What Frequency Is Best for Red Light Therapy?
TL;DR
- Frequency in red light therapy refers to how many times per second the light pulses on and off, measured in Hertz (Hz). Continuous light has no frequency setting because it does not pulse.
- For most LED red light therapy applications, continuous mode is the most well-supported approach. The pulsed light research most commonly cited online comes primarily from laser studies where pulsing manages heat buildup, which is not the same issue with LEDs.
- Specific pulse frequencies do have documented applications. 10Hz has research support for pain management. 40Hz has a growing evidence base for neurological applications including Alzheimer's research through gamma frequency entrainment.
- What actually determines results is wavelength, irradiance, and consistency of use. These matter significantly more than whether a device pulses.
- StreamShop's class IIa medical grade panels offer pulse frequency control from 1 to 10,000 Hz per wavelength, covering both continuous and all documented pulse frequency protocols.
Frequency is one of the more confusing topics in red light therapy, partly because the term means different things depending on context. When people search for the frequency of red light therapy, they are usually asking one of two things: what Hz setting should they use on their device, or what is the actual physical frequency of red light as an electromagnetic wave?
This article answers both, explains where the pulsed light debate comes from, covers the specific frequencies that do have research support, and clarifies what the evidence actually says about what drives results.
The Two Different Meanings of Frequency
The Physical Frequency of Red Light
In physics, the frequency of light refers to how many wave cycles occur per second, measured in terahertz (THz). Red light sits within the visible spectrum at wavelengths of approximately 620 to 700nm, corresponding to a physical frequency of roughly 430 to 480 THz. Near-infrared light has longer wavelengths and correspondingly lower physical frequencies. This is a fixed property of the light itself, determined by its wavelength, and is not something you adjust on a device.
The Pulse Frequency of a Device
In the context of red light therapy devices, frequency refers to the pulse rate of the light, how many times per second the LEDs or laser diodes switch on and off, measured in Hertz (Hz):
- 1 Hz means the light pulses once per second
- 10 Hz means ten on/off cycles per second
- 40 Hz means forty on/off cycles per second
- Continuous wave light does not pulse at all. It simply remains on throughout the session
Most LED red light therapy panels operate in continuous mode by default. Some devices offer selectable pulse frequencies as an additional feature, and understanding when these are relevant is the most practically useful question for most users.
Where the Pulsed Light Debate Comes From
The concept of an optimal Hz setting for red light therapy is largely derived from laser research, which does not translate directly to LED devices. Lasers produce highly focused, coherent light that can generate significant heat in tissue when used continuously. Pulsing the laser allows heat to dissipate between pulses, preventing tissue damage while still delivering therapeutic energy. This is the primary reason pulsing was studied and adopted in laser therapy protocols.
LEDs produce incoherent, dispersed light that spreads evenly over a large area and generates far less heat than lasers. The heat management rationale for pulsing does not apply in the same way. For LED devices, continuous exposure ensures the maximum amount of light energy reaches tissue during the session. Pulsing an LED technically means the light is off for part of the session, reducing total energy delivered if session time is held constant.
There is currently no strong clinical evidence demonstrating that pulsed LED light produces superior therapeutic outcomes compared to continuous LED light for the conditions most commonly treated with red light therapy including skin health, muscle recovery, and joint pain. Continuous mode remains the most well-supported approach for these applications.
When Specific Pulse Frequencies Are Relevant
10 Hz for Pain Management
10 Hz is the most researched pulse frequency in photobiomodulation for pain applications. A 2019 study published in the Journal of Photochemistry and Photobiology found that pulsed near-infrared light at 10 Hz produced significantly greater reductions in pain and inflammation in an arthritis model than continuous wave light at the same total dose. For people using red light therapy specifically for pain management, 10 Hz is the most evidence-aligned pulse frequency available.
40 Hz for Neurological Applications
40 Hz gamma frequency stimulation has attracted significant research attention for neurological applications. A landmark 2016 study published in Nature by Iaccarino et al. found that 40 Hz flickering light reduced amyloid and tau pathology in Alzheimer's mouse models by entraining gamma oscillations in the brain. A 2021 review in the Journal of Alzheimer's Disease confirmed that 40 Hz stimulation reduced neuroinflammatory markers across multiple preclinical models. For people using red light therapy for cognitive support, brain health, or neurological conditions, 40 Hz pulse mode is the most scientifically grounded specific frequency setting currently available.
Nogier Frequencies for Targeted Protocols
Nogier frequencies (73 Hz, 146 Hz, 292 Hz, 584 Hz, 1168 Hz, 2336 Hz, and 4672 Hz) are seven pulse rates developed by French physician Dr Paul Nogier for auriculotherapy, each associated with a different tissue type. These have been incorporated into some red light therapy protocols, particularly in advanced medical grade devices with per-wavelength frequency control. The evidence base for Nogier-specific frequencies in LED photobiomodulation is less established than for 10 Hz and 40 Hz, but for practitioners and users wanting to explore structured pulse protocols, devices with the full frequency range provide the flexibility to do so. For more detail on this topic see our dedicated guide to Nogier frequencies and red light therapy.
What Actually Determines Red Light Therapy Results
Rather than focusing on frequency or Hz settings, the research consistently points to three factors that have the greatest impact on outcomes.
Wavelength
Wavelength determines which tissues the light reaches and what cellular processes it stimulates. Red at 630 to 660nm is most effective for skin health, collagen stimulation, wound healing, and surface applications. Near-infrared at 810 to 850nm penetrates deeper into muscle, joint, and subcutaneous tissue and is most relevant for recovery, pain, and inflammation. At 940nm, an additional affinity for water absorption may support circulatory effects. At 1060nm, the deepest available penetration is most relevant for chronic pain, bone density, and deep tissue applications.
Irradiance
Irradiance measures how much light energy reaches the skin surface, expressed in mW/cm². Higher irradiance delivers more energy to tissue in the same session time. Irradiance at your actual treatment distance is the relevant figure, not the device's rated irradiance at contact distance. A device delivering 175 mW/cm² at 15cm produces a fundamentally different therapeutic dose to one delivering 30 mW/cm² at the same distance, regardless of any other setting.
Consistency
Photobiomodulation works cumulatively. Sessions of 10 to 20 minutes, three to five times per week over several weeks, consistently outperform irregular or infrequent use regardless of device settings. Establishing a consistent protocol and sticking to it matters more than optimising Hz settings for most users.
StreamShop Devices With Pulse Frequency Control
StreamShop's class IIa medical grade panels offer the most comprehensive pulse frequency control available in any at-home device, covering both standard continuous mode and the full documented pulse frequency range for any application.
The SS300 Pro, SS450 Pro, SS200, and SS100 class IIa medical grade panels all deliver pulse frequency control from 1 to 10,000 Hz adjustable per wavelength, alongside continuous mode. This covers 10 Hz for pain protocols, 40 Hz for neurological applications, the full Nogier frequency range from 73 to 4,672 Hz, and any custom frequency within the range. Per-wavelength dimming from 1 to 100% allows each of the nine wavelengths to be independently adjusted for precise protocol matching across different therapeutic goals.
StreamShop's laser mat with 1064nm includes continuous mode, breathing mode, 10 Hz, and 40 Hz pulse options, covering the two pulse frequencies with the strongest independent research support in a full-body format.
Frequently Asked Questions
What Is the Frequency of Red Light Therapy?
In device terms, frequency refers to the pulse rate of the light measured in Hertz (Hz). Continuous light does not pulse and has no frequency setting. In physics terms, the frequency of red light as an electromagnetic wave is approximately 430 to 480 THz, determined by its wavelength. Most people asking this question are interested in the device setting rather than the physics definition.
What Is the Best Hz for Red Light Therapy?
For most LED applications, continuous mode is the most well-supported approach. For pain management specifically, 10 Hz has the strongest research support. For neurological applications including brain health and cognitive support, 40 Hz is the most evidence-aligned setting. For general skin health, muscle recovery, and anti-ageing applications, continuous mode is appropriate and no specific Hz setting provides a meaningful advantage.
Is Pulsed Red Light Better Than Continuous?
For LED devices, continuous light is generally considered more appropriate for most applications because it delivers more total energy to tissue per session. The research supporting pulsed light comes primarily from laser studies where pulsing manages heat. For specific applications like pain management (10 Hz) and neurological support (40 Hz), pulsed protocols have documented benefits. For general use, continuous mode is the right starting point.
What Is 40 Hz Red Light Therapy?
40 Hz red light therapy refers to pulsing the light on and off 40 times per second. This frequency corresponds to gamma brain wave oscillations, and a landmark 2016 Nature study found that 40 Hz flickering light reduced amyloid pathology in Alzheimer's mouse models through gamma entrainment. Devices with a 40 Hz pulse mode combine the standard mitochondrial photobiomodulation mechanism with this gamma frequency effect, making it specifically relevant for neurological and cognitive applications.
Does Frequency Affect Red Light Therapy Results?
For LED devices, frequency has less impact on results than wavelength, irradiance, and consistency of use for most applications. Choosing the right wavelengths for your goals and using a device with adequate irradiance consistently over several weeks produces better outcomes than optimising Hz settings. For specific applications including pain (10 Hz) and neurological support (40 Hz), frequency does add meaningful value on top of the standard continuous protocol.
What Are Nogier Frequencies in Red Light Therapy?
Nogier frequencies are seven pulse rates developed by Dr Paul Nogier for auriculotherapy: 73 Hz, 146 Hz, 292 Hz, 584 Hz, 1168 Hz, 2336 Hz, and 4672 Hz. Each is associated with a different tissue type. They have been incorporated into some advanced red light therapy protocols, particularly for practitioners using devices with per-wavelength frequency control. The evidence base is less established than for 10 Hz and 40 Hz but the full frequency range is available on StreamShop's class IIa medical grade panels. See our Nogier frequencies guide for more detail.