Toronto, Ontario, Jan. 08, 2026 (GLOBE NEWSWIRE) -- A new breakthrough study from the Rotman Research Institute at Baycrest, University of Toronto (Motsenyat et al., Brain Stimulation 2025) shows that brief sessions of pulsed photobiomodulation (PBM) can measurably boost cerebrospinal fluid (CSF) flow – a core driver of the brain’s glymphatic waste-clearance system. The glymphatic pathway normally “drain[s] away waste metabolic products and soluble proteins such as amyloid-beta,” and its failure is linked to Alzheimer’s and Parkinson’s disease. As Dr. Jean Chen notes, PBM used “to enhance brain health, specifically glymphatic drainage…may make it a promising therapeutic tool against neurodegenerative diseases such as Alzheimer’s disease”. In other words, improving CSF clearance by light therapy could help clear toxic proteins and support healthy brain aging.
Glymphatic Clearance and Neurodegeneration
The glymphatic system – a network of CSF and interstitial fluid channels – serves as the brain’s “waste clearance pathway,” continuously flushing out toxins, debris and metabolic waste. Animal and imaging studies show that when glymphatic flow slows, amyloid and other neurotoxic proteins accumulate. Impairment of glymphatic (meningeal lymphatic) drainage has been observed in both Alzheimer’s and Parkinson’s models and is even described as a “final common pathway” across multiple neurodegenerative diseases. By contrast, augmenting this clearance could be protective: a recent review emphasizes that PBM “can serve as a non-invasive neuroprotective strategy for maintaining and optimizing effective brain waste clearance”. In short, there is growing scientific consensus that enhancing CSF flow may help counteract the neurotoxic waste accumulation implicated in dementia, traumatic brain injury, and other chronic brain disorders.
Baycrest Study: PBM Rapidly Increases CSF Flow
The Baycrest team tested whether PBM could directly modulate CSF dynamics in healthy adults. Using functional MRI, they found that just 4 minutes of low-level NIR light induced immediate changes in brain fluid movement. Key findings include:
- Rapid CSF modulation: A brief (4-min) PBM session caused a surge in intracranial CSF volume and a corresponding drop in net CSF inflow.
- Dose-dependent effects: Both forehead (transcranial) and nostril-based (intranasal) PBM showed stronger CSF effects at higher irradiances, with a clear “wavelength–irradiance interaction”.
- Skin pigment matters: Forehead PBM responses were melanin-dependent – lighter-skinned subjects showed larger CSF increases than darker-skinned volunteers. (This highlights a relative limitation of scalp-based PBM.)
- Intranasal efficiency: Crucially, PBM delivered through the nostril (Vielight’s patented approach) produced the same CSF-modulating effect as forehead PBM using only a small fraction of the power. In the authors’ words, intranasal PBM caused “a significant change in CSF dynamics…equivalent to forehead tPBM…with a small fraction of the irradiance”.
The authors suggest that these results support the hypothesis that PBM can transiently raises intracranial pressure to push CSF out (as a vasodilatory response increases CSF volume), thereby increasing the transport of toxins and waste out of the brain. Notably, the intranasal approach sidesteps the melanin effect: the study found no dependence on skin pigmentation for the nostril-based treatment. In practical terms, iPBM is much more consistent across individuals than scalp PBM.
Vielight’s Intranasal PBM: Precision and Efficiency
Vielight’s devices use precisely this nostril-based PBM. The Company’s patented intranasal applicator places an 810 nm LED in each nostril, delivering NIR light directly to capillaries and the olfactory region. This approach has several advantages over full-head light helmets:
- High Energy Efficiency: Because the light enters directly through the nasal mucosa, very little power is wasted. The Baycrest study showed that iPBM at ~1/20 the irradiance of a forehead LED produced the same glymphatic effect.
- Exact Dose Control: Intranasal LEDs emit a fixed, known power directly at the target tissue. This avoids the variability of helmet systems, where skull thickness, hair, and positioning can greatly affect delivery.
- Melanin-Independence: By bypassing the scalp, intranasal PBM is insensitive to skin tone. The Baycrest team notes that iPBM showed no melanin-related attenuation – addressing a known limitation of transcranial PBM.
- Targeted Glymphatic Access: Intranasal light reaches the brain base near the cribriform plate and olfactory bulbs – the very entry/exit points of the glymphatic flow.
“With a single nasal LED, we can focus light onto the olfactory/glymphatic interface – something a standard helmet simply cannot do,” explains Dr. Jean Chen.
“We have long hypothesized that the intranasal channel offers a direct route to the brain’s recovery systems, and it is gratifying to see this confirmed by the rigorous imaging protocols at Baycrest,” says Dr. Lew Lim, Founder and CEO of Vielight. “This research validates that our patented intranasal technology is not just about convenience, but about superior optical efficiency – achieving significant physiological modulation with a fraction of the energy required by transcranial-only methods. It effectively democratizes the therapy by ensuring consistent dose regardless of a person’s hair density or skin tone.”
Why 810 nm? Evidence Favors Near-Infrared
Vielight’s Neuro Duo and Neuro Pro use 810 nm (in addition to 40 Hz pulsing, etc.), and the Baycrest findings help explain why this is effective. Separate Monte Carlo simulations have shown that, for transcranial delivery, 810 nm light deposits more energy in prefrontal cortical regions than 1064 nm under equivalent conditions. In fact, in the Baycrest group’s recent optical modeling study, 810 nm yielded the highest cortical energy among the wavelengths tested, whereas 1064 nm could potentially outperformed at the nostril source. This suggests that 810 nm is the choice for activating superficial to mid-depth brain regions transcranially.
The choice of 810 nm is also supported by photobiology: this wavelength aligns well with the absorption spectrum of cytochrome c oxidase (the mitochondrial “light receptor”) and has been widely used in PBM brain research, while the mechanisms of 1064 nm or 1070 nm are less understood.
Conclusion
In summary, the Baycrest study provides strong, real-time evidence that PBM can directly modulate brain fluid flow – an effect with broad implications for neurology, sports medicine, and healthy aging.
Media Contacts
Media Contacts: For more information, interviews, or product demos, please contact Vielight’s scientific communications team.
About Vielight
About Vielight: Vielight, Inc. develops photobiomodulation (PBM) devices for brain and whole-body health and is the world leader in transcranial PBM. The patented intranasal 810 nm PBM modules in the Neuro Duo/Pro systems leverage peer-reviewed science to deliver targeted neural therapy. Vielight provided the PBM devices and partial funding for this study as part of an industry-academic partnership aimed at validating non-invasive neurotechnologies. The study design, data analysis, and publication were conducted independently by the Rotman Research Institute, University of Toronto to ensure scientific objectivity.
Sources
Sources: Baycrest Research (Motsenyat et al., 2025) and related peer-reviewed literature support the claims in this release. The Vielight device specifications and patents are publicly available; product efficacy and safety have been tested in independent studies.
Attachments
Dominic Lim Vielight Inc. dominic@vielight.com
