Medically reviewed by Kelly Wood, MD Normal thyroid-stimulating hormone (TSH) levels generally fall between 0.5 and 5.0 milliunits per liter (mU/L). If your TSH level is higher than 5.0 mU/L it ...

Thyroid-stimulating hormone (TSH) tells your thyroid how much thyroid hormone to make. Your TSH levels can impact a variety of bodily functions.

Background: Small cross-sectional studies have suggested that metformin, a first-line oral hypoglycemic agent, may lower thyroid-stimulating hormone (TSH) levels. Our objective was to determine ...

Enrollment criteria were treatment for at least six months, stable l-thyroxine dosing 100-200 µg/day for at least two months, and TSH level 0.1-4.8 mU/L (J Clin Endocrinol Metab. 2006;91:2624-2630).

The study cohort had a mean levothyroxine daily dose of 132.4 µg. The mean TSH was 2.26 mU/L. Of the study cohort, 29.2% met their TSH target, with 50.4% overtreated and 20.4% undertreated.

TSH or thyroid-stimulating hormone (TSH) levels below 0.4mU/L indicate hyperthyroidism, while levels of about 4.0mU/L and above–hypothyroidism.