Berisha-Muharremi V. et al. - Photobiomodulation in Chronic Autoimmune Thyroiditis: A Systematic Review

This systematic review identified only six clinical studies in humans evaluating photobiomodulation for chronic autoimmune thyroiditis, published between 2010 and 2025. The authors describe encouraging findings but conclude that randomized controlled trials comparing the treatment to a placebo are still needed before any clinical application.

What this study measured

This is a narrative systematic review, conducted in accordance with the PRISMA reporting guidelines, and not a clinical trial. The authors searched PubMed/MEDLINE, Google Scholar, and other databases to identify original human clinical studies evaluating photobiomodulation—also known as low-intensity laser therapy—in chronic autoimmune thyroiditis, including studies using the term “Hashimoto’s thyroiditis.”

Only studies reporting thyroid-related outcomes were included. Due to the heterogeneity of study designs and light exposure protocols, no quantitative synthesis was performed; the results are presented in narrative form.

Key Findings

The review does not provide any aggregated numerical results. The data below are those reported by the authors.

• 6 eligible clinical studies published between 2010 and 2025
• Reductions in thyroid autoantibodies reported in the included studies
• Improvements in Thyroid Hormone Levels
• Reductions in Levothyroxine Requirements
• Ultrasound Changes in Studies with the Longest Follow-Up Periods
• 1 controlled trial against a placebo: improvement in markers of oxidative stress and quality of life, with no short-term endocrine changes

The summary does not include any effect sizes, confidence intervals, or p-values. The lighting parameters used are not specified.

How photobiomodulation works for this indication

The mechanisms discussed remain hypothetical. Red or near-infrared light is thought to be absorbed by mitochondrial cytochrome c oxidase, which could increase ATP production in the exposed cells. In thyroid tissue, this mechanism could be accompanied by a modulation of the inflammatory response, as well as effects on local vascularization and oxidative stress. These hypotheses have not been proven and do not support the conclusion that there is an effect on the autoimmune process itself.

Limits You Should Know

The evidence base is very limited. Only six human studies were included over a 15-year period, with heterogeneous photobiomodulation protocols that make comparisons difficult. The authors note the frequent use of co-interventions such as selenium or vitamin D, which prevents the observed changes from being attributed solely to light. The only controlled trial against an inactive device did not show any short-term endocrine changes. The authors themselves indicate that randomized controlled trials are required before any clinical application.

What This Means in Practice

Nothing, at this stage. Chronic autoimmune thyroiditis is a condition that requires regular endocrinological follow-up, including blood tests and adjustments to medical treatment. Levothyroxine should never be stopped, reduced, or changed without medical advice, regardless of how you feel. Photobiomodulation is not an approved treatment for this condition and does not replace any aspect of standard care. Any complementary approach must be discussed in advance with your endocrinologist or primary care physician.

Frequently Asked Questions

Can photobiomodulation replace levothyroxine?

No. There is no information in this review to support that. Levothyroxine is a hormone replacement therapy prescribed and monitored by a doctor, and stopping or reducing the dose without medical advice can lead to serious consequences. Only the doctor who monitors your test results can decide whether to adjust your dose.

Why do the authors refer to "limited evidence"?

This is because only six human clinical studies met the criteria, and their protocols differed significantly from one another. Several of these studies also included selenium or vitamin D, making it impossible to isolate the specific effect of light. No pooled numerical results could be calculated.

What does a controlled test against an inactive device mean?

This is a trial in which some of the participants, without knowing it, receive a device that looks identical but does not emit active light. This makes it possible to distinguish the treatment’s intrinsic effect from the placebo effect and from spontaneous improvement. In this review, only one trial of this type was identified, and it did not show any short-term endocrine changes.

Reference

Berisha-Muharremi V, Humolli A. Photobiomodulation Therapy in Chronic Autoimmune Thyroiditis: A Systematic Review of Molecular Mechanisms and Clinical Applications. Int J Mol Sci, 2026;27(7):3007. PMID 41977196. DOI 10.3390/ijms27073007. https://doi.org/10.3390/ijms27073007

This summary is provided for informational purposes only and does not constitute medical advice. Photobiomodulation is not a substitute for prescribed treatment. Consult a healthcare professional.