Abstract
Levothyroxine is a synthetic T4 hormone that is biochemically and physiologically identical to the natural hormone, and it is used when the body is deficient in the natural hormone. This study was conducted to summarize the current evidence that compare evidence supporting morning dose to evening dose of levothyroxine in patients with hypothyroidism.A simple systematic review was carried out, searching databases PubMed, Google Scholar, and EBSCO. The authors extracted the needed data. There is conflicting data regarding effectiveness of morning dose versus evening dose in management of levothyroxine. More studies reported effectiveness of bedtime dose more than breakfast dose in hypothyroidism management. Numerous studies reported effectiveness of bedtime dose more than breakfast dose in hypothyroidism management. The most resent evidences recommended that, if possible, L-T4 be consistently taken either 60 minutes before breakfast or at bedtime (3 or more hours after the evening meal), for optimal, consistent absorption.