In the search for treatments to help people with severe COVID-19, researchers across the globe are trying to find new uses for existing medicines to prevent more coronavirus-related deaths.
The reservoir of options includes melatonin — a hormone naturally found in the body that regulates sleep cycles.
Studies have shown the hormone can help lower high blood pressure, reduce anxiety and generally improve quality of sleep, but a paper published in November suggests melatonin can reduce the likelihood of testing positive for SARS-CoV-2, the virus that causes COVID-19.
It was one of the medicines given to President Donald Trump during his bout with the disease.
After screening nearly 27,000 patients in a Cleveland Clinic Health System COVID-19 registry, a team found that the use of melatonin was associated with a 28% reduced probability of contracting coronavirus after adjusting for age, race, smoking history and several underlying health conditions.
Researchers don’t yet know the exact reason behind the positive correlation, but other research suggests it’s because of melatonin’s ability to regulate the immune system and reduce inflammation — the latter of which is known to cause several lasting symptoms post coronavirus infection such as brain fog, headaches and fatigue.
However, the findings only offer an association between the hormone and COVID-19 and do not prove cause and effect. Clinical trials are underway to test the connection.
If proven clinically beneficial, melatonin could be one of the cheapest and most readily available treatments for COVID-19. It’s already sitting on shelves in drugstores across the nation.
“It is very important to note these findings do not suggest people should start to take melatonin without consulting their physician,” study lead author Dr. Feixiong Cheng, a data analyst at the Cleveland Clinic’s Genomic Medicine Institute, said in a news release.
“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,” Cheng said.
The study also unveiled a 52% reduced likelihood of testing positive for coronavirus for Black patients following melatonin usage. Patients with diabetes also benefited from reduced risks of getting the virus, but no “significant” associations were found for patients with asthma or high blood pressure.
Scientists have reason to believe melatonin can improve coronavirus patient outcomes because of its ability to control how immune systems react to imbalances, such as infections.
Experts know that the coronavirus can trigger “a massive inflammatory reaction,” also known as a “cytokine storm,” in the body that can lead to permanent tissue damage, heart injury, acute respiratory distress syndrome (ARDS), organ failure and death, according to a study published in May in the journal Frontiers in Medicine.
It’s as if the body is unintentionally attacking itself, experts say.
Melatonin can control and reverse this innate immune response, suggesting it may have beneficial effects in preventing or reducing the inflammation overload, and thus lowering people’s chances of developing COVID-19 and dying.
In other words, the hormone may be able to increase someone’s ability to tolerate the virus if infected, Cheng told Healthline. In turn, this gives the immune system time to develop its own response, such as producing antibodies, to fight the virus.
Not to mention, melatonin can help improve sleep quality that keeps immune systems working properly to better fight and prevent infections.
A separate, nonpeer-reviewed study posted in October revealed that melatonin usage after intubation — when a tube is inserted down a patient’s throat to make room for a breathing ventilator — was associated with “a positive outcome” in hospitalized COVID-19 patients.
A group of international scientists at the University of Buffalo’s Jacobs School of Medicine and Biomedical Sciences in New York are set to begin a randomized, double-blind, placebo-controlled clinical trial — the golden standard for medical research — to test melatonin’s effect on COVID-19.
A total of 30 patients with mild COVID-19 are being enrolled, 20 of whom are being treated with melatonin and 10 with a placebo.
Researchers hope to learn if melatonin proves to help COVID-19 patient outcomes and which doses are effective and safe.
