As parents and caregivers, we’re constantly seeking gentle, non-invasive ways to support children’s brain health—especially as emerging therapies offer promising alternatives for neurodevelopmental challenges. One such innovation gaining traction is photobiomodulation (PBM), a therapy that uses low-power red to near-infrared (NIR) light to stimulate biological processes in the brain. But with the brain undergoing critical maturation during early childhood and adolescence, a pressing question remains: Is PBM safe for the developing brain?

A groundbreaking 2025 study published in Lasers in Medical Science (PMC12497671) sets out to answer this vital question, and its findings offer reassuring insights for anyone interested in pediatric brain health. Let’s dive into what this research reveals—and why it matters for the future of childhood neurotherapy.

What Is Photobiomodulation, and Why Is It Gaining Attention?

First, let’s break down the basics: PBM is a non-invasive technique that delivers red or NIR light (typically 600–1000 nm) to tissues, where it interacts with mitochondrial enzymes to boost energy production, reduce inflammation, and support cellular repair. For the brain, this means potential benefits like improved cognitive function, reduced oxidative stress, and enhanced neuroplasticity—making it a promising tool for conditions like autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and Down syndrome.

While PBM has been studied extensively in adults and even shown to aid recovery from stroke, traumatic brain injury, and age-related cognitive decline, research on its safety in children and adolescents has been limited. The developing brain is uniquely sensitive: its neural circuits are still forming, and glial cells (the brain’s “support system” and immune responders) play a critical role in shaping healthy development. Could PBM disrupt this delicate balance by triggering inflammation or glial overactivity?

The Study: Testing 810 nm PBM in Young Rats

To address this gap, a team of researchers from institutions across Spain (including the Instituto de Neurociencias del Principado de Asturias and the University of Oviedo) designed a preclinical study to evaluate the safety of 810 nm PBM—a wavelength commonly used in transcranial therapies—in developing brains.

Using healthy juvenile male Wistar rats (equivalent to early childhood in human development), the researchers focused on two key markers of neuroinflammation:

1. Glial cell reactivity: Astrocytes and microglia are glial cells that respond to stress or injury by becoming “reactive”—a process linked to inflammation. The team measured levels of GFAP (a marker for astrocyte activation) and Iba1 (a marker for microglia activation) in the prefrontal cortex and hippocampus, two brain regions critical for cognition, emotion, and memory.
2. Pro-inflammatory cytokine expression: Cytokines like interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor α (TNF-α) are signaling molecules that drive inflammation. The researchers used quantitative PCR to measure their mRNA levels in the same brain regions.

The rats received 810 nm PBM therapy for 5 consecutive days (following 2 days of habituation), with parameters mirroring clinical use: 40 mW output power, 65.6 W/m² irradiance, and a daily fluence of 46.5 J/cm². A control group underwent the same procedure but with the PBM device turned off (sham treatment), and a third group remained undisturbed.

The Results: No Signs of Neuroinflammation

Here’s the breakthrough: After analyzing the rats’ brains on postnatal day 29 (the end of the study period), the researchers found no evidence of harmful neuroinflammatory responses.

• Glial cell density (measured via GFAP and Iba1 immunohistochemistry) was identical across the PBM, sham, and control groups. There was no increase in reactive astrocytes or microglia in the prefrontal cortex or hippocampus—meaning PBM didn’t trigger glial overactivity.
• Levels of pro-inflammatory cytokines (IL-6, IL-1β, TNF-α) showed no significant differences between the PBM and sham groups. The therapy did not upregulate these inflammation markers in either brain region.

In short: Under the tested parameters, 810 nm PBM did not disrupt the developing brain’s homeostasis or trigger unwanted immune responses.

Why This Matters for Kids and Caregivers

For families navigating neurodevelopmental challenges, this research is a game-changer. Here’s why:

• Preliminary safety proof: The study provides the first preclinical evidence that 810 nm PBM does not induce neuroinflammation in the developing brain. This is a critical first step toward validating its use in pediatric populations.
• Hope for targeted therapies: Children with ASD, ADHD, or other neurodevelopmental disorders often face limited non-pharmaceutical options. PBM’s non-invasive nature (no surgery, no drugs) makes it an attractive alternative—especially if safety is confirmed.
• Building on clinical promise: Previous clinical studies have already shown that PBM can improve behavior, attention, and cognitive function in children with ASD and ADHD. This new research reinforces that these benefits may come without the risk of inflammatory side effects.

What’s Next?

While this study is reassuring, the researchers emphasize that more work is needed. The study focused on male rats at a specific developmental stage and used a single set of PBM parameters (wavelength, fluence, duration). Future research should explore:

• Safety across different ages (from infants to adolescents)
• Sex differences in response (since the brain develops differently in males and females)
• Long-term effects (beyond the immediate post-treatment period)
• Varied PBM parameters (e.g., different wavelengths, session frequencies)

For now, though, this study (available in full at PMC12497671) offers a hopeful foundation. It suggests that when used appropriately, 810 nm PBM could be a safe tool to support the developing brain—opening doors for more targeted, child-friendly therapies in the years to come.

Final Thoughts

As research into PBM advances, it’s clear that the therapy’s potential extends far beyond adult populations. For parents, clinicians, and researchers alike, this 2025 study is a key milestone: it addresses a major safety concern and paves the way for further exploration of PBM as a gentle, effective option for children’s brain health.

If you’re interested in learning more about the science behind these findings, we encourage you to read the full study here: Safety of 810 nm photobiomodulation in the developing brain: no evidence of glial reactivity or pro-inflammatory cytokine expression in rats. It’s a fascinating deep dive into the intersection of neuroscience and innovative therapy—one that could shape the future of pediatric care.