Tirzepatide may change how the body uses energy, trial suggests
· Medical Xpressedited by Sadie Harley, reviewed by Andrew Zinin
Sadie Harley
Scientific Editor
Meet our editorial team
Behind our editorial process
Andrew Zinin
Lead Editor
Meet our editorial team
Behind our editorial process Editors' notes
This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:
fact-checked
trusted source
proofread
The GIST Add as preferred source
Tirzepatide doesn't just help people lose weight; it also activates brown adipose tissue, representing a major milestone in obesity research, according to a study presented at ENDO 2026, the Endocrine Society's annual meeting in Chicago.
Until now, tirzepatide's weight-loss effect has been attributed primarily to reduced appetite, leading to smaller portions.
"In the TABFAT trial, we asked a different question: Beyond eating less, does tirzepatide also change how the body burns energy—specifically through brown adipose tissue, a metabolically active type of fat that produces heat and consumes calories?" said Rok Herman, M.D., from the Department of Endocrinology, Diabetes and Metabolic Diseases at University Medical Center Ljubljana in Ljubljana, Slovenia.
Brown adipose tissue was long thought to disappear after infancy and was only confirmed in adult humans through imaging studies in the late 2000s. It is markedly suppressed in obesity, and until now, moderate cold exposure has been its strongest known activator.
In a randomized, placebo-controlled clinical trial in premenopausal women with obesity, Herman and colleagues used cold-stimulated PET/CT imaging and MRI scans to measure brown adipose tissue activity before and after 24 weeks of treatment.
"We found that tirzepatide significantly increased brown adipose tissue activity and volume, and it also showed potential signs of converting white subcutaneous fat into more metabolically active 'beige' fat," Herman said.
Tirzepatide increased PET/CT-detectable brown adipose tissue activity from 41.2% to 64.7% of participants, while no comparable change was seen in the placebo group. "We were also encouraged by the consistency of the signal across other imaging modalities employed in the study that may capture different components of brown fat biology," Herman added.
"This adds a new layer to how we understand the new generation of anti-obesity medications," Herman said. "They are not only appetite suppressants—tirzepatide also appears to modulate energy expenditure at the tissue level, opening a plausible path toward future therapies that combine appetite regulation with thermogenic activation."
Herman suggests that future research measure, study and potentially enhance the use of brown and beige fat activity as a specific target for a tailored approach to obesity care.
Key medical concepts
Adipose Tissue, BrownTirzepatideObesity
Clinical categories
EndocrinologyWeight managementClinical pharmacology Provided by The Endocrine Society Who's behind this story?
Sadie Harley
BSc Life Sciences & Ecology. Microbiology lab background with pharmaceutical news experience in oil, gas, and renewable industries. Full profile →
Andrew Zinin
Master's in physics with research experience. Long-time science news enthusiast. Plays key role in Science X's editorial success. Full profile →
Citation: Tirzepatide may change how the body uses energy, trial suggests (2026, June 15) retrieved 15 June 2026 from https://medicalxpress.com/news/2026-06-tirzepatide-body-energy-trial.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.