Melatonin and Hyperthyroidism

Hyperthyroidism due to the excess release of thyroid hormones from the thyroid gland manifests various biochemical and clinical findings. It adversely affects the cardiovascular, urogenital, and endocrine systems; electrophysiological functions; and oxidative metabolism in various organs and tissues. The main function of melatonin, which is released from the pineal gland, is to regulate the circadian rhythm of the body. The aim of this review is to provide some general information about melatonin and thyroid hormones and review the effects of melatonin on the growth and function of the thyroid gland and hyperthyroidism. Several experimental studies have suggested the inhibitory effects of melatonin on the thyroid gland and its functions. Various methods have been used in these in vitro and in vivo studies, such as short- and long-term melatonin administration, light restriction to increase the activity of the pineal gland, and pinealectomy. Melatonin may directly or indirectly affect the thyroid gland and its functions; however, the underlying mechanisms are not yet fully elucidated. With its typical inhibitory effects on the thyroid gland and hormone secretion, as well as its antioxidant effects, it may be considered as a new option in the treatment of hyperthyroidism.

Cite this article as: Üstündağ H, Şentürk E, Gül M. Melatonin and Hyperthyroidism. Arch Basic Clin Res 2020; 2(2): 59-64.