Woman with dark hair pulling a white medical mask up to her face

Research on Light Therapy and Long COVID

Q: What results can be expected and when?

Types of results and their timelines vary depending on the individuals. However, a combination of research and anecdotal evidence from providers suggests some expected results to be the following: improved language capabilities, improvements in emotional regulation, decreased repetitive behaviours, and improved social skills/engagement. While some clients may see results very quickly, others may take a few months.

Q: What is mitochondrial dysfunction?

Mitochondrial dysfunction is a term that encapsulates dysfunction in various operations of the mitochondria. With mitochondria being the main energy producers of the cell, dysfunction can lead to reduced ATP (energy) production, increased oxidative stress, and difficulty maintaining healthy cell function. When mitochondria can’t keep up with the body’s energy demands or fail to remove damaged components, it can affect brain function, muscle strength, immune response, and overall vitality. Mitochondrial dysfunction is linked to many conditions, including fatigue, neurodegeneration, and metabolic disorders (Zong et al., 2024).

Q: How many PBM sessions will I need?

Benefits can often be noticed within a few sessions, especially related to sleep and mental clarity. For cognitive improvements, consistent use over several weeks or months is typically recommended. As AD is often referred to as a neurodegenerative disease with genetic components, incorporating light therapy as a regular lifestyle habit can support overall brain health and give your brain the best chance to stay at its most performing level over time.

Q: Is PBM safe?

Yes. PBM is FDA-cleared for various applications and has a strong safety profile. It’s non-invasive, painless, and has no known serious side effects when used as directed.

Long COVID can arise from a variety of causes and often lead to symptoms that disrupt daily functioning. Fortunately, emerging research on transcranial photobiomodulation (tPBM) shows promising potential in supporting recovery from this condition.

Woman adjusting eyeglasses, wearing striped shirt with manicured nails

Signs and Symptoms of Long COVID

People can develop long COVID symptoms even if they never experienced any symptoms during their initial COVID-19 infection. These symptoms may also appear weeks or even months after the person has seemingly recovered. While Long COVID impacts people differently, some common symptoms include:

Extreme tiredness, especially after activity
Problems with memory, often called brain fog
A feeling of being lightheaded or dizzy
Problems with taste or smell
Sleep problems
Shortness of breath
Cough
Headache
Fast or irregular heartbeat
Digestion problems, such as loose stools, constipation or bloating

Biomarkers of Long Covid

Tracking Long COVID Biomarkers
Over 113 biomarkers are associated with Long COVID, including cytokine/chemokine, biochemical, vascular, and neurological markers (Lai et al., 2023).
Inflammation and Lasting Symptoms
Various inflammatory markers, such as interleukin-6, tumor necrosis factor α, and interferon-γ–induced protein-10 have been associated with Long COVID symptoms (Peluso et al., 2022).
Brain Fog and the Blood–brain Barrier
Alterations in the functionality of the blood brain barrier is seen to be associated with brain fog in Long COVID patients (Greene et al., 2024).

Abstract illustration with illuminated particles and flowing light waves on blue background

What Causes Symptoms of Long COVID?

While the causes of Long COVID are still under investigation, researchers have a few theories for what can cause this condition (Mayo Clinic, 2024)

The virus responsible for COVID-19 can disrupt communication within the immune system, potentially causing immune cells to misidentify the body’s own cells as harmful and attack them - a response known as an autoimmune reaction.
COVID-19 can reactivate dormant viruses that remain in the body.
The virus upsets the gut’s ecosystem.
The virus may persist in the gut and potentially spread.
The virus impacts the cells lining the blood vessels.
The virus disrupts communication in the brainstem or in the vagus nerve, which regulates the body’s automatic functions.

Improvement in Cognitive Function
Mitochondrial dysfunction is highly implicated in individuals with Long COVID, causing impaired energy production in the cell that leads to chronic fatigue (Molnar et al., 2024). A main mechanism of PBM is increased ATP production, which can recalibrate energy deficits in people with Long COVID (Hamblin, 2017).
See the study
Motor and Cognitive Improvements
Research on PBM has been seen to improve various symptoms associated with Long COVID, such as motor function, memory performance, and processing speed (Dougal, Ennaceur & Chazot).
See the study

COVID-19 Brain Fog

Authors:: Robert Bowen & Praveen Arany
Published:: April 5, 2023
Sample size:: 14 (n=7 tPBM, n=7 full body PBM)

In a study by Bowen and Arany (2023), 12 sessions of 14 minutes of using the Neuradiant 1070 resulted in an improvement in cognitive tests including working memory, executive function, mental flexibility and reaction time. These findings were similar to the findings using a full body PBM bed, suggesting that reduction in Long COVID symptoms can be generated with a more affordable and portable tPBM device.

Read the full publication

Methods

Participants & Duration:

Two groups of seven individuals with Long COVID symptoms, including brain fog, underwent a four-week treatment consisting of 12 sessions per participant.

Interventions

Transcranial PBM (tPBM): 1070 nm LED helmet (Neuradiant 1070). Whole-Body PBM (wbPBM): NovoTHOR light bed emitting 660 nm and 850 nm wavelengths.

Assessments (pre- and post-12 sessions):

Montreal Cognitive Assessment (MoCA)
Digit Symbol Substitution Test (DSST)
Trail Making Tests A & B
Physical Reaction Time (PRT)
Quantitative EEG (WAVi system)

Results

Cognitive Improvements:

Both PBM modalities were associated with statistically significant improvements on cognitive tests (p < 0.05).

EEG Changes:

Quantitative EEG (WAVi) measurements showed changes that supported the observed cognitive benefits.

Similar Efficacy for Both Methods:

Improvements were seen whether PBM was delivered transcranially or via whole-body light, suggesting various PBM delivery methods may benefit Long COVID brain fog.

Pre-Post PBM Usage Tests

Graph C shows the pre and post light therapy protocols. In both groups we see an increase in the MoCA score, with a higher score meaning less impaired cognitive function.

Bar graph labeled DSST showing completion scores for Pre-PBM and Post-PBM conditions under tPBM and wBPM, with asterisks indicating significance

We can see in the Ddigit symbol substitution test (DSST) there is also an improvement from the baseline test to after the light therapy was applied.

This graph shares a clear indication that after patients received tPBM in particular there was a reduction in time it took to complete the task, showing clear cognitive processing improvements.

FAQs

What results can be expected and when?

Types of results and their timelines vary depending on the individuals. However, a combination of research and anecdotal evidence from providers suggests some expected results to be the following: improved language capabilities, improvements in emotional regulation, decreased repetitive behaviours, and improved social skills/engagement. While some clients may see results very quickly, others may take a few months.

What is mitochondrial dysfunction?

Mitochondrial dysfunction is a term that encapsulates dysfunction in various operations of the mitochondria. With mitochondria being the main energy producers of the cell, dysfunction can lead to reduced ATP (energy) production, increased oxidative stress, and difficulty maintaining healthy cell function. When mitochondria can’t keep up with the body’s energy demands or fail to remove damaged components, it can affect brain function, muscle strength, immune response, and overall vitality. Mitochondrial dysfunction is linked to many conditions, including fatigue, neurodegeneration, and metabolic disorders (Zong et al., 2024).

How many PBM sessions will I need?

Benefits can often be noticed within a few sessions, especially related to sleep and mental clarity. For cognitive improvements, consistent use over several weeks or months is typically recommended. As AD is often referred to as a neurodegenerative disease with genetic components, incorporating light therapy as a regular lifestyle habit can support overall brain health and give your brain the best chance to stay at its most performing level over time.

Is PBM safe?

Yes. PBM is FDA-cleared for various applications and has a strong safety profile. It’s non-invasive, painless, and has no known serious side effects when used as directed.

References

Bowen, R., & Arany, P. R. (2023). Use of either transcranial or whole-body photobiomodulation treatments improves COVID-19 brain fog. Journal of Biophotonics, 16(8), e202200391. https://doi.org/10.1002/jbio.202200391

Dougal, G., Ennaceur, A., & Chazot, P. L. (2021). Effect of transcranial near-infrared light 1068 nm upon memory performance in aging healthy individuals: A pilot study. Photobiomodulation, Photomedicine, and Laser Surgery, 39(10), 654–660. https://doi.org/10.1089/photob.2020.4956

Hamblin, M. R. (2017). Mechanisms and applications of the anti-inflammatory effects of photobiomodulation. AIMS Biophysics, 4(3), 337–361. https://doi.org/10.3934/biophy.2017.3.337

Greene, C., Connolly, R., Brennan, D., Laffan, A., O'Keeffe, E., Zaporojan, L., O'Callaghan, J., Thomson, B., Connolly, E., Argue, R., Meaney, J. F. M., Martin-Loeches, I., Long, A., Ni Cheallaigh, C., Conlon, N., Doherty, C. P., & Campbell, M. (2024). Blood–brain barrier disruption and sustained systemic inflammation in individuals with long COVID-associated cognitive impairment. Nature Neuroscience, 27(3), 421–432. https://doi.org/10.1038/s41593-024-01576-9

Lai, Y.-J., Liu, S.-H., Manachevakul, S., Lee, T.-A., Kuo, C.-T., & Bello, D. (2023). Biomarkers in long COVID-19: A systematic review. Frontiers in Medicine, 10, Article 1085988. https://doi.org/10.3389/fmed.2023.1085988

Molnár, T., Lehóczki, A., Fekete, M., Várnai, R., Zavori, L., Erdő-Bonyár, Sz., Simon, D., Berki, T., Csecsei, P., & Ezer, E. (2024). Mitochondrial dysfunction in long COVID: Mechanisms, consequences, and potential therapeutic approaches. GeroScience, 46(5), 5267–5286. https://doi.org/10.1007/s11357-024-01165-5

Peluso, M. J., Sans, H. M., Forman, C. A., Nylander, A. N., Ho, H., Lu, S., Goldberg, S. A., Hoh, R., Tai, V., Munter, S. E., Chenna, A., Yee, B. C., Winslow, J. W., Petropoulos, C. J., Martin, J. N., Kelly, J. D., Durstenfeld, M. S., Hsue, P. Y., Hunt, P. W., Greene, M., Chow, F. C., Hellmuth, J., Henrich, T. J., Glidden, D. V., & Deeks, S. G. (2022). Plasma markers of neurologic injury and inflammation in people with self-reported neurologic postacute sequelae of SARS-CoV-2 infection. Neurology: Neuroimmunology & Neuroinflammation, 9(5), e200003. https://doi.org/10.1212/NXI.0000000000200003

Mayo Clinic Staff. (2024, August 23). Long COVID: Lasting effects of COVID-19. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/coronavirus-long-term-effects/art-20490351