Share on PinterestResearchers discuss why a common diabetes drug may help prevent long COVID. Image credit: Comezora/Getty Images
- More than one third of people who have had COVID-19 develop long COVID.
- There is currently no cure for long COVID, and receiving the COVID vaccine is considered the best way to gain protection against this condition.
- A new research commentary suggests that taking a common diabetes drug during or soon after infection with the SARS-CoV-2 virus that causes COVID-19 may help prevent long COVID.
Researchers estimate that more than one third of people who have had COVID-19 go on to develop long COVID, a chronic continuation of the disease that occurs for at least 3 months.
Some common symptoms of long COVID include extreme tiredness, brain fog, respiratory problems, heart palpitations, and joint and muscle pain.
Previous research shows that long COVID can lead to several serious health complications, including postural orthostatic tachycardia syndrome (POTS), stroke, fibromyalgia, anxiety disorder, chronic fatigue syndrome, and chronic kidney disease.
There is currently no cure for long COVID. The condition is normally treated with several therapies, including medications to manage symptoms, mental health support, and different types of therapies, such as physical or respiratory therapies.
Because anyone can develop long COVID, receiving the COVID vaccine, which helps prevent COVID-19, is considered the best means of protection against the chronic condition.
Now, a new commentary published in the journal Clinical Infectious Diseases suggests that taking a common diabetes drug — metformin — during or soon after infection with SARS-CoV-2 virus that causes COVID may help prevent long COVID.
Why focus on metformin and long COVID
In their commentary, researchers utilized data from multiple randomized clinical trials and electronic health record studies to examine how the diabetes medication metformin might impact long COVID risk.
“Long COVID has negative impacts on the health of many individuals every year,” Carolyn Bramante, MD, MPH, assistant professor of medicine in the Division of General Internal Medicine at the University of Minnesota, and co-author of this study, told Medical News Today.
“Many studies pre- and post-2020 show how metformin’s mechanisms of action reduce viral load of other viruses and are relevant to SARS-CoV-2,” added Bramante.
“As an obesity medicine physician, I was aware of metformin’s good tolerability, low cost, and safety (including in pregnant individuals), so it made sense to study in a [randomized clinical trial],” she told us.
What is metformin?
Metformin is commonly used to treat type 2 diabetes. Researchers estimate more than 120 million people with type 2 diabetes around the world use metformin.
Metformin is also sometimes prescribed for other types of diabetes, including prediabetes and gestational diabetes, which occurs during pregnancy.
Metformin is also sometimes prescribed off-label to treat a variety of medical issues, including polycystic ovary syndrome (PCOS), obesity, and weight gain caused by antipsychotic medications.
Researchers have also been examining the off-label treatment of other health conditions with metformin, including Alzheimer’s disease, nonalcoholic fatty liver disease (NAFLD), gum disease, kidney fibrosis, cardiovascular disease, and cancer.
Metformin after SARS-CoV-2 infection tied to lower long COVID risk
The commentary notes that participants who took metformin during or shortly after becoming infected with the SARS-CoV-2 virus significantly lowered their risk of developing long COVID.
On average, one case of long COVID was prevented for every 50 cases of acute SARS-CoV-2 treated with 14 days of metformin.
“This body of evidence means that starting metformin at the time of infection can reduce the risk of long COVID for most adults who get COVID-19 today,” Bramante detailed.
“This rough average of one case prevented for every 50 cases treated indicates that fewer individuals are being diagnosed with Long COVID now as compared to earlier in the pandemic. But using a $1 intervention has big public health implications,” she emphasized.
How metformin helps reduce viral load
Additionally, the commentary notes that metformin significantly decreased SARS-CoV-2 viral load and helped prevent rebound of viral load, when compared to placebo.
“It is important for understanding that metformin’s actions on the immune system help the body to lower the amount of virus, even though metformin does not act directly on the virus itself, like an antiviral medication might,” Bramante explained.
The commentary also reported that taking metformin during COVID-19 did not cause any low blood sugar or serious side effects, and that based on their findings, metformin could be used either alone or with other treatments for the SARS-CoV-2 virus.
Bramante explained how metformin might help potentially lower a person’s long COVID risk:
“Metformin is known to activate AMPK (AMP-activated protein kinase) in a way that is anti-inflammatory and protects metabolic function. Metformin also benefits the gut microbiome and the leakiness of the gut — studies have found that SARS-CoV-2 harms the gut microbiome and makes the gut leakier.”
Another potential benefit of metformin
MNT also had the opportunity to speak with Fady Youssef, MD, a board-certified pulmonologist, internist and critical care specialist at MemorialCare Long Beach Medical Center in Long Beach, CA, about this study.
Youssef, who was not involved in this research, commented that metformin is a well-known, widely used medication, and seeing evidence that it may reduce the risk of long COVID when used early is encouraging.
“While this doesn’t change practice overnight, it adds to a growing body of research suggesting there may be ways to lower long-term risk after acute infection and adds another potential benefit to metformin,” he explained.
“Long COVID is complex and still poorly understood. The lack of clear diagnostic tests reflects gaps in our understanding of the underlying biology, which is why prevention research using safe, accessible medications is so important,” Youssef told us.
According to the pulmonologist: “The next step is understanding [the] mechanism — whether metformin affects viral persistence, immune dysregulation, inflammation, or metabolic health, and what that reveals about the core biology driving long COVID.”
“Clarifying these pathways is what will move us toward targeted diagnostics and effective prevention,” he added.
