SAN DIEGO (KGTV) — Multiple studies have found the sleep aid melatonin helps patients with severe COVID-19 recover. Now, early data on animals offers a glimmer of hope that it might benefit long haulers experiencing neurological symptoms as well.
Melatonin is a hormone produced by the body. It is most famous for its impact on the circadian rhythm, but doctors have long known it also has antioxidant and anti-inflammatory properties.
Since out-of-control inflammation is one of the hallmarks of severe COVID-19, scientists set their sights on melatonin supplements as a potential therapy early in the pandemic.
In October, a clinical trial involving 150 hospitalized COVID patients in Iraq found those taking 10 mg of melatonin each night before bed had a lower risk of COVID-related blood clots, sepsis, and death. Just one hospitalized patient taking melatonin died compared to 13 deaths in the control group.
A retrospective study in Spain found hospitalized COVID patients who received melatonin early in the pandemic had a nearly 40% lower risk of death. A randomized, controlled trial on about 100 hospitalized COVID patients in Iran found it improved sleep quality and blood oxygen levels but was inconclusive on survival rates.
This week, researchers in France released data showing that high doses of melatonin blocked the coronavirus from entering the brains of mice. Melatonin also reduced swelling there. The paper has not yet been peer-reviewed.
The findings may have implications for the millions of sufferers of long COVID, the authors said.
“Unfortunately, we don’t have any treatments for long COVID syndrome itself. What we do have are symptomatic therapies,” said Dr. Navaz Karnjia, a neurologist at UC San Diego who was not involved with the study.
About 55% of COVID patients have at least one lingering symptom for at least six months after their infection, she said. Those symptoms include fatigue, headaches, and difficulty concentrating or “brain fog.”
Scientists think these neurological issues happen when the coronavirus enters brain cells via a receptor called ACE-2. The French study found melatonin changed the shape of the ACE-2 receptors, preventing the virus from getting in.
It’s encouraging but far from conclusive, Dr. Karnajia said. Based on the weight of the mice, the researchers were administering the equivalent of 3,500 mg of melatonin, she said.
“Most of us, if we’re taking melatonin for sleep, are taking 3 mg of melatonin, not 3,500. So they’re taking over 1,000 times the dose,” she pointed out.
Still, there are at least a half-dozen clinical trials on melatonin and COVID underway.
Some researchers are exploring whether melatonin can be used to treat mild COVID symptoms early on, or even prevent infections.
A study early in the pandemic by the Cleveland Clinic found people taking melatonin had a 28% lower chance of getting infected with COVID in the first place.
Last year, doctors in Texas published a paper arguing that newly infected COVID patients should start taking melatonin daily, as early as the first night they test positive.
“Our recommendation is to administer melatonin 2.5 to 10 mg at night to all adults diagnosed with SARS-CoV-2 as early as on the first day of diagnosis, especially for those at increased risk for morbidity or mortality,” they wrote.
Although experimental data suggests melatonin might fight early viral replication, they urged people not to misunderstand melatonin’s role.
“The use of melatonin in patients with COVID-19 is not meant to be used as a cure but instead as an agent that equips the body to better fight viral infection,” they wrote.