Doctors from the Medical University of Łódź said initial investigations into the effect of blue light on the reduction of COVID-induced fatigue and blood pressure normalisation are “promising”.

“In medicine, we often use light in therapy. For example, in dermatology, UV light is traditionally used in the treatment of psoriasis or atopic dermatitis,” said Professor Aleksandra Lesiak from the Department of Dermatology, Pediatric Dermatology and Oncology Clinic of the Medical University of Łódź. She added that blue light is also used in the treatment of skin diseases, due to its immunomodulating, anti-inflammatory and antipruritic effects.

The study focused on the use of blue light phototherapy to relieve the symptoms of post-COVID-19 syndrome. The syndrome was found in “patients who have had COVID-19, often with minor symptoms and without the need for hospitalisation, often complain of malaise, chronic fatigue, but also depressive symptoms, intermittent, ineffective sleep or insomnia, and muscle pain,” said Professor Joanna Narbutt, head of Department of Dermatology, Pediatric Dermatology and Oncology Clinic of the Medical University of Łódź.

So far, a dozen patients have completed the study, and another dozen are undergoing therapy, the results of which “are satisfactory,” Professor Narbut added.

The research conducted so far shows that blue light not only reduces inflammation by inhibiting the production of cytokines, but also reduces systolic blood pressure, improves the functions of endothelium (the layer of cells lining blood vessels) by stimulating the release of nitric oxide, and reduces arterial stiffness.

An important advantage of blue light is also that it increases the level of beta-endorphins in the body, which improve mood and thus contribute to a better quality of life. Thanks to them, patients cope better with stress, gain better immunity, and are more resistant to pain.

Dermatologists found that in previous studies the use of blue light is a safe method. This type of phototherapy does not cause side effects typical for UV radiation, such as an increased risk of skin and epidermis cell DNA damage and skin cancer. There is also no risk of skin burns.

“The only side effect observed so far may be a mild, temporary hyperpigmentation that subsides after the therapy is discontinued,” Professor Lesiak concluded.