* For TSH suppression, Synthroid is used to help decrease levels of TSH in your body. TSH is made when your body needs thyroid hormones. A lower TSH level means your body doesn't need thyroid hormones as much as a higher TSH level indicates.

Does levothyroxine make TSH go up or down?

If the TSH is not at the desired goal, the levothyroxine dose can be adjusted up or down. TSH values that are slightly out of range may be corrected by a single dose increment or decrement, such as increasing from 100 to 112 μg or decreasing from 175 to 150 μg.

How long does it take for Synthroid to lower TSH?

A: Synthroid (levothyroxine) treats hypothyroidism, or low thyroid hormone levels. It can take several weeks to feel the effects of Synthroid on your symptoms. Doctors typically wait six weeks or so before adjusting your Synthroid dosage.