May 12, 2023 -- Metformin, a drug commonly used to treat type 2 diabetes, greatly decreases a person’s risk of developing long COVID after infection, according to a study published in The Lancet.
Study participants who took metformin were more than 40% less likely to develop long COVID than those who received a placebo, researchers found. Study participants who started taking metformin less than four days after their COVID symptoms started cut their risk of long COVID by 63%.
“The results of this study are important because long COVID can have a significant impact on people's lives,” Carolyn Bramante, MD, principal investigator and an assistant professor at the University of Minnesota Medical School, said in a news release. “Metformin is an inexpensive, safe and widely available drug, and its use as a preventive measure could have significant public health implications.”
More than 1,200 randomly chosen people at six U.S. sites participated in the study. They were given metformin or a placebo, with an additional subset of participants receiving ivermectin, fluvoxamine, or their placebos. Participants were between 30 and 85 years old who qualified as overweight or obese. Half had been vaccinated and none had previously been infected with COVID.
Ivermectin and fluvoxamine didn’t make any difference in people getting long COVID, the study found.
Metformin is sold under the brand names Fortamet, Glucophage, Glumetza, and Riomet.
A simulator developed by University of Minnesota Medical School and College of Science and Engineering’s Biomedical Engineering faculty predicted the effectiveness of metformin, the university said in the news release. The simulator earlier successfully predicted the failure of hydroxychloroquine and the success of remdesivir before the results of clinical trials on those drugs were announced.
The study team said more research is needed to determine whether metformin works for people with previous COVID infections or those with lower body mass index.
People with long COVID often have symptoms weeks or months after infection. The most common long COVID symptoms were deep fatigue, a hard time concentrating, muscle aches, and shortness of breath.