A recent UK study has made global headlines by showing that metformin, one of the world's most widely prescribed diabetes medications, could cut the risk of Long COVID by 64% in overweight or obese adults who started the drug within 90 days of infection. The large observational study, published in Clinical Infectious Diseases, analysed health records of over 624,000 UK adults with COVID-19 between March 2020 and July 2023. Among these, nearly 3,000 patients who began metformin treatment soon after diagnosis were tracked for a year. Compared to non-users, their likelihood of developing Long COVID, defined as persistent symptoms 90 days or more after infection, was dramatically lower.
This adds weight to findings from the COVID-OUT randomised trial in the US, which showed a 63% risk reduction in Long COVID with a 14-day course of metformin given early in infection. Together, these results spotlight metformin as a surprisingly powerful, low-cost tool against one of COVID-19's most puzzling legacies.
But the story is particularly significant for India, where metformin is not just a diabetes drug but also a frontline therapy for PCOS (polycystic ovary syndrome) and is sometimes prescribed off-label in managing Long COVID symptoms. With over 100 million people living with diabetes in India (as per ICMR, 2023), and PCOS affecting nearly one in five Indian women of reproductive age, this new evidence could have far-reaching implications.
Metformin: India's Most Prescribed Diabetes Drug?
Metformin has been the first-line treatment for type 2 diabetes in India for decades. Its benefits include:
- Lowering blood glucose by reducing liver glucose production.
- Improving insulin sensitivity.
- Offering cardiovascular protection.
ICMR guidelines continue to recommend metformin as the initial therapy for most adults with type 2 diabetes, given its affordability, effectiveness, and relatively mild side-effect profile.
PCOS Management
In India, metformin is also routinely prescribed for PCOS, a condition marked by irregular periods, insulin resistance, and infertility risk. Studies from AIIMS and international reviews confirm its role in improving ovulation and reducing insulin resistance in women with PCOS. This dual use means millions of Indian women and men are already taking metformin daily, long before COVID-19 emerged.
Now, The Long COVID Connection
With up to 10-30% of COVID-19 survivors reporting lingering symptoms such as fatigue, brain fog, and breathlessness, Long COVID represents a significant burden in India too. The new UK study suggests that metformin could help prevent these complications, potentially offering relief to millions if findings hold true locally.
Cautions And Considerations For India
Despite all of these findings and the common use of metformin in India for a number of health issues, especially diabetes, PCOS and Long COVID, one should be cautious about consuming the medication and do so under the guidance of a reliable doctor. This is because, like all drugs, metformin has side effects and risks involved. Here are all the reasons why consuming metformin only when prescribed by a doctor is vital for all Indians:
Not A Magic Bullet
Doctors warn against self-prescribing metformin solely to prevent Long COVID. The UK study participants were overweight or obese adults, a group where insulin resistance is common. We don't yet know if the protective effect extends to leaner populations, common in India's rural heartlands.
Safety Concerns
Metformin is generally safe but requires medical supervision:
- Kidney disease patients must be cautious due to rare risk of lactic acidosis.
- Long-term use may lower vitamin B12 levels, requiring monitoring.
- Side effects like gastrointestinal discomfort (nausea, diarrhoea) are common early on but usually resolve.
Policy Implications
If confirmed by Indian studies, metformin could be an accessible, low-cost preventive strategy for high-risk COVID patients. But premature widespread use could cause over-prescription, strain on supply, or misuse by those without medical need.
What Indian Patients Should Do
Diabetes patients should continue metformin as prescribed. You may already be gaining protective benefits against Long COVID. For women with PCOS, if on metformin, continue under your gynaecologist's guidance, because there's no reason to stop unless your doctor says so. But for Long COVID patients and the general public, exercising caution is vital. Do not start metformin without consulting a doctor. Its benefits appear strongest if started early in overweight/obese individuals as per the new study.
Disclaimer: This content including advice provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.
References:
Chaichana U, et al. Effect of Metformin on the Risk of Post-coronavirus Disease. Clin Infect Dis. 2025.
Bramante CT, et al. COVID-OUT Randomized Trial: Metformin & Long COVID Prevention. Lancet Infect Dis. 2023.
NIH News Release: Metformin use in adults with diabetes linked to lower risk of Long COVID. 2024.
Indian Council of Medical Research. India Diabetes Study, 2023.
Zeng W, et al. Metformin in polycystic ovary syndrome: unraveling multi-stage therapeutic mechanisms from puberty to long-term health outcomes. Frontiers In Oncology, 2025.
World Health Organization. Long COVID factsheet.
