More often than not, a device’s performance success is equated to power, so it can be easy to assume that the most intense red light therapy device must deliver the best results. But when it comes to photobiomodulation (PBM), this mindset can be misleading and counterproductive.
Rather than amplifying outcomes, excessive light intensity can reduce therapeutic efficacy or even halt it altogether. Delve into how red and infrared light therapy dosing works and why maximising their benefits is more dependent on the right dose rather than more power with our team at Rojo Light Therapy EU.
Ever since research into red and infrared light therapy began in the 1960s, most research and application of the treatment were done with lasers. Only in the 1990s did scientists begin studying light-emitting diodes (LEDs).
Given this, many early companies in the field created higher-powered red and infrared light therapy devices, often trying to get close to the power of lasers and citing laser research to showcase benefits.
However, with more studies emerging on LED light therapy and devices, it’s becoming clearer that not all PBM treatments require high intensities to be effective.
In photobiomodulation, irradiance or the power delivered per square centimetre (mW/cm²) is one of the most critical factors in determining how effectively the body absorbs and uses light energy. But contrary to what many believe, higher power does not necessarily mean better outcomes.Â
The key lies in matching the radiance level to the therapeutic goal.
This range typically lies within 5 to 20 mW/cm² and is most often used for surface-level treatments. Studies have found that by increasing collagen and elastin production, which are essential proteins in skin rejuvenation, the treatment can decrease fine lines, and heal minor wounds.
Red and infrared light also helps prevent inflammation, which can exacerbate many skin problems.
Low radiance also allows for longer session durations without risking overstimulation, making it ideal for regular cosmetic use or sensitive skin.
This range is around 20 to 60 mW/cm², and penetrates deeper into the tissue while still maintaining a balance between intensity and safety. This level is often used for muscle recovery, joint discomfort, and circulatory stimulation.
Anything from 60 up to 100 mW/cm² or more, is designed for targeted applications requiring deep penetration such as managing chronic pain, addressing deeper muscular or nerve-related issues, or performing transcranial photobiomodulation.
While this range can be highly effective, it also requires more precise application. The therapeutic window is narrow, and going beyond it can lead to overstimulation, tissue fatigue, or a plateau in results.
The misconception that more intensity equals better results is especially common among newcomers to red light therapy. However, several factors illustrate why a lower, carefully modulated dose often outperforms higher intensities:
The biphasic dose-response curve, often referred to as the Arndt-Schulz curve, states that low levels of light can stimulate tissue repair and growth, whereas higher levels may have inhibitory effects.
In a 2003 study, for instance, researchers observed a biphasic dose response in human fibroblast cells. The cells reached a maximum increase in production after irradiation of light at 628 nm at 0.88 J/cm² and a marked reduction at 9 J/cm².
Higher power settings don’t just risk biological overstimulation. They also increase the risk of thermal buildup. While red and near-infrared light treatments are safe at appropriate doses, too much intensity delivered too quickly can lead to superficial tissue heating without deeper penetration.Â
This is especially concerning in home devices that lack sophisticated pulse modulation or thermal regulation.
The penetration depth of light in biological tissues is primarily influenced by its wavelength. This also determines what issues can the treatment treat more effectively. That’s why it’s more important to consider your treatment wavelength rather than the intensity of the device.
Consistency and cumulative dosing are the keys to successful red and infrared light therapy treatments. It’s generally recommended to start with a few short sessions per week and to gradually increase them as the body adjusts.
The body needs time to integrate and respond to cellular changes. Overloading it can delay the healing process rather than accelerate it.
Understanding that more power isn’t always better removes the pressure to chase the most intense devices and redirects your attention to what truly matters: optimal wavelength, consistent treatment, and proper dosing over time.
Whether you're targeting inflammation, chronic pain, skin conditions, or cognitive support, the best results come from well-engineered photobiomodulation for your needs.
That’s why Rojo Light Therapy crafts red light devices grounded in the latest technology, using precision-calibrated wavelengths and user-friendly designs that make consistent, effective therapy easy to achieve at home.
Explore our range today or contact us for more inquiries.
