Interesting, I hadn't heard anything about melatonin in regards to covid before this.

"Melatonin Affects Thrombosis, Sepsis, and COVID Mortality Rate"

https://link.theepochtimes.com/mkt_app/melatonin-affects-thrombosis-sepsis-and-covid-mortality-rate_4105459.html?utm_source=appan2028290