Metformin Linked to Lower Long COVID Risk

A retrospective study of U.S. electronic health records found early metformin prescriptions were associated with fewer cases of long COVID or death.

Updated on Nov. 4, 2026 in COVID-19

Bold flat-color editorial illustration of smooth white tablets in a geometric arrangement on a cream field, with a single coral accent. — A University of Minnesota study found early metformin prescriptions linked to a 53% lower risk of long COVID or death within 180 days. AI Illustration. Upload story photo >

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If you caught COVID, would you ask a doctor about taking metformin to lower your risk?

Patients prescribed metformin within six days of SARS-CoV-2 infection had a 53% lower risk of developing long COVID or dying within 180 days, according to a study published October 29 in the Journal of Medical Virology. The research drew on deidentified electronic health record data from the National COVID Cohort Collaborative in the United States.

Why it matters

The findings add observational support to earlier randomized trials, including COVID-OUT and ACTIV-6, that evaluated metformin for preventing long COVID. The study's design emulated those trials, offering a comparison that may inform clinicians weighing treatment options for people recently infected with the virus.

The retrospective analysis compared 248 adults given metformin with 9,412 given fluticasone, fluvoxamine, ivermectin, or montelukast, finding 4.0% versus 8.5% developed long COVID or died after weighting. Whether the association reflects a true treatment effect has not been confirmed by a controlled trial in this population.

The players

Carolyn T. Bramante

Bramante is a researcher at the University of Minnesota Medical School who led the study.

The details

Researchers from the University of Minnesota Medical School, led by Carolyn T. Bramante, used entropy balancing to match the two groups on age, sex, race and ethnicity, BMI, prior medications, existing conditions and laboratory results. Patients with indications for metformin, including diabetes, were excluded from the analysis.

Days 0 to 6 after infection: window for the metformin or control prescription.
Within 180 days: follow-up period for the long COVID or death outcome.
October 29: study published online in the Journal of Medical Virology.

Health Landscape

The observational result is consistent with the COVID-OUT and ACTIV-6 randomized trials, which tested metformin against placebo for preventing long COVID. Together these studies are building a body of evidence on low-cost repurposed drugs for the post-infection condition.

For people recently diagnosed with COVID-19, the results suggest metformin may be worth discussing with a clinician, though the study does not establish it as a treatment. Patients with diabetes already prescribed metformin were not part of this analysis and should follow their existing care plans.

The takeaway

Early metformin use was associated with a substantially lower rate of long COVID or death in this large observational analysis. Anyone considering the drug for COVID-19 should consult a clinician, since observational data cannot confirm cause and effect.