Pulsation

Pulsation is a mode of red and infrared light therapy in which the light flashes at a precisely defined frequency - unlike flicker, it is an intentional and biologically beneficial phenomenon that enhances light penetration into deep tissues and strengthens the therapeutic effect.

Pulsation (also referred to as pulsed mode, pulsed wave, abbreviation PW) is a method of delivering light energy in which the light source alternates between on and off states at precisely defined intervals. The result is not a constant light output, but a series of light pulses with a measurable frequency (number of pulses per second, expressed in Hz) and duty cycle (the proportion of time the light is on relative to the total cycle).

Pulsation is one of the parameters of photobiomodulation that researchers have been intensively studying in recent years. Several studies indicate that a pulsed mode can be more effective than continuous wave in certain applications - especially in the treatment of deep tissues and in neurological indications. [R]

Pulsation vs. flicker: a key difference you need to understand

The most important thing to know about pulsation: pulsation and flicker are not the same, even though both describe light flashing.

Flicker is an undesirable, uncontrolled fluctuation of a light source caused by alternating current (50/60 Hz) or faulty electronics. The frequency of flicker typically corresponds to the mains frequency (50 Hz) and its multiples, and it is a parasitic effect rather than an intentional one. Flicker places strain on the nervous system, causes eye fatigue, headaches, and can disrupt hormonal balance.

Pulsation, on the other hand, is an intentional feature of a therapeutic device. The frequency, duty cycle, and pulse shape are precisely set by the manufacturer according to the therapeutic goal. Mitochondriak® devices are designed to eliminate flicker while enabling therapeutic pulsation - these are therefore two opposite concepts within a single device.

How pulsation works and why it is beneficial

The mechanism by which pulsed mode enhances the effects of photobiomodulation is being studied at multiple levels. So far, science has identified the following main factors:

1. Deeper tissue penetration
With pulsed light delivery, the peak power is higher than in continuous mode with the same average power. At a 50% duty cycle, the peak power is double the average. Higher peak power allows photons to overcome greater resistance from melanin and other tissue barriers, enabling light to reach deeper structures in the body. [R]

2. Reduced thermal load on tissue
Pulsing allows tissues to thermally recover during the periods when the light is off (the so-called quench period). As a result, the device can operate at higher peak power without the risk of overheating the skin - increasing therapeutic effectiveness while maintaining safety.

3. Resonant biological frequencies
Biological systems have their own oscillatory frequencies at both cellular and organ levels. Research suggests that pulsation at certain frequencies may resonate with these natural rhythms, thereby amplifying the biological response. A study on human dental pulp stem cells (810 nm, 38 mJ/cm²) showed that a frequency of 300 Hz prolonged delayed luminescence patterns and increased alkaline phosphatase activity - indicating a direct dependence of biological response on pulsation frequency, not just total delivered energy. [R]

4. Modulation of nitric oxide (NO)
Pulsed light delivery influences the binding and release patterns of nitric oxide (NO) in Cytochrome C oxidase and hemoglobin. Altered timing of NO release may be responsible for some specific effects of pulsed mode that do not occur with continuous light-particularly in vasodilation and neuroprotective effects. [R]

Key frequencies and their effects

Not every pulsation frequency produces the same biological effect. Research has identified several frequencies with well-documented outcomes:

10 Hz
The 10 Hz frequency is one of the most extensively studied. A study using 810 nm pulsed NIR light (50% duty cycle) found that 10 Hz was more effective than both continuous mode and 100 Hz frequency in wound healing-it reduced inflammatory markers (NF-kB, TNF-alpha), increased Cytochrome C oxidase activity, and raised ATP levels in cells. In neurological research, a study found that pulsed NIR laser at 10 Hz was as effective as the antidepressant citalopram in treating depressive states in an animal model. [R]

40 Hz
The 40 Hz frequency corresponds to gamma brain oscillations-electrical activity that is significantly reduced in patients with Alzheimer’s disease. Transcranial photobiomodulation at 40 Hz is currently the subject of active clinical research in relation to cognitive decline and neurodegenerative disorders.

1–2 Hz
Low frequencies in the range of 1 to 2 Hz have demonstrated strong stimulation of cell proliferation, alkaline phosphatase activity, and bone nodule formation in in vitro studies-indicating potential in bone tissue regeneration.

Continuous mode (CW — Continuous Wave)
Continuous mode without pulsation is the standard for superficial applications, skin, and cosmetic use. It is easier to operate and provides consistent energy delivery to surface tissues. For deep tissue and neurological applications, research is increasingly favoring pulsed mode.

Pulsation in Mitochondriak® devices

Mitochondriak® devices allow pulsation mode to be adjusted directly via a touchscreen display. Frequency and duty cycle are customizable parameters that can be tailored to your therapeutic goal. More details on specific settings can be found in the FAQ and in the device manual.

At the same time, even in continuous mode, Mitochondriak® devices are designed to eliminate unwanted flicker-parasitic fluctuations caused by power supply. Flicker-free design is a fundamental requirement for safe and comfortable use.

Related terms

Flicker - unwanted, uncontrolled fluctuation of a light source; the opposite of pulsation; harmful to the body, not beneficial
Duty cycle - the proportion of time the light is on relative to the total cycle; expressed as a percentage (e.g., 50% = light is on half the time)
Pulsation frequency - the number of pulses per second, expressed in Hz (hertz); determines the biological response of tissue
Peak power - maximum power during the “on” phase of a pulse; higher in pulsed mode than the average power in continuous mode
Continuous mode (CW) - uninterrupted delivery of light; an alternative to pulsed mode
Photobiomodulation - the scientific term for red and NIR light therapy, which may include pulsed mode
NIR - near-infrared light; when delivered in pulses, it penetrates deeper into tissues
ATP - cellular energy; its production can be enhanced more efficiently with optimal pulsation than with continuous light
Nitric oxide (NO) - a signaling molecule whose release is modulated by pulsation; responsible for part of the specific effects of pulsed mode

Frequently asked questions about pulsation

What is pulsation in red light therapy?

Pulsation is a mode in which a therapeutic device alternates the light on and off at a precisely defined frequency. The result is a series of light pulses instead of a continuous light output. Pulsation frequency is measurable (in Hz) and intentional-which fundamentally distinguishes it from flicker, which is unwanted and random fluctuation.

What is the difference between pulsation and flicker?

Pulsation is an intentional technological parameter of a therapeutic device. The frequency, duty cycle, and pulse shape are precisely set and biologically beneficial. Flicker, on the other hand, is an unwanted parasitic effect, usually at a frequency of 50 or 100 Hz (derived from mains power), which strains the nervous system and vision. High-quality therapeutic devices are flicker-free while enabling therapeutic pulsation—the exact opposite of flicker.

Is pulsed mode always better than continuous mode?

Not always. It depends on the therapeutic goal. For superficial applications (skin, cosmetic use, surface wounds), continuous mode (CW) is fully sufficient and well studied. Pulsed mode (PW) provides advantages mainly for deep tissues (joints, muscles, organs) and neurological applications, where higher peak power enables better penetration through tissue barriers.

What pulsation frequency should I use?

The choice depends on the therapeutic goal. A frequency of 10 Hz is the most studied for general recovery and deep tissues. A frequency of 40 Hz is researched in the context of cognitive function and gamma brain oscillations. Low frequencies (1 to 2 Hz) are suitable for bone tissue regeneration. For most home applications targeting joints, muscles, and overall health, we recommend following the device manual.

What is duty cycle?

Duty cycle expresses what percentage of the total pulse period the light is on. At a 50% duty cycle, the device emits light for half of the time and is off for the other half. At this ratio, peak power is double the average power. The lower the duty cycle, the higher the peak power—but also the shorter the actual exposure time. Most therapeutic protocols use a 50% duty cycle.

Can pulsation damage the eyes?

Flashing light in general can be uncomfortable for sensitive individuals, and at very high frequencies it may trigger adverse reactions in people with photosensitive epilepsy. For standard therapeutic use and recommended frequencies, pulsation in Mitochondriak® devices is not dangerous. During therapy, we recommend closing your eyes or using protective goggles, which eliminates the direct visual perception of flashing.

How do I know if my device uses pulsation?

Most home devices operate in continuous mode unless pulsation is explicitly stated in the specifications. Next-generation Mitochondriak® devices with touchscreen display allow you to set pulsation directly in the menu. At lower frequencies (for example 10 Hz), pulsation can be visually observed as slow flashing of the device.

Summary

Pulsation is an intentional therapeutic parameter of photobiomodulation, in which light flashes at a precisely defined frequency. Unlike harmful flicker, pulsation is biologically beneficial: it increases the depth of light penetration into tissues, reduces thermal load on the skin, modulates the release of nitric oxide, and at certain frequencies resonates with the natural biological rhythms of cells. A frequency of 10 Hz is one of the most well-studied and has been shown to improve tissue regeneration, increase CCO activity, and enhance ATP production. Next-generation Mitochondriak® devices support pulsation while simultaneously eliminating unwanted flicker.

Scientific studies and sources

Pulsed vs. continuous 810 nm laser - 10 Hz most effective in wound healing, increased CCO activity and ATP production. PMC. 2016. PMC5115773
Pulse frequency dependency on bioenergetics - 300 Hz increases mitochondrial activity in stem cells. PubMed. 2017. PMID: 29162863
Pulsed tPBM generates distinct neurocognitive effects vs. continuous wave. Lasers Med Sci. 2023. PMID: 37668791
Pulsed vs. continuous wave: deeper tissue penetration with reduced thermal load. Journal of Biophotonics. 2025. PMC12245496
Kashiwagi S et al. Photobiomodulation and nitric oxide signaling. Nitric Oxide. 2023. PMC9808891