Photobiomodulation for Long COVID: A Review of the Current State of Knowledge

Millions of people around the world are living with symptoms that persist long after the initial infection. Extreme fatigue, brain fog, and an irregular heartbeat: Long COVID takes hold in the body and in daily life, often defying conventional treatments. Photobiomodulation, with its red and near-infrared light wavelengths, is attracting growing interest as a way to support the well-being of those affected.

Long COVID: A Syndrome with Many Faces

Long COVID, or post-COVID syndrome, is defined as the persistence of post-infectious symptoms beyond twelve weeks after the acute phase. It does not present as a single clinical picture: some individuals report debilitating fatigue, others suffer from severe cognitive impairments, and still others experience disturbances in the autonomic nervous system.

Among the most well-documented symptoms is postural orthostatic tachycardia syndrome (POTS). This syndrome is characterized by an abnormal increase in heart rate when a person moves from a lying to a standing position, causing dizziness, tachycardia, and extreme fatigue during physical exertion. For people affected by long COVID, POTS is one of the most debilitating symptoms of post-COVID syndrome.

Brain fog is another hallmark symptom: difficulty concentrating, trouble finding the right words, and a feeling of mental sluggishness. These cognitive impairments affect individuals who were otherwise active before the infection, and their impact on both professional and personal life is significant.

Inflammatory markers remain elevated in some individuals with long COVID, suggesting that chronic inflammatory mechanisms contribute to the persistence of symptoms. Mitochondrial dysfunction—that is, the inability of cells to produce sufficient energy—has also been highlighted in several recent studies.

How does photobiomodulation affect these mechanisms?

Photobiomodulation (PBM) involves exposing tissues to specific wavelengths of low-intensity red light (between 630 and 700 nm) and near-infrared light (between 800 and 1100 nm). This light penetrates the cells and interacts with a component of the mitochondrial respiratory chain, cytochrome c oxidase, thereby stimulating the production of ATP, the molecule that supplies energy to cells.

This mechanism of action is particularly relevant in the context of long COVID. If extreme fatigue and low energy are partly due to mitochondrial dysfunction, then stimulating cellular energy production is a promising approach to helping improve the well-being of those affected.

In addition, red light therapy sessions have a modulating effect on inflammatory processes. Several studies have shown that low-intensity photobiomodulation helps reduce inflammatory markers in exposed tissues. For individuals experiencing long COVID with persistent inflammation, this aspect is of significant interest.

Functional neurology offers another approach: transcranial photobiomodulation, which involves applying light directly to the skull, aims to support cerebral microcirculation and improve neuronal function. Preliminary research is exploring this approach to help manage brain fog and cognitive impairments associated with long COVID.

What the studies say about photobiomodulation and long COVID

Scientific data on the use of photobiomodulation specifically for long COVID is beginning to accumulate, although research is still in its early stages.

A study published in 2022 in *Photobiomodulation, Photomedicine, and Laser Surgery* evaluated the effect of red and near-infrared light sessions on individuals experiencing post-COVID symptoms. The results showed an improvement in fatigue and a reduction in certain inflammatory markers after several weeks of exposure. The authors emphasize the need for further research with larger sample sizes but conclude that this is a promising avenue.

Other studies have focused more specifically on cognitive impairments. Transcranial photobiomodulation, which has already been explored in conditions such as Alzheimer’s disease and traumatic brain injury, shows promising effects on mental clarity and concentration. When applied to the cognitive impairments associated with long COVID, it represents an avenue that several research teams in functional neurology are beginning to explore in earnest.

With regard to the autonomic nervous system and postural orthostatic tachycardia syndrome, some clinical observations report a gradual improvement in heart rate and better exercise tolerance in individuals who have undergone regular photobiomodulation sessions. These findings have yet to be confirmed by controlled studies, but they are generating interest within the scientific community.

It should be noted that research on post-COVID is still in its early stages. The syndrome itself was only recently described and named, and studies on the subject are still ongoing. Photobiomodulation is part of a landscape in which several approaches are being explored simultaneously.

Which symptoms of long COVID can photobiomodulation help manage?

Without claiming to offer a universal solution, the areas in which photobiomodulation appears best positioned to contribute to the well-being of individuals with long COVID are as follows:

• Extreme fatigue and low energy: by stimulating ATP production at the mitochondrial level, red light therapy sessions can help support cellular energy metabolism, which is often impaired in post-COVID patients.
• Cognitive impairment and brain fog: Transcranial photobiomodulation aims to improve cerebral blood flow and support neural function, with observed benefits for concentration and mental clarity.
• Inflammatory symptoms: Modulating inflammatory processes using low-intensity wavelengths can help manage discomfort associated with pain and chronic fatigue.
• Exercise tolerance: Some individuals with orthostatic tachycardia syndrome report a gradual improvement in their exercise capacity following regular exercise sessions.

Everyone's journey is unique, and guidance from a qualified professional is essential to tailor the sessions to each person's specific needs.

Frequently Asked Questions

Is photobiomodulation suitable for people with long COVID?

Photobiomodulation is a non-invasive wellness approach that uses low-intensity red and near-infrared light wavelengths. It has no major contraindications for individuals with long COVID, except in specific situations that should be evaluated on a case-by-case basis. Its excellent tolerability makes it an accessible option for supporting the management of post-COVID symptoms.

How many sessions are needed to see results?

Available studies and feedback suggest that a minimum of several weeks of regular sessions is necessary to observe effects on fatigue, cognitive function, or heart rate. The frequency and duration of sessions vary depending on the individual and the specific wellness goals.

Does photobiomodulation help with the brain fog associated with long COVID?

Transcranial photobiomodulation directly targets cerebral microcirculation and metabolism. Several studies in functional neurology have demonstrated positive effects on mental clarity and concentration. When applied specifically to the brain fog associated with long COVID, this approach is currently the subject of ongoing studies, the results of which are eagerly awaited.

Can POTS be improved through photobiomodulation?

The postural orthostatic tachycardia syndrome observed in some patients with long COVID involves a dysregulation of the autonomic nervous system. A few clinical observations report improvements in heart rate and exercise tolerance. These findings require confirmation through controlled studies, but they represent a promising avenue of investigation.

Are there any contraindications for photobiomodulation?

Low-intensity photobiomodulation is generally well tolerated. However, certain precautions should be taken: avoid direct exposure of the eyes to the LEDs, avoid areas affected by specific medical conditions, and avoid use during pregnancy. Consulting with a professional beforehand ensures that sessions can be tailored safely.

Red light: an option worth exploring seriously

Long COVID poses ongoing challenges for millions of people, and the search for solutions to better manage daily symptoms remains a priority. Photobiomodulation, through its effects on cellular energy, inflammatory processes, and functional neurology, offers a complementary approach to well-being that research is beginning to document in earnest. While no definitive answers exist at this stage, the current state of research is encouraging, and future studies will provide more robust data to guide those affected.

See also:

• Applications of photobiomodulation
• Neurological and cognitive disorders
• An Introduction to Photobiomodulation
• Best Practices and Safety