Light on Sleep: How Photobiomodulation Assists the Brain's Waste Removal Process

Light on Sleep: How Photobiomodulation Assists the Brain's Waste Removal Process

Sleep isn't just a time to rest; it's super important for our everyday life and how we feel overall. It affects almost every type of tissue and system in the body – from the brain, heart, and lungs to metabolism, immune function, mood, and disease resistance. [1] Despite its significance, many struggle to attain quality sleep, leading to challenges in different facets of their lives. In this blog, we will explore methods to enhance sleep, such as research-supported light therapy.


Good sleep for good health

Quality sleep is the cornerstone of a healthy life. Not getting enough quality sleep regularly raises the risk of many diseases and disorders - which range from heart disease and stroke to obesity and dementia. [2] Establishing a consistent daily schedule of good sleep can make a world of difference in our health and overall well-being.

Unfortunately, the reality is that poor-quality sleep is a widespread issue. Its repercussions extend beyond mere tiredness, impacting our thinking, learning, memory, and even physical movements. Furthermore, there is growing evidence that poor sleep can accelerate the progression of neurodegenerative disorders, such as Alzheimer’s Disease, and may play a role in the pathogenesis of the disease. [3]


Light therapy for sleep disorders and insomnia

Photobiomodulation, also known as light therapy, has emerged as a promising non-drug therapeutic option for improving sleep quality. Recent studies in animal models have shown that light therapy improves the function of the brain during sleep, stimulating the removal of toxic waste products into the venous system. [4

The process is facilitated by the activation of the glymphatic system, the brain's built-in waste disposal mechanism. Sufficient sleep plays a crucial role in effectively clearing fluid and waste from the brain through the glymphatic system, contributing to enhanced overall health and well-being. Moreover, it reduces the risk of developing various serious illnesses, including neurological and cardiovascular disorders. [4]


Understanding the Glymphatic System and the Impact of Sleep

Schematic diagram of the glymphatic system of the brain from
Figure 1: Schematic diagram of the glymphatic system of the brain from Lights at night: does photobiomodulation improve sleep?


The picture above explains how the brain cleaning system works. In (A), which is a normal situation, what happens is that fluid flows in the brain (like water in a sponge) and takes away waste, keeping the brain healthy.

(B) shows what happens when things go wrong (if your sleep is not the best). Here, the cleaning process slows down, and the flow becomes messy. This is a problem because waste piles up in the brain, causing issues like plaque formation and problems for nearby cells.

Finally, (C) includes an improved situation with a photobiomodulation approach. In these circumstances, photobiomodulation helps the cleaning process and reduces problems in the brain by opening channels that help fluid flow better, keeping the brain cleaner.


Unlocking the Potential of Photobiomodulation for Improved Sleep and Long-Term Wellness

Photobiomodulation has been shown recently to improve the clearance of fluid and toxic substances from both the periphery and the brain (as shown in Figure 1) [4]. It stands to reason that establishing and maintaining a healthy lymphatic system will improve people's sleep quality, overall health, and well-being, and postpone the onset of disease.

In essence, photobiomodulation enhances the brain's function during sleep, offering a potential solution to the challenges faced by those struggling with poor-quality sleep. This, in turn, could significantly contribute to improving the overall quality of sleep for many individuals. If successful, this approach has the potential to enhance the health and well-being of those grappling with sleep-related challenges.

As the research continues, photobiomodulation comes as an opportunity for people seeking alternatives to traditional sleeping drugs. By understanding the benefits of this non-pharmacological approach, we can develop new methods to improve sleep quality and, ultimately, promote long-term health and well-being.



[1] National Institute of Neurological Disorders and Stroke. Brain Basics: Understanding Sleep. Available Online:

[2] Wein, H. Ph.D. 2021. Good Sleep for Good Health. Available Online:

[3] Malhotra, R. M.D. 2019. Sleep & Neurodegenerative Disease. Available Online:,in%20pathogenesis%20of%20the%20disease

[4] Valverde, A., Hamilton, C., 2022. Lights at night: does photobiomodulation improve sleep? Available Online:

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