*This statement summarizes the third USPSTF recommendations for screening for chlamydial infection and the supporting scientific evidence, and it updates the 1995 recommendations contained in the Guide to Clinical Preventive Services, second edition (1).
Older adults may be more sensitive to the side effects of this drug, especially fast/pounding/irregular heartbeat. Current information shows that this drug may be used during pregnancy. Tell your doctor if you are pregnant because your dose may need to be adjusted. Levothyroxine passes into breast milk but is unlikely to harm a nursing infant.
A: Usually, when taking levothyroxine the side effect is weight loss rather than weight gain. This occurs because the thyroid hormone is what regulates metabolism. If you are hypothyroid, your metabolism is slower since you don't have as much thyroid hormone in your body.: Levothyroxine is a synthetic or man-made replacement for a hormone that is normally produced by the thyroid gland to regulate the body's energy and metabolism. It is used to treat hypothyroidism (low thyroid hormone levels) and to treat and prevent goiter (an enlarged thyroid gland).