Levothyroxine Use in the United States, 2008-2018.

Levothyroxine is one of the most commonly prescribed drugs in the US, with approximately 7% of the population estimated to have an active prescription.1,2 For nonpregnant adults with subclinical hypothyroidism (thyrotropin level elevated but ≤10 mIU/L and normal free thyroxine [FT4] levels), evidence consistently demonstrates no clinically relevant benefits of levothyroxine replacement for quality of life or thyroid-related symptoms.3,4 To better understand the use of levothyroxine in the US over time, we analyzed national data for commercially insured and Medicare Advantage enrollees. Identify all potential conflicts of interest that might be relevant to your comment. Conflicts of interest comprise financial interests, activities, and relationships within the past 3 years including but not limited to employment, affiliation, grants or funding, consultancies, honoraria or payment, speaker's bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued. Err on the side of full disclosure. If you have no conflicts of interest, check "No potential conflicts of interest" in the box below. The information will be posted with your response. Not all submitted comments are published. Please see our commenting policy for details.