Blood Pressure Drug Losartan Found to Activate Brown Fat in Study of 100,000 Patients
Researchers at Rockefeller University analyzed PET/CT imaging and clinical records from more than 100,000 patients and found that losartan, a common blood pressure medication, activates brown fat. Brown fat burns energy rather than storing it, and higher brown fat activity was linked to lower rates of cardiovascular disease, metabolic conditions, and even anxiety and depression. The findings were published in Nature on October 14, 2026.
A study published in Nature on October 14, 2026, found that losartan, a widely prescribed blood pressure medication, can activate brown adipose tissue, commonly known as brown fat. The research was led by scientists at Rockefeller University and funded in part by the National Institutes of Health.
Unlike white fat, which stores energy, brown fat burns energy to generate heat. Higher levels of brown fat activity have been associated with better metabolic health, and researchers have long sought ways to stimulate it therapeutically.
The team used artificial intelligence to analyze PET/CT imaging and clinical records from more than 100,000 patients who had been treated for cancer. Patients taking angiotensin receptor blockers, the drug class that includes losartan, showed higher levels of brown fat activity than those who were not.
The study also found that individuals with greater brown fat activity had lower rates of cardiovascular and metabolic diseases. A novel finding was a link between brown fat activity and reduced rates of anxiety and depression. Among the body's six brown fat depots, activity in the armpit region showed the strongest association with cardiometabolic health.
Follow-up experiments in mice confirmed that losartan directly increased the metabolic activity of brown fat cells. Crucially, this effect operates through molecular pathways separate from those responsible for lowering blood pressure. That distinction matters because it suggests future therapies could potentially stimulate brown fat without affecting blood pressure in patients who do not need it.
Researchers emphasized that human clinical trials are needed before any conclusions can be drawn about using losartan specifically to activate brown fat. Experts advise patients not to take the drug for this purpose without medical guidance.
