Impact of Photobiomodulation on T3/T4 Ratio and Quality of Life in Hashimoto Thyroiditis

Photobiomodul Photomed Laser Surg. 2020 Jul;38(7):409-412. doi: 10.1089/photob.2019.4740. Epub 2020 Mar 18.


Objective and background: Hashimoto's thyroiditis (HT) is both a B cell- and T cell-mediated, organ-specific autoimmune disease. No current treatment for underlying pathological mechanisms is available for HT and once diagnosed it requires long-term levothyroxine (LT4) treatment in most patients. The aim of our study was to evaluate the effects of photobiomodulation (PBM) on HT patients regarding thyroid functions, thyroid autoantibody levels, and decrease in hormone replacement needs. Methods: A total of 350 patients, who were diagnosed with Hashimoto`s thyroiditis, were included in our study. Patients were classified into two groups. Group 1 (n = 210) received PBM and dietary supplementation such as vitamin D, iron, and selenium. Group 2 (n = 140) received dietary supplements only. Patients' needs for LT4 replacement levels, triiodothyronine (T3), thyroxine (T4), and TSH levels, T3/T4 ratio, and thyroid autoantibody levels were evaluated. Results: As we compare both groups, the increase in T3 levels and T3/T4 ratio was markedly superior in Group 1 (p = 0.0001). The decrease in thyroid peroxidase antibody (TPO Ab) levels was also significantly different between both groups (p = 0.0001). Hormone replacement needs were also significantly decreased in Group 1 compared with Group 2 (p = 0.03). Low-level laser therapy (LLLT) is 70 times more effective in increasing T3/T4 ratio (p = 0.001) and 15 times more effective in decreasing levothyroxine dosage. Conclusions: Our results are encouraging and PBM seems to be very effective in increasing T3/T4 ratio and decreasing TPO Ab levels and weekly dosages of LT4 replacement therapy. Anti-inflammatory properties of PBM are greatly responsible for these changes and PBM causes major improvements in HT-related symptoms of the patient.

Keywords: Hashimoto thyroiditis; autoimmune thyroiditis; photobiomodulation.

MeSH terms

  • Adult
  • Cohort Studies
  • Dietary Supplements
  • Female
  • Hashimoto Disease / therapy*
  • Humans
  • Low-Level Light Therapy*
  • Male
  • Middle Aged
  • Quality of Life
  • Thyrotropin / blood
  • Thyroxine / blood*
  • Triiodothyronine / blood*


  • Triiodothyronine
  • Thyrotropin
  • Thyroxine