Melatonin, a hormone that regumagnesium citrate in the morninglates sleep-wake cycles, has gained significant popularity as a dietary supplement for improving sleep quality and managing circadian rhythm disorders. The regulatory status of melatonin varies liquid calcium citratewidely across the globe, reflecting differences in public health policies, scientific assessments of safety and efficacy, and cultural attitudes towards supplemnew chapter calcium citrateents. This article explores the regulatory frameworks governing the use of melatonin in macitracal d petitesjor health supcalcium citrate chewsplement markets, including the United States, the European Union, Canada, Australia, China, Japan, and Singapore.