Transcranial Photobiomodulation

Fire! When you hold your hand near a fire, you feel its warmth. What's happening? The warmth you feel comes from the fire's infrared radiation, which your skin absorbs, stimulating your nerves to sense heat. Similarly, brain stimulation via transcranial photobiomodulation stimulates neuronal mitochondria, increasing cellular energy levels. This process modulates neuronal communication and brain waves by promoting neural synchronization and activity in targeted frequency ranges.

Alpha brainwaves represent the brain's resting state and are most prominent when your mind is meditative. These waves foster mental coordination, calmness, and inner peace. Alpha photobiomodulation can elevate neural alpha wave activity, enhancing relaxation and mental balance. In contrast, gamma brainwaves dominate when your mind is focused, attentive, and engaged in learning. They represent the brain's active state, where elevated gamma oscillations are associated with increased mental acuity and cognitive performance. Gamma photobiomodulation can boost neural gamma wave activity, supporting sharper focus and improved learning capabilities.

This isn't a novel or unstudied idea, pulsed near-infrared stimulation at specific frequencies has been shown in peer-reviewed human EEG research to produce measurable, frequency-specific brainwave changes, including work published in Scientific Reports (Nature) and ongoing research from multiple university bioengineering labs.

At Sleep and Brain, we address the challenges of delivering near-infrared light energy (810–1100 nm) to the brain by overcoming obstacles like hair, scalp, and tissue. We use wavelengths within the body's optical window (800–1100 nm), which penetrate human tissue effectively. Among these, we focus on 810 nm, a wavelength with the lowest absorbance by tissue, blood, and water, making it ideal for brain stimulation. The 810 nm wavelength penetrates deeply, targeting mitochondria to boost adenosine triphosphate production, reduce oxidative stress, and regulate reactive oxygen species, enhancing cellular function. It also promotes neurogenesis, supporting the formation of new cortical neurons, while its anti-inflammatory properties are being studied for their potential to reduce neuroinflammation and support brain healing.

To ensure maximum energy delivery, we position the LEDs directly with the scalp, minimizing distance and preventing energy loss caused by the inverse square law of light. We also use advanced LED lens technology to bypass hair, which can be a significant barrier by trapping and absorbing light. By combining the optimal wavelength, direct LED-to-scalp contact, and hair-bypassing technology, we ensure effective and precise delivery of near-infrared red energy into the brain.

Achieving the optimal irradiance level is essential to ensure effective brain photobiomodulation. We use up to 400 mW/cm² of irradiance, the concentration of light energy delivered at the surface. Sufficient irradiance is critical for near-infrared light to penetrate the skin and skull. Photobiomodulation research has consistently shown a dose-response relationship rather than a simple "more is better" one — too little light under-stimulates tissue, but too much can be counterproductive. Our irradiance levels are set within the range used in published human tPBM research to stay in the effective window. Our system's irradiance ensures the light energy reaches the intended regions effectively, enabling superior outcomes for brain health while remaining within safe limits.

In addition to scalp sites, Sleep and Brain uses intranasal photobiomodulation to deliver near-infrared energy through the nose, targeting the brain's underside. This method directly stimulates the olfactory bulb, which connects to brain regions responsible for long-term memory storage and reaches the ventromedial prefrontal cortex, a key area for cognition.

Photobiomodulation is generally very well-tolerated. The most common experience during a session is mild warmth or a gentle scalp sensation, most people find it relaxing. A few things we screen for before starting:

  • Photosensitizing medications: certain antibiotics, retinoids, and some psychiatric medications can increase light sensitivity.

  • Photosensitivity conditions: conditions such as lupus or porphyria may warrant extra caution.

  • Eye protection: given the light intensities involved, protective eyewear is used during sessions, particularly with modules positioned near the eyes or with the intranasal applicator.

We'll review your medical history during your consultation to confirm you're a good candidate.

A typical session lasts approximately 20 minutes, and most patients complete a course of 6 sessions per week over eight weeks, though this is tailored to your individual protocol and goals. Sessions are relaxing and require no downtime — you can resume normal activities immediately afterward.

At Sleep and Brain, we avoid using transcranial photobiomodulation helmets. Helmets fail to address hair as a barrier, with their inflexible dome shape causing significant energy loss through absorption by hair. They are also rigid and cannot adapt to different head sizes and shapes, increasing the distance between the light source and the scalp, which leads to rapid energy loss due to the inverse square law of light. Furthermore, helmets often rely on numerous weak LEDs, which generate high total power but insufficient irradiance, leaving the light energy too weak to penetrate the scalp effectively. Finally, helmets lack proper ventilation, leading to heat buildup, discomfort, and reduced practicality.

Sleep and Brain tailors photobiomodulation to optimize brain connectivity to ensure balanced neural network enhancement for cognitive and emotional well-being. We provide targeted neural stimulation by focusing on specific brain networks or comprehensive neural stimulation by engaging all networks simultaneously. In addition to standard alpha and gamma protocols, we utilize advanced features like cross-frequency coupling, frequency sweeps, and neural network synchronization.

We utilize the Gracefire protocols, developed through years of neurofeedback research, along with adjustable module positioning for precise targeting. We customize session parameters, including session length, power intensity, phase asynchrony, duty cycle, and frequency pulses ranging from 1 to 40 Hz. We activate modules in various combinations, including synchronized patterns, enabling personalized programs that meet diverse cognitive and neurological needs. This customization level is designed to support optimized outcomes for brain health.

Photobiomodulation devices, including the technology used here, are categorized by the FDA as low-risk general wellness devices. They are not FDA-cleared or approved to diagnose, treat, cure, or prevent any specific disease or condition. We offer this as part of a broader, individualized approach to brain health.

Frequently asked questions