Must Patients Take Levothyroxine on an Empty Stomach?

Guidelines recommend taking levothyroxine on an empty stomach 30 to 60 minutes before breakfast to optimize absorption, which can be challenging for patients. To find out whether an empty stomach is really necessary, researchers randomized 90 adults with stable, well-controlled hypothyroidism to take levothyroxine with breakfast (see Figure 1), with a 15% dose increase to account for expected reduced absorption, or to follow standard recommendations. The primary outcome was thyroid-stimulating hormone (TSH) stability, defined as two consecutive TSH measurements within the reference range and a maximum change of 1 mIU/L from baseline.