Melatonin has been known for quite awhile and was originally thought to be a hormone that told the brain when to sleep.

Then researchers were surprised when they found that Melatonin was inside Mitochondria, the so called “power plants” of cells where the Melatonin concentration is 900% higher than in the brain. Inside mitochondria Melatonin is apparently used as an anti-oxident.

Then Japanese researchers found that after Melatonin tell the brain it is sleep time, each molecule of Melatonin splits into two chemicals, one of which is important in making long term memories.

So what else can Melatonin do?

Fight viruses like Covid-19 and Influenza in lung cells.....

https://medicalxpress.com/news/2021-01-melatonin-lungs-infection-coronavirus.html

sample quote

Melatonin synthesized in the lungs acts as a barrier against SARS-CoV-2, preventing expression of genes that encode proteins in cells such as resident macrophages in the nose and pulmonary alveoli, and epithelial cells lining the alveoli, all of which are entry points for the virus. The hormone, therefore, prevents infection of these cells by the virus and inhibits the immune response so that the virus remains in the respiratory tract for a few days, eventually leaving to find another host.

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A previous post in this thread was about Cleveland Clinic findings that their patients who were taking time release Melatonin had significantly lower Covid-19 infections, and this effect was greatest in Black males.