The Role of Inositol in Thyroid Physiology and in Subclinical Hypothyroidism Management

Front Endocrinol (Lausanne). 2021 May 10:12:662582. doi: 10.3389/fendo.2021.662582. eCollection 2021.


Myo-Inositol (MYO) is the most abundant stereoisomer of inositols' family, cyclic polyols with 6 hydroxyl groups. Myo-Inositol has a relevant role in thyroid function and autoimmune diseases, as a precursor of phosphoinositides that takes part in the phosphatidylinositol (PI) signal transduction pathway. Among phosphoinositides, phosphatidylinositol 4,5- bisphosphate (PIP2) is the precursor of inositol triphosphates (IP3), second messenger of several hormones including thyroid-stimulating hormone (TSH). As a second messenger in the phospholipase C (PLC)-dependent inositol phosphate Ca2+/DAG pathway, Myo-Inositol is essential to produce H2O2 required for the synthesis of thyroid hormones. Consequently, depletion of Myo-Inositol or impaired inositol dependent TSH signaling pathway may predispose to the development of some thyroid diseases, such as hypothyroidism. Many clinical studies have shown that after treatment with Myo-Inositol plus Selenium (MYO+Se), TSH levels significantly decreased in patients with subclinical hypothyroidism with or without autoimmune thyroiditis. The TSH reduction was accompanied by a decline of antithyroid autoantibodies. Moreover, Myo-Inositol supplementation seemed to be involved also in the management of thyroidal benign nodules, with a possible effect in the size reduction. This review proposes a summary of the role of inositol, especially of Myo-Inositol, in the thyroidal physiology and its contribution on the management of some thyroid diseases.

Keywords: TSH; myo-inositol; subclinical hypothyroidism; thyroid dysfunctions; thyroid hormones.

Publication types

  • Review

MeSH terms

  • Humans
  • Hypothyroidism / drug therapy*
  • Hypothyroidism / metabolism
  • Hypothyroidism / pathology
  • Inositol / administration & dosage*
  • Thyroid Function Tests
  • Thyroid Gland / drug effects*
  • Thyroid Gland / metabolism
  • Thyroid Hormones / metabolism*
  • Vitamin B Complex / administration & dosage*


  • Thyroid Hormones
  • Vitamin B Complex
  • Inositol