Metformin is an active ingredient that many see as a kind of miracle cure. It helps people with type 2 diabetes to regulate their sugar levels and prevents them from complications such as strokes and heart attacks. In the case of overweight people, the drug has recently also been used as a weight loss aid because it can suppress the feeling of hunger. And off-label — without direct approval for that diagnosis — it’s recommended for many overweight women to treat polycystic ovary syndrome. Metformin is also easy to take as a pill and comparatively cheap. In short: It is a drug that can help many patients.
Now, things seem to be getting even better: metformin could alleviate one of the biggest health crises of the era. In a preprint published in the British medical journal The Lancet, it shows amazing success in preventing Long Covid.
In the study, led by Carolyn Bramante of the University of Minnesota, 1,323 randomly selected patients who had SARS-CoV-2 infection were treated with one of the active ingredients metformin, ivermectin, fluvoxamine or a placebo. The study was blinded and conducted at various centers in the United States. The patients were between 30 and 85 years old and all had an increased risk of a severe course of Covid 19 and long Covid due to their overweight.
A little more than half of the subjects were fully vaccinated, a small proportion had already received a booster vaccination. 95 percent of the participants were examined monthly for more than nine months to determine whether and which long-Covid symptoms they had.
Risk reduced by more than 40 percent
Overall, 8.4 percent of participants were diagnosed with Long Covid, slightly less than the 12 percent average found in one of the most comprehensive cohort studies on the subject. In fact, 10.6 percent of the placebo group developed Long Covid in the study. In the metformin-treated group, it was only 6.3 percent. These data hardly varied between different subgroups of patients, i.e. young versus old participants, and also not between different virus variants.
Metformin worked well when people took one tablet (500 milligrams) for four days after infection, then two tablets a day for four days, and then three tablets for three more days.
With the other active ingredients, ivermectin (a drug used to treat parasites in animals or scabies in humans) and fluvoxamine (a serotonin reuptake inhibitor used to treat depression), the scientists found no difference to the placebo can. They did not prevent Long Covid from occurring.
The American molecular biologist Eric Topol, founder and director of the Scripps Research Translational Institute, shared the preprint on Twitter with the conclusion “This is good news”. The treatment would cost less than a US dollar in total.
The effect has so far only been researched in overweight people
Why metformin protects against Long Covid has not yet been finally clarified. It is also known from diabetes research about its mechanism of action that it inhibits the formation of glucose in the liver. It also inhibits the absorption of glucose from the intestine. Both are desirable in diabetics because their blood sugar levels rise less sharply after eating on metformin. In addition to this effect, an antiviral and anti-inflammatory effect is also being discussed for metformin, both of which could explain the protection against Long Covid. In laboratory tests, it seems to prevent the aging process of nerve cells that can be triggered by SARS-CoV-2. Previous studies have shown that the early administration of metformin can reduce the viral load in the patient’s blood and thus reduce the risk of severe courses. After all, since metformin has been widely researched and approved for the treatment of type 2 diabetes, it can already be said that it has hardly any side effects. This fuels hope for a good and cheap remedy for Long Covid.
The study authors point out that the definition of Long Covid has changed over the course of the investigation. So that could have led to over- or under-diagnosis of Long Covid in the different subgroups. In addition, all participants were people who had a significantly increased risk of long Covid due to their overweight. According to the scientists, this study cannot provide any information about the effect of metformin on people of normal weight. In view of the reduction in risk by more than 40 percent, further research is urgently needed.