Researchers Identify Melatonin as Possible COVID-19 Treatment

Woman pouring pills into hand.

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Key Takeaways

  • Melatonin is linked to a nearly 30% reduced likelihood of testing positive for SARS-CoV-2, the virus that causes COVID-19.
  • Researchers are hoping to find an already-approved drug they can “repurpose” to treat COVID-19.
  • The mechanism behind why melatonin may help is unclear.

It’s easy to forget that COVID-19 is still a relatively new virus. And, with that, scientists are still trying to discover ways to treat it. Now, a new study suggests that one potential treatment for the virus could be found at your local pharmacy: the common sleep aid melatonin.

The November study, which was published in the journal PLOS Biology, analyzed patient data from Cleveland Clinic's COVID-19 registry. The researchers discovered that melatonin usage was linked to a nearly 30% reduced likelihood of testing positive for SARS-CoV-2, the virus that causes COVID-19, after scientists adjusted for age, race, smoking history, and comorbidities. The numbers were even higher among people in certain groups: African-Americans had a 52% reduced likelihood of testing positive, while people with diabetes had a 48% lower risk.

The researchers then analyzed large-scale electronic health records from Cleveland Clinic patients to find similarities between COVID-19 and other diseases. They specifically measured the proximity between host genes and proteins, and those that are linked with 64 other diseases across several disease categories, including malignant cancer and autoimmune, cardiovascular, metabolic, neurological, and pulmonary diseases, to try to find similarities.

The researchers discovered that proteins linked with respiratory distress syndrome and sepsis, which are two main causes of death in patients with severe COVID-19, had connections with multiple SARS-CoV-2 proteins. This suggested that a drug that has already been developed to help treat those conditions may also help with COVID-19.

As a whole, the researchers found that autoimmune, pulmonary, and neurological diseases had the biggest proximity to SARS-CoV-2 genes and proteins. They flagged 34 drugs for possible “repurposing” use—which entails using them for a reason outside of their original intended use. Melatonin was the top contender. 

Study co-author Feixiong Cheng, PhD, assistant staff in the Cleveland Clinic’s Genomic Medicine Institute, tells Verywell that he and his colleagues decided to study this because “there are no FDA-approved effective medications for patients with early COVID-19.” And, he says, it can be a while until that happens. “Traditional de novo drug discovery is costly and we have to wait a long time—10 to 15 years,” he says.

That’s why the team is interested in “repurposing” a medication or supplement that’s already available to the general public. “Drug repurposing will significantly reduce cost and time for the emerging COVID-19 pandemic compared to traditional drug discovery approaches,” he says.

What This Means For You

Melatonin is a readily available over-the-counter supplement. If more research finds that it is effective against COVID-19, it could be an easily accessible treatment. Speak to your doctor before deciding to incorporate melatonin supplements into your routine.

What Is Melatonin?

Melatonin is a hormone that your body produces in response to darkness that also helps control your circadian rhythm (i.e. your sleep-wake cycle), according to the National Center for Complementary and Integrative Health (NCCIH).

Melatonin is also available as a dietary supplement and may help with the following issues, per the NCCIH:

  • Jet lag
  • Delayed sleep-wake phase disorder (DSWPD)
  • Some sleep disorders in children
  • Anxiety before and after surgery

While melatonin is often used for the treatment of sleep and anxiety issues, the NCCIH says that it may play other roles in the body. However, those roles are still being researched.

How Melatonin May Combat COVID-19

Melatonin may actually have a protective effect against SARS-CoV-2, specifically increasing the tolerance of the body to the virus, Cheng explains. 

By increasing the body’s tolerance, there may be a reduction in damage to tissue and organs “and allow the host to survive sufficiently long to develop an adaptive immune response,” Cheng says. As a result, your body may eventually be able to target and remove the virus from your body, he says.

Still, Cheng says, this isn’t definite. “There are many possible mechanisms of melatonin in treating COVID-19, and our group is actively investigating it using cell-based and pre-clinical models,” he says.

Jamie Alan, PhD, assistant professor of pharmacology and toxicology at Michigan State University who didn’t work on the study, tells Verywell that something entirely different could also be at play. “It's possible that people who use melatonin are the ones who are staying at home—and have a job and the means for childcare to stay home—and are masking up and social distancing,” she says. “There are many possible explanations.”

Overall, Cheng says, the effectiveness of melatonin in COVID-19 patients has to be determined by randomized controlled trials. “We hope we will receive some good news from ongoing trials, yet our large-scale patient data analysis and network medicine findings support the potential of possible treatment of melatonin in COVID-19 patients,” he says. “Importantly, the cost of melatonin is much lower than other drugs under ongoing COVID-19 trials, which will be great to fight the pandemic by accessibility to the general population.”

There are currently seven ongoing trials to test melatonin as a possible treatment for COVID-19, Cheng says.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Zhou Y, Hou Y, Shen J et al. A network medicine approach to investigation and population-based validation of disease manifestations and drug repurposing for COVID-19. PLoS Biol. 2020;18(11):e3000970. doi:10.1371/journal.pbio.3000970

  2. National Center for Complementary and Integrative Health. Melatonin: what you need to know.

By Korin Miller
Korin Miller is a health and lifestyle journalist who has been published in The Washington Post, Prevention, SELF, Women's Health, The Bump, and Yahoo, among other outlets.