Overview
- Researchers presented the randomized, placebo-controlled TABFAT trial at ENDO 2026 showing tirzepatide increased brown adipose tissue (BAT) activity and volume after 24 weeks in 34 premenopausal women.
- Cold-stimulated FDG-PET/CT detection of BAT rose from 41.2% at baseline to 64.7% at 24 weeks in the tirzepatide group with no comparable change in placebo.
- The tirzepatide group lost a median of 13.5% of body weight and investigators reported that the BAT activation signal did not correlate with the degree of weight loss.
- BAT changes were consistent across three imaging methods—cold-stimulated FDG-PET/CT, thermoneutral MRI fat‑fraction measures, and cold-stimulated infrared thermography—strengthening a mechanistic signal but not proving clinical benefit.
- The study is small and hypothesis-generating, investigators are analyzing adipose biopsies and RNA sequencing now, and they say larger, more diverse trials are needed to determine whether BAT activation meaningfully changes obesity treatment or weight maintenance.