Melatonin is a hormone synthesized in your pineal gland and several other organs, indeed in most cells, including human lung monocytes and macrophages, as it is actually synthesized in your mitochondria. While most well-known as a natural sleep regulator, melatonin also has many other important functions. Notably, it plays an important role in cancer prevention and may prevent or improve certain autoimmune diseases, such as Type 1 diabetes. It also has anticonvulsant and antiexcitotoxic properties, and is a potent antioxidant with the rare ability to enter your mitochondria, where it helps prevent mitochondrial impairment, energy failure and the death of mitochondria damaged by oxidation. It also: Boosts immune function Helps recharge glutathione (and glutathione deficiency has been linked to COVID-19 severity) May improve the treatment of certain bacterial diseases, including tuberculosis Helps regulate gene expression via a series of enzymes As noted in the Journal of Critical Care: “Melatonin is a versatile …