Pulsed Infrared Light Therapy: What It Is and Why It Matters
If you have been researching red light therapy, you have likely come across a distinction that does not always get the explanation it deserves: the difference between continuous wave LED and pulsed infrared light therapy.
This is not a minor technical detail. The way light is delivered to your skin fundamentally changes the biological response it produces, and the research behind pulsed delivery is increasingly compelling.
What Is Pulsed Infrared Light Therapy?
Pulsed infrared light therapy is a form of photobiomodulation where the light source is switched on and off at a set frequency rather than shining continuously. This creates a rhythmic pattern of light bursts and rest periods.
Depending on the pulse frequency, this switching may or may not be visible to the naked eye. Low frequencies below 50 Hz produce pulses that can be perceived as a flicker, while higher frequencies above 100 Hz appear as steady light even though the pulses are occurring.
Traditional LED therapy devices deliver what is called continuous wave (CW) light: the LEDs stay on throughout the treatment session. Pulsed light therapy changes this, introducing deliberate off-periods between bursts of light. This seemingly simple modification has significant downstream effects on how cells respond.
The Cellular Case for Pulsing
The reason pulsed infrared light therapy produces different outcomes from continuous wave comes down to how cells handle energy, waste products, and the need for periodic recovery.
During a standard LED session using continuous light, the mitochondria in skin cells produce ATP and generate reactive oxygen species (ROS) as a byproduct. In moderate amounts, ROS serve as signalling molecules that initiate the repair and regeneration cascade photobiomodulation is known for.
However, under prolonged continuous exposure, ROS can accumulate to levels where they become counterproductive. Excess ROS makes the water within the mitochondrial membrane more viscous, slowing ATP synthase activity and reducing cellular energy production. This is what researchers sometimes call moving outside the "Goldilocks zone" of optimal cellular stimulation.
Pulsed light prevents this by giving cells recovery periods. When the light is off, cells consume their ATP reserves and excess ROS dissipate. When the light comes back on, cells can respond afresh. This cyclical stimulation has been shown to produce greater ATP output, more active cell proliferation, and higher collagen synthesis compared to continuous wave at the same wavelength.
A comprehensive review by Hashmi et al. published in Lasers in Surgery and Medicine examined the effect of pulsing in low-level light therapy and found that pulsed treatments consistently showed enhanced effects in promoting cell proliferation and reducing inflammation compared to continuous wave, with increased ATP production and reduced oxidative stress across multiple study designs.
Higher Peak Power Without Higher Overall Dose
One of the most important practical advantages of pulsed infrared light therapy is that pulsing allows for higher peak power during each on-period without increasing the total energy dose over the full treatment session.
To understand this, consider a simple example. A continuous wave device operating at 100 mW delivers that power steadily throughout the session. A pulsed device can deliver peaks of 200 mW during each on-burst while maintaining an average power of 100 mW across the session by using a 50% duty cycle. The higher peak power during each pulse means more light energy is delivered in a concentrated burst, which improves tissue penetration and enhances cellular stimulation. The off-periods then prevent the overexposure effects that the same high power delivered continuously would risk.
This is the physical mechanism behind why pulsed light therapy achieves deeper penetration than continuous wave at the same average power level. Research by Salehpour showed that pulsed LED at 660nm and 850nm can penetrate deep enough to impact brain tissue and improve cognitive function. The implication for skin therapy is clear: if this approach reaches brain tissue, its penetration into dermal layers goes well beyond what continuous LED achieves.
Nutrient Uptake and the Breathing Cell Effect
A particularly compelling finding related to pulsed infrared light therapy comes from research by Sommer's team. They found that red light switched on and off alternately can expand and contract the microscopic interfacial water layers present in living cells. When the light is on, water within the cell expands slightly beyond the lipid bilayer at the cell membrane. When the light is off, it retracts. This breathing effect causes cells to draw in molecules from their immediate surroundings, including active skincare ingredients applied to the skin.
This mechanism is why Maysama pairs their pulsed LED devices with their Green Rooibos skincare range. The pulsed delivery is not just about light penetration; it is about making the skin more receptive to the bioactive compounds in the products used alongside therapy.
Pulsed Infrared Light and Melanin-Rich Skin
Another important advantage of pulsed delivery is its benefit for darker skin tones. Research by Brondon tested pulsed light with melanin filters in place and found that pulsed light was better able to penetrate melanin-rich skin than continuous wave. At a pulse frequency of 100 Hz, cell proliferation was at its maximum across the frequencies tested (ranging from 6 to 6000 Hz).
Continuous LED therapy in the red wavelength range has some potential for overstimulating melanocytes in darker skin tones, which can aggravate conditions like melasma. The off-periods in pulsed delivery allow the skin surface to cool between pulses, reducing the risk of surface overheating and melanocyte overstimulation. This makes pulsed infrared light therapy a more appropriate option for a wider range of skin types. Maysama's approach to pulsed LED therapy and skin tone management goes into further detail on this.
The AURA Mask: Non-Continuous Pulsed Light in a New Format
Maysama's upcoming AURA mask brings their pulsed delivery approach to a new product form. The AURA uses non-continuous, pulsed light, consistent with their Intelligent Micro-pulsing Technology (IMPT) across their existing device range. Rather than delivering a steady beam of infrared light, the AURA creates the same rhythmic on-off pattern that the science supports for enhanced cellular response.
Maysama's current lineup, including the PRANA LED Light Therapy Mask and the Pulse40 LED Light Therapy Panel, already uses pulsed delivery across their devices. The AURA adds to this range with a device built specifically around the facial mask format and the pulsed approach that distinguishes Maysama from brands using continuous wave technology.
What to Look For in a Pulsed Light Therapy Device
When evaluating pulsed infrared light therapy devices, several parameters matter beyond the simple fact that the light pulses:
Pulse frequency affects the biological response. Lower frequencies generally allow more cooling between pulses, which is beneficial for sensitive or melanin-rich skin. Frequencies around 100 Hz have shown particular efficacy for cell proliferation.
Duty cycle determines the balance between on and off periods, which in turn affects both peak power during pulses and the total energy delivered per session.
Irradiance (power density at the skin surface) matters for ensuring enough energy reaches target tissue. Maysama's PRANA mask, for example, has an irradiance of 45 mW/cm², higher than many consumer masks, enabling effective biostimulation even in pulsed mode.
Wavelength choice remains fundamental. The best documented wavelengths for skin applications are in the 630-680 nm red range and the 810-850 nm near-infrared range.
Conclusion
Pulsed infrared light therapy represents a more sophisticated approach to photobiomodulation than simply applying continuous light. The biological evidence shows that pulsing optimizes cellular response, avoids the ROS buildup that limits continuous treatments, enables higher peak power for deeper penetration, and creates conditions for better nutrient uptake in treated tissue. For at-home users, it can mean more effective treatments within the same session time.
If you are interested in exploring pulsed LED technology, take a look at Maysama's collection of LED beauty devices.
