Sunburn is skin damage caused by overexposure to ultraviolet (UV) radiation, triggering an inflammatory response that results in redness, pain, and heat. Red Light Therapy (RLT), also known as photobiomodulation, is a non-invasive treatment that uses specific wavelengths of light (red and near-infrared) to promote cellular repair. This therapy is being explored to support the body’s natural healing process after acute sun damage. The light delivered during RLT does not contain the damaging UV rays responsible for the burn. Understanding RLT’s cellular interaction and application protocols is necessary to determine its effectiveness for managing sunburn discomfort and accelerating recovery.
How Red Light Interacts with Sunburned Skin
Sunburn causes widespread cellular stress and inflammation in the skin. Red and near-infrared light penetrate the skin to interact directly with the cells’ mitochondria. The primary photoacceptor is cytochrome c oxidase, an enzyme located within the mitochondrial respiratory chain. When light is absorbed, it displaces inhibitory nitric oxide, allowing mitochondria to function more efficiently. This process increases the production of adenosine triphosphate (ATP), providing damaged skin cells with the energy needed for accelerated repair and regeneration.
RLT helps modulate the inflammatory response triggered by UV exposure. It reduces inflammatory signals, which helps lessen the characteristic redness, heat, and swelling associated with sunburn. By mitigating oxidative stress present in burned tissue, RLT supports faster healing and may reduce the risk of peeling or long-term damage.
Practical Guidelines for Red Light Application
The effectiveness of RLT depends significantly on using the correct light wavelengths. For surface-level damage like sunburn, red light in the 660 nanometer (nm) range is preferred because it targets the superficial layers where UV damage is concentrated. While near-infrared light (around 850 nm) penetrates deeper, 660 nm red light is most effective for stimulating healing activity in the dermis.
Treatment Timing and Duration
Starting treatment as soon as possible after the burn occurs is recommended to maximize anti-inflammatory benefits. The recommended duration per affected area is short, generally ranging from 5 to 15 minutes, depending on the device’s intensity. Users should aim for one or two sessions daily, allowing a few hours between treatments for the skin to respond. Consistency over the first few days post-sunburn can significantly accelerate recovery for mild to moderate burns.
Important Safety Precautions
RLT should not be used on severe sunburns involving blistering, peeling, or signs of secondary infection; these conditions require professional medical attention. While RLT devices do not emit UV light, users must protect their eyes from the intense visible and invisible light, especially near-infrared wavelengths, by wearing the provided protective eyewear.
People taking photosensitizing medications (such as certain antibiotics, anti-inflammatory drugs, and retinoids) should use RLT with caution or avoid it after consulting a healthcare provider. These medications can increase the skin’s sensitivity to light, potentially causing an adverse reaction. The device should not generate excessive heat, as adding thermal energy to burned skin will worsen discomfort. If the skin feels uncomfortably warm, stop the treatment immediately or increase the device distance, adhering strictly to the manufacturer’s instructions.