No evidence that melatonin can be a treatment for COVID-19

With more than 11 million cases of COVID-19 in the United States and few treatments available, it’s no wonder that a study suggesting melatonin may treat — or even prevent — the coronavirus has gained attention. But alluring as it is to think that a sleep aid sold at most drugstores can cure this virus, experts tell Yahoo Life that those believing it’s a silver bullet are significantly off the mark.

“It’s a gigantic leap,” says Dr. Ryan Marino, an emergency room physician and medical toxicologist in Ohio. “This finding may certainly be worth studying further, but it will not change how I treat my patients or myself, and I would urge everyone caution in interpreting these headlines.”

The study was published in the journal PLOS Biology this week, accompanied by a press release from the Cleveland Clinic, where it was conducted, that said that researchers had used data to “identify melatonin as a possible treatment for COVID-19.” The study’s authors utilized electronic records to analyze the link between the two, concluding that “melatonin usage was associated with a nearly 30 percent reduced likelihood of testing positive for SARS-CoV-2 after adjusting for age, race, smoking history and various disease comorbidities.”

A study from the Cleveland Clinic drawing an association between melatonin use and reduced rates of COVID-19 is drawing criticism from experts. (Getty Images)
A study from the Cleveland Clinic drawing an association between melatonin use and reduced rates of COVID-19 is prompting criticism from experts. (Getty Images)

Marino describes the press release as “irresponsible and factually unsupportable” and says that while it is an “interesting finding,” it’s one that may be giving people false hope.

Melatonin is defined by the National Institutes of Health as “a hormone that your brain produces in response to darkness.” Classified as a dietary supplement by the Food & Drug Administration, it is one of the most widely used sleep aids in the U.S. While it is not regulated like a drug, many doctors have come to embrace melatonin, with the Mayo Clinic describing it as “safe for short-term use,” saying there is evidence showing that it “provides some insomnia relief.”

When used under doctor’s supervision, the supplement can be useful for alleviating sleep issues. But as a treatment for COVID-19, Marino says, it’s not a good idea. He elaborates on what he calls “major problems” within the study. “One, the finding is an association only and, given the lack of any plausible mechanism, should not be mistaken for true cause and effect,” says Marino. “While I would not dismiss it outright, it would certainly be much easier to explain this through unidentified confounding factors — for example, people who take melatonin are more likely to practice other interventions to try to protect their health.”

There are many reasons those taking melatonin may be experiencing COVID-19 in lower numbers, including improved sleep, better overall health and a more significant commitment to safety precautions.

On top of that, he suggests that only a randomized trial would be able to establish a causal connection. “Observational studies like this are usually not able to show us whether anything truly prevents or treats a condition but just can identify correlations that then can be further studied,” says Marino. The study’s lead author, Feixiong Cheng, assistant staff in the Genomic Medicine Institute, seems to agree. In the press release on Cleveland Clinic’s site, Cheng advised against running out to buy the supplement.

“It is very important to note these findings do not suggest people should start to take melatonin without consulting their physician,” said Cheng. “Large-scale observational studies and randomized controlled trials are critical to validate the clinical benefit of melatonin for patients with COVID-19, but we are excited about the associations put forth in this study and the opportunity to further explore them.”

The Cleveland Clinic, in response to a request for comment, noted that the study was peer-reviewed and that the headline of the press release “reflects the paper’s findings,” adding “the summary on Lerner’s web site emphasizes that this is a potential drug candidate for COVID-19 and further research is needed to validate theses initial findings.”

After Marino tweeted about the study, other doctors expressed similar fears about the way it has been framed. “It is simultaneously not at all surprising and incredibly disappointing that @ClevelandClinic is peddling bulls*** like this, and in so doing further eroding societal scientific literacy by spurring on predatory, clinical-evidence-not-required bandwagon fueling supplement sales,” tweeted Dr. Yoni Freedhoff, an associate professor of family medicine at the University of Ottawa.

Like other experts, Marino emphasizes that the Centers for Disease Control and Prevention’s guidelines for staying safe remain the most important. “As of right now there are no good treatment options for COVID-19, and the best way to prevent it is to practice distancing, masking and good hand hygiene,” says Marino. “A sure way to prevent disease spread is to avoid gathering in groups this Thanksgiving, as we are currently seeing uncontrolled virus spread in every part of the country.”

For the latest coronavirus news and updates, follow along at According to experts, people over 60 and those who are immunocompromised continue to be the most at risk. If you have questions, please reference the CDC’s and WHO’s resource guides.