Metformin: Scientists say drug prescribed to millions worldwide can mirror exercise without doing it

Scientists believe a common drug, already prescribed to millions around the world, could also provide the benefits of exercise sessions without actually exercising.

A new study from the University of Miami Miller School of Medicine‘s Sylvester Comprehensive Cancer Centre in the US discovered that the drug, metformin, likely mirrors the biological effects of exercise for people who are unable to do intense workouts.

The widely used diabetes medicine may trigger weight-regulating compounds released by the body during exercise in people who are inactive, the study found.

Australia has over 1.5 million diagnosed diabetes sufferers, with metformin one of the most common and often one of the first medications prescribed for Type 2 diabetes.

Metformin works in the body by reducing both basal (long-acting) and postprandial (after meals) plasma glucose and does not stimulate insulin secretion. In muscle it increases insulin sensitivity, improving glucose uptake into the muscle for use according to Diabetes Australia.

Metformin is usually prescribed for diabetes when diet and exercise are not enough to control blood sugar levels, but the study points to benefits for people suffering from other afflictions.

Men with prostate cancer, who can’t work out due to treatment, were able to take metformin and raise levels of a molecule tied to calorie burning and weight loss.

“From a clinical standpoint, seeing a metabolic signal that mirrors what we associate with intense exercise was striking,” said oncologist Dr Marijo Bilusic via The Sun.

“For patients whose treatments or symptoms limit physical activity, that kind of effect could be especially meaningful.”

Regular exercise is always encouraged during cancer treatment, but if that is not possible due to fatigue or illness, metformin may be the drug that can enable the release of specific biological signals in body.

Dr Bilusic said the study offers “a clearer understanding of how a widely used drug may support metabolic health during prostate cancer treatment — an outcome that matters to patients and clinicians alike.”

A molecule called N-lactoyl-phenylalanine, or Lac-Phe, which spikes in the body after an intense workout and coincides with exercise-derived benefits such as appetite regulation and calorie burning.

Previous research has in fact linked Lac-Phe to weight loss and a reduction in appetite.

Scientists have also observed higher Lac-Phe‑ levels in people taking metformin, even if they’re not working out.

The Sylvester study focused on people with prostate cancer, who often struggled with weight gain, poorer control of blood sugar and increased risk of heart disease due to hormone therapy.

Hormone therapy reduces or blocks testosterone production, as the hormone can fuel cancer growth.

Researchers took blood samples from 29 people and found patients taking metformin had similar levels of Lac-Phe to those seen in people doing strenuous exercise.

This occurred even though patients were not exercising at the time their blood was tested, and the effect persisted after they began hormone therapy.

Researchers said Lac-Phe appears to reflect how the body manages weight, calories and blood sugar during treatment.

Patients taking metformin while receiving other cancer treatments also saw elevated levels of Lac-Phe.

“What’s encouraging about this work is that it reminds us cancer care isn’t only about targeting tumours – it’s also about supporting the whole patient,” said Priyamvada Rai, a professor of radiation oncology at the Miller School.

“By better understanding how treatments affect metabolism, we can begin to identify ways to help patients maintain strength, resilience and quality of life throughout their care.”