Is Red Light Therapy Safe for Your Brain? 5 Myths Doctors Want You to Know

Red light therapy (RLT), also known as photobiomodulation, is gaining popularity as a non-invasive tool for brain health, cognitive support, and mood improvement.

Yet, myths about its safety persist, sometimes discouraging people from exploring this promising therapy.

This article debunks five common misconceptions about RLT safety, drawing on current clinical research and expert opinion.

Table of Contents

Key Takeaways

Red light therapy is generally safe for the brain when used as directed with quality devices.
RLT uses non-UV wavelengths and does not cause DNA damage or burns.
Most reported side effects are mild and temporary, such as minor headaches or skin redness.
Device quality, dosing, and medical guidance are essential for safe and effective use.
Consult a healthcare professional before starting RLT, especially if you have neurological or photosensitive conditions.

Myth 1: “Red Light Therapy Is as Dangerous as UV Light or Tanning Beds”

The Facts:
Red light therapy uses specific red (630–700 nm) and near-infrared (700–1100 nm) wavelengths that do not emit ultraviolet (UV) radiation, which is responsible for sunburn and DNA damage. Unlike tanning beds, RLT does not cause skin cancer or burns when used appropriately¹. Clinical studies confirm that RLT is non-thermal and painless, with no evidence of DNA damage or carcinogenic effects².

Myth 2: “RLT Causes Harmful Side Effects on the Brain”

The Facts:
Most clinical trials report that RLT is well-tolerated, with side effects being rare and mild³. The most commonly reported reactions include:

Mild headaches
Temporary skin redness or irritation
Occasional eye strain (if eye protection is not used)

A controlled trial on patients with mild traumatic brain injury found no serious adverse events, and most participants experienced improved cognitive function and mood after transcranial RLT sessions⁴. A 2021 review concluded that RLT is a safe and convenient physical method for neurological applications, with a low risk of harm when protocols are followed⁵.

Myth 3: “RLT Interferes with Brain Medications or Makes Conditions Worse”

The Facts:
RLT is generally compatible with most medications and neurological conditions, but there are important exceptions. People taking photosensitizing drugs (such as lithium, certain antibiotics, or antipsychotics) may be at increased risk of light sensitivity or skin reactions⁶. Those with epilepsy, a history of skin cancer, or recent brain hemorrhage should consult a healthcare provider before starting RLT⁷.

A 2024 review found that RLT did not negatively interact with Parkinson’s medications or worsen symptoms in dementia patients, but highlighted the need for caution in individuals with light-sensitive conditions⁸.

Myth 4: “All Red Light Devices Are Equally Safe for the Brain”

The Facts:
Device quality and settings are critical for safety. FDA-cleared or medically certified devices are tested for wavelength accuracy, power output, and safety features⁹. Low-quality or uncertified devices may emit harmful wavelengths, deliver inconsistent power, or lack safety shut-offs, increasing the risk of side effects¹⁰.

For safe home use, choose a device that:

Emits wavelengths between 630–850 nm
Has adjustable intensity and built-in timers
Provides clear instructions and safety certifications

Myth 5: “Long-Term RLT Use Harms Brain Cells”

The Facts:
No clinical evidence supports the idea that RLT damages brain cells when used within recommended guidelines. On the contrary, studies suggest neuroprotective effects, including reduced oxidative stress, improved mitochondrial function, and enhanced neurogenesis¹¹. A 2021 review found that RLT may alleviate symptoms of neurodegenerative diseases and improve cognitive function without harmful long-term effects⁵.

A pilot study on chronic traumatic brain injury patients showed significant improvements in executive function and memory after 18 RLT sessions, with no evidence of cognitive decline or adverse neurological outcomes⁴.

Limitations and Considerations

While RLT is generally safe, it is not suitable for everyone. Avoid RLT if you:

Have a history of skin cancer or systemic lupus erythematosus
Are taking medications that increase photosensitivity
Have an active malignant tumor or recent brain bleed
Are an infant or wish to use RLT directly on the thyroid gland

Always use eye protection and avoid direct irradiation to the eyes. Some people may experience mild headaches, nausea, or insomnia if exposed to excessive intensity or duration. These effects are usually short-lived and resolve with proper dosing and rest⁶.

Conclusion

Red light therapy is considered safe for most adults when used as directed with high-quality devices and proper protocols. Myths about its dangers often stem from confusion with UV or laser therapies, but current evidence shows RLT is non-thermal, non-invasive, and carries a low risk of adverse effects. Device quality, appropriate dosing, and medical consultation are key to maximizing benefits and minimizing risks. As research continues, RLT is poised to become an increasingly valuable tool for brain and mental health.

References

Hamblin, M. R. (2019). Mechanisms and applications of photobiomodulation in the brain. Journal of Neurophotonics, 6(2), 021011. https://doi.org/10.1117/1.NPh.6.2.021011
Barret, D. W., & Gonzalez-Lima, F. (2013). Transcranial infrared laser stimulation produces beneficial cognitive and emotional effects in humans. Neuroscience, 230, 13–23. https://doi.org/10.1016/j.neuroscience.2012.11.016
Examine.com. (2024). Red Light Therapy: Up-to-date evidence. https://examine.com/other/red-light-therapy/
Naeser, M. A., et al. (2014). Significant improvements in cognitive performance post-transcranial, red/near-infrared light-emitting diode treatments in chronic, mild traumatic brain injury: open-protocol study. Journal of Neurotrauma, 31(11), 1008–1017. https://doi.org/10.1089/neu.2013.3244
Wang, X., et al. (2021). Light therapy: a new option for neurodegenerative diseases. Frontiers in Neuroscience, 15, 799001. https://doi.org/10.3389/fnins.2021.799001
Occupational Therapy Brisbane. (2024). Red Light Therapy For Neurological Conditions Explained. https://occupationaltherapybrisbane.com.au/red-light-therapy-for-neurological-conditions-explained/
Salehpour, F., et al. (2024). Photobiomodulation therapy for sleep disturbances. Neurophotonics, 10(1), 011507. https://doi.org/10.1117/1.NPh.10.1.011507
Saltmarche, A. E., et al. (2017). Significant improvement in cognition in mild to moderately severe dementia cases treated with transcranial and intranasal photobiomodulation: Case series report. Photomedicine and Laser Surgery, 35(8), 432–441. https://doi.org/10.1089/pho.2016.4227
U.S. Food & Drug Administration. (2024). Medical Devices: Laser Products and Instruments. https://www.fda.gov/medical-devices/laser-products-and-instruments
Xie, Y., et al. (2024). Red light therapy for insomnia: A systematic review and meta-analysis. Sleep Medicine Reviews, 69, 101763. https://doi.org/10.1016/j.smrv.2023.101763
Salehpour, F., et al. (2023). Photobiomodulation therapy for traumatic brain injury: A systematic review. Neurophotonics, 10(1), 011507. https://doi.org/10.1117/1.NPh.10.1.011507