New research suggests losartan, a widely prescribed blood-pressure medication, may help the body burn more energy. But scientists have not shown that it causes weight loss or provides new health benefits in people.
If you take medication for high blood pressure, the name losartan may sound familiar.
Now scientists are studying whether that same medicine could do something unexpected: activate a type of body fat that burns energy.
It’s an interesting discovery. But there’s an important detail behind the headlines.
The drug increased brown-fat activity in laboratory experiments and mice. Researchers have not proved it has the same effect in people.
The findings, published October 14 in the scientific journal Nature, could help scientists better understand how the body uses energy and regulates metabolism.
What is brown fat, and why are scientists interested?
Most of the fat in our bodies stores energy. Scientists call it white fat.
Brown fat does something different. It burns energy to produce heat, helping keep the body warm.
Adults have brown fat, too, although some people have more active brown fat than others.
Scientists want to understand whether increasing its activity could eventually help with conditions such as diabetes or heart disease.
But there’s a difference between helping the body burn energy and proving that a treatment helps people lose weight or stay healthier.
The new study hasn’t answered that question.
Researchers examined medical records and specialized scans from more than 100,000 patients at a cancer center.
The scans, originally taken for cancer care, also allowed scientists to identify brown fat.
People with detectable brown fat were less likely to have certain health conditions, including some cardiovascular problems, anxiety and depression.
Researchers also found connections between greater brown-fat activity and better measures of metabolic health, including how the body processes energy.
But these findings don’t prove that brown fat prevented those conditions.
The researchers were looking at existing patient records, not testing whether increasing brown fat would improve someone’s health.
And because the patients were receiving care at a cancer center, the results may not represent the broader population.
Why a blood-pressure medication caught their attention
The researchers noticed something else in the medical records.
Patients taking a group of blood-pressure medicines called angiotensin receptor blockers, or ARBs, were more likely to have detectable brown fat.
Losartan belongs to that group.
Scientists then tested losartan in brown-fat cells and in mice.
According to the National Institutes of Health, the medication increased signs of brown-fat activity and energy use in those experiments.
But here’s an important finding: The mice did not experience a significant change in body weight.
In other words, burning more energy did not automatically translate into weight loss.
Researchers also found clues suggesting that losartan may affect brown fat through a process separate from how it lowers blood pressure.
That could give scientists another path to investigate. It doesn’t mean doctors have discovered a new use for the medication.
Why this research is important for Latino families
High blood pressure is a familiar health concern in many Latino households.
According to the U.S. Department of Health and Human Services, about 42% of Hispanic and Latino adults had high blood pressure during 2021–2023.
The challenge isn’t only identifying high blood pressure. It’s also keeping it under control.
We also reviewed a 12-year study of Hispanic and Latino adults that found many participants developed high blood pressure over time, while relatively few achieved recommended blood-pressure levels.
The consequences are important. Uncontrolled high blood pressure increases the risk of heart disease, stroke and kidney problems.
Our earlier reporting on cardiovascular disease among California Latinos also examined the impact in Los Angeles.
That’s why new research involving a familiar blood-pressure medicine deserves attention.
But the brown-fat study did not show that losartan provides additional benefits for Latino patients or that activating brown fat would improve their health.
Those questions remain unanswered.
Could losartan become a weight-loss treatment?
Not based on what scientists know today.
The study did not include a human clinical trial showing that losartan activates brown fat or helps people lose weight.
Researchers would need to test the medication in people, measure whether brown-fat activity changes and determine whether those changes lead to meaningful health benefits.
They would also need to examine safety and possible side effects.
A medicine that works one way in mice may not produce the same results in humans.
For now, losartan remains a blood-pressure medication, not an established treatment for weight loss or metabolic disease.
What should patients taking losartan do?
Keep following your prescribed treatment.
This research is not a reason to start losartan, take more of it or stop using it.
If you take the medication and have questions about your blood pressure, weight or other health conditions, speak with your doctor or pharmacist.
Parriva’s guide to blood-pressure medication recalls also explains why patients should check with a healthcare professional before changing prescribed treatment.
The new discovery gives researchers something valuable to investigate.
For patients, the distinction is simpler: Scientists have found a possible connection between a familiar medicine and how the body burns energy.
Whether that discovery can actually help people live healthier lives is something future research still needs to prove.
