Integrating transcranial photobiomodulation into chiropractic care could enhance therapeutic outcomes and expand treatment options, offering your patients a more comprehensive and innovative approach to healing.
Transcranial photomodulation with near-infrared light has emerged as a promising noninvasive therapy for many disorders. By applying low-level light in the range of 800–1,100nm to the scalp, t-PBM penetrates the skull and modulates neuronal activity in the underlying cortical regions. This approach enhances neuronal metabolism, triggers anti-inflammatory and antioxidant responses and supports neurogenesis and synaptogenesis.1,2 Both lasers and light-emitting diodes (LEDs) have been employed as light sources in clinical settings.2 T-PBM’s safety, affordability and accessibility distinguish it as a neuromodulation method with considerable therapeutic potential.
The goal of this article is to provide a concise overview of recent advances and emerging evidence on transcranial photobiomodulation. It will review the proposed biological mechanisms, summarize findings from clinical studies across different populations, evaluate safety and tolerability and discuss the implications and limitations for clinical practice.
How transcranial photobiomodulation works
The therapeutic basis of t-PBM is grounded in its impact on mitochondrial and vascular function. Experimental studies show stimulation improves mitochondrial membrane potential, electron availability for oxygen reduction and adenosine triphosphate (ATP) synthesis, while regulating reactive oxygen species.1 These effects are mediated through the absorption of photons by cytochrome c oxidase (CCO), the terminal enzyme of the mitochondrial respiratory chain, which enhances oxidative metabolism and boosts energy production.
Nitric oxide release represents another central mechanism. By promoting vasodilation through calcium-activated potassium channels, nitric oxide contributes to improved cerebral blood flow and oxygenation, effects that have been observed in healthy adults following stimulation. In turn, these hemodynamic changes support secondary processes, such as neuroplasticity and neuronal connectivity.1,3 Both tissue culture and animal studies confirm t-PBM upregulates CCO activity, accelerates cortical ATP production and modulates inflammatory pathways. Collectively, these mechanisms provide a strong rationale for the observed improvements in sleep, wakefulness, cognition and mood regulation.3
Clinical applications and emerging evidence
Neurodevelopmental disorders
A systematic review of preclinical and clinical studies investigated t-PBM in neurodevelopmental disorders, including autism spectrum disorder (ASD), attention-deficit hyperactivity disorder (ADHD) and Down syndrome (DS). Across these conditions, improvements were reported in disruptive behavior, social communication, sleep, attention, motor skills and verbal fluency. The proposed mechanisms involve mitochondrial enhancement, oxidative stress modulation and attenuation of neuroinflammation. Reported side effects were minimal. However, the authors emphasized the need for larger sham-controlled trials with biomarker analyses to optimize parameters and better understand the pathways of action.1
Mild cognitive impairment and neurodegeneration
Near-infrared (NIR) t-PBM has recently emerged as a potential therapy for various neurodegenerative conditions, including memory issues. In older adults with mild cognitive impairment (MCI), a randomized, double-blind, placebo-controlled trial demonstrated t-PBM significantly improved cognition measured by the Montreal Cognitive Assessment, with benefits persisting for three months. These improvements were accompanied by increased levels of brain-derived neurotrophic factor (BDNF), suggesting effects on neuroplasticity. No changes were observed in mood or neurodegeneration biomarkers, but the findings support t-PBM as an adjunctive approach in the prevention of neurodegenerative decline.4
Substance use and mood disorders
Beyond cognition, t-PBM has shown efficacy in psychiatric and addiction-related conditions. A randomized controlled trial in patients undergoing methadone maintenance treatment found significant reductions in depression, anxiety and opioid craving among participants receiving active stimulation compared with sham. These improvements were sustained at one- and three-month follow-ups, underscoring both efficacy and durability.5
Neurological function and brain activity
Systematic reviews indicate even a single t-PBM session can influence brain activity in healthy individuals, with measurable increases in regional cerebral blood flow and changes in neural connectivity. Both focal and helmet-based stimulation approaches were capable of eliciting vascular and neuronal responses. In patients with neurological conditions, findings remain preliminary but suggest possible improvements in cerebral perfusion and functional connectivity. The reviews highlighted the heterogeneity in stimulation protocols and called for more randomized controlled trials to establish consistent outcomes.6
Regarding sleep and wakefulness, another systematic review concluded t-PBM may enhance wakefulness, cognition and memory consolidation, particularly in individuals with chronic fatigue or sleep disturbances. Still, the authors noted the need for studies incorporating objective sleep measures and standardized treatment parameters.3
Cognitive enhancement and brain injury
In a systematic review of 35 studies evaluating t-PBM in cognitive function, 82.9% reported improvements, including positive outcomes in mild cognitive impairment, dementia and traumatic brain injury (TBI). However, fewer than half of the clinical trials were randomized controlled designs, and one Phase III trial in stroke patients was terminated for lack of statistical significance, pointing to the necessity of further investigation.7
In chronic TBI, a systematic review of six studies identified improvements in cognition, cerebral blood flow and functional connectivity. Yet, variability in application protocols limited the ability to recommend specific treatment parameters.8 Complementary evidence from a randomized trial in mild TBI patients demonstrated improvements in visual working memory, verbal learning, sleep quality, pain and post-concussion symptoms following t-PBM, with changes reaching clinically meaningful thresholds. No such benefits were observed in the sham condition.9
The NeuroThera Effectiveness and Safety Trial (NEST-1) provided early evidence of t-PBM in acute ischemic stroke. This multicenter, randomized, double-blind trial showed treatment initiated within 24 hours of onset was safe and suggested preliminary efficacy in improving outcomes. While promising, confirmatory large-scale studies are required.10
Safety and tolerability in clinical use
Safety data on t-PBM are encouraging. A study2 of patients with major depressive disorder treated twice weekly for eight weeks observed side effects, such as headache, dizziness, altered taste and transient changes in appetite or blood pressure. These events were generally mild, transient and not significantly different from sham. No serious adverse events were reported, and the overall metabolic and hemodynamic profile was benign.2
A more recent analysis11 evaluated safety across different doses of NIR t-PBM. No significant associations between dose and adverse event rates were identified, and changes in weight or blood pressure were clinically insignificant. The side-effect profile remained benign regardless of dosimetry, reinforcing the overall tolerability of the intervention. The absence of adverse outcomes in functional near-infrared spectroscopy, which also employs NIR light, further supports the safety of this approach.11
Final thoughts
The evidence for transcranial photobiomodulation has expanded substantially in recent years, with studies reporting benefits across neurodevelopmental disorders, cognitive impairment, psychiatric conditions, brain injury and stroke. Its mechanisms, enhanced mitochondrial function, nitric oxide-mediated vasodilation and neuroplasticity, offer a compelling biological rationale for these effects.
For DCs, these findings highlight an emerging, noninvasive modality that can complement existing strategies for neurological and psychiatric care. Although limitations, such as small sample sizes, heterogeneous protocols and short follow-up periods remain, the consistently favorable safety profile and accessibility of t-PBM justify its careful integration into practice. Current evidence supports its use as a complementary approach, while ongoing research will refine treatment parameters and further clarify its role in patient care.
Francisco Cidral, ND, MSC, PHD, POSTDOC, is the founder and CEO of Scientifica Consulting. He holds a master’s degree and PhD in neurosciences and a postdoctorate in health sciences. Cidral is a professor of integrative medicine and neurophysiology, with a specialization in laser acupuncture and photobiomodulation. He has authored more than 35 scientific publications and books. Cidral is a board member of various scientific journals and international research groups. He can be contacted at cidral@scientificaconsulting.com.
This article was written on behalf of Avant Wellness. For more information, visit avantwellness.com.
References
Coelho DRA, et al. Transcranial photobiomodulation for neurodevelopmental disorders: A narrative review. Photochem Photobiol Sci. 2024;23:1609–1623. https://pubmed.ncbi.nlm.nih.gov/39009808/. Accessed September 12, 2025.
Cassano P, et al. Reported side effects, weight and blood pressure, after repeated sessions of transcranial photobiomodulation. Photobiomodul Photomed Laser Surg. 2019;37(10):651-656. https://pubmed.ncbi.nlm.nih.gov/31647774/. Accessed September 12, 2025.
Gaggi NL, et al. Enhancing sleep, wakefulness and cognition with transcranial photobiomodulation: A systematic review. Front Behav Neurosci. 2025;19:1542462. https://pubmed.ncbi.nlm.nih.gov/40822571/. Accessed September 12, 2025.
de Oliveira BH, et al. Transcranial photobiomodulation increases cognition and serum BDNF levels in adults over 50 years: A randomized, double-blind, placebo-controlled trial. J Photochem Photobiol B. 2024;260:113041. https://pubmed.ncbi.nlm.nih.gov/39423445/. Accessed September 12, 2025.
Helali H, et al. The effectiveness of transcranial photobiomodulation therapy (tPBM) on reducing anxiety, depression, and opioid craving in patients undergoingmethadone maintenance treatment: A double-blind, randomized, controlled trial. BMC Psychiatry. 2025;25(1):94. https://pubmed.ncbi.nlm.nih.gov/39901090/. Accessed September 12, 2025.
Dole M, et al. A systematic review of the effects of transcranial photobiomodulation on brain activity in humans. Rev Neurosci. 2023;34(6):671-693. https://pubmed.ncbi.nlm.nih.gov/36927734/. Accessed September 12, 2025.
Lee TL, et al. Can transcranial photobiomodulation improve cognitive function? A systematic review of human studies. Ageing Res Rev. 2023;83:101786. https://pubmed.ncbi.nlm.nih.gov/36371017/. Accessed September 12, 2025.
Zeng J, et al. Can transcranial photobiomodulation improve cognitive function in TBI patients? A systematic review. Front Psychol. 2024;15:1378570. https://pubmed.ncbi.nlm.nih.gov/38952831/. Accessed September 12, 2025.
Lee TL, et al. Transcranial photobiomodulation improves cognitive function, post-concussion, and PTSD symptoms in mild traumatic brain injury. J Neurotrauma. 2025. https://pubmed.ncbi.nlm.nih.gov/40485299/. Accessed September 12, 2025.
Lampl Y, et al. Infrared laser therapy for ischemic stroke: A new treatment strategy: Results of the NeuroThera Effectiveness and Safety Trial-1 (NEST-1). Stroke. 2007;38(6):1843-1849. https://pubmed.ncbi.nlm.nih.gov/17463313/. Accessed September 12, 2025.
Coelho DRA, et al. Dose-dependent tolerability and safety of transcranial photobiomodulation: A randomized controlled trial. Lasers Med Sci. 2025;40(1):248. https://pubmed.ncbi.nlm.nih.gov/40437278/. Accessed September 12, 2025.
