and intradermal collagen density increase.
- Wiley Open Access. The impact of ultraviolet radiation on skin photoaging — review of in vitro studies.
- Journal of Biophotonics. Safety of light emitting diode-red light on human skin: two randomized controlled trials.
- Journal of Clinical and Aesthetic Dermatology. Sunscreening agents.
- Photodermatology, Photoimmunology & Photomedicine. Metal oxide sunscreens protect skin by absorption, not by reflection or scattering.
- American Academy of Dermatology Association. Lasers and lights: how well do they treat acne?
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