Does Melatonin Offer Promise In Treating COVID?

By now you’ve all heard the news that the Moderna vaccine for COVID-19 has been 95 percent effective in early testing. Obviously this is nice to hear, and the only thing I have to add is that it’s good news for more than just its success against the coronavirus. Both Pfizer and Moderna employed an innovative mRNA technique to develop their vaccines, and the fact that they appear to be spectacular successes provides us with a ton of hope that this might usher in a whole new era of vaccine development. It’s too early to say anything for sure, but the prospects of a huge breakthrough in vaccine development are pretty exciting.
While we’re on the topic of COVID-19, however, a recent study provided another bit of good news. A team of researchers led by the Cleveland Clinic took a dive into a database of 26,779 individuals looking for possible associations between COVID-19 and other diseases and found something pretty interesting:
We found that melatonin was significantly associated with a 52% reduced likelihood of a positive laboratory test result for SARS-CoV-2 in black Americans after adjusting for age, sex, race, smoking, and various disease comorbidities.

A 52 percent reduction in positive tests is pretty spectacular. (White patients also benefited, but showed only a 23 percent reduction.) However . . .
WARNING: Every research result like this is tentative. It’s only one study, it might be biased, etc. In this case, though, the warnings need to be doubled or tripled. The researchers essentially just fed some data into a computer and looked for any two variables with significant correlations.¹ This is normally a big no-no and can’t be taken to prove much of anything. So take this result as very, very tentative.
So why did they do it? That’s easy: the purpose of a study like this is to identify things that deserve further study. By itself it might not provide strong evidence about melatonin, but it clearly identifies melatonin as something that should be the subject of a good RCT or other, more reliable, study designs:
Large-scale observational studies and randomized controlled trials are needed to validate the clinical benefit of melatonin for patients with COVID-19. It would be important, however, that the trials be designed with the understanding of the mechanism of the drug to be repurposed. For example, it would be obvious that drugs that decrease viral entry, e.g., part of melatonin’s action, would be beneficial in preventing infection or very early in the COVID-19 course, but may be inconsequential when utilized in severe or end-stage infection. Several randomized controlled trials are being performed to test the clinical benefits of melatonin in patients with COVID-19.
If the results eventually pan out, they’d provide us with two things. First, we’d have a cheap and easy way of reducing the risk of COVID-19. Second, it might provide a clue about why COVID is so devastating to Black patients.
And in the meantime, melatonin is cheap and harmless. Nobody should start taking without talking to a doctor. And don’t go nuts and assume that if you’re taking it you don’t have to wear a mask or socially distance yourself anymore.
¹There was a little more to it than that, but you get the idea.