A hormone already known for reducing appetite and supporting weight loss appears to have a second, independent job: protecting the liver from inflammation and scarring. The finding, published in the journal Cell Metabolism on August 10, 2026, could open new treatment paths for millions of people with advanced fatty liver disease.
Researchers at McMaster University discovered that the hormone GDF15 activates a previously unknown signaling pathway that runs from the brain through the nervous system to the liver. That pathway triggers the release of glucocorticoids, steroid hormones that play a role in metabolism, immune activity, and the body's response to stress. The glucocorticoids then help suppress inflammation inside the liver.
The study found that GDF15 can reduce liver inflammation and slow the development of liver scarring even when weight loss does not occur. That result challenges the long-held assumption that the hormone's benefits are tied primarily to its effects on appetite and body weight, according to Science Daily.
The disease at the center of the research is metabolic dysfunction-associated steatohepatitis, known as MASH. It is an advanced form of fatty liver disease that can lead to cirrhosis, liver cancer, and liver failure. Millions of people worldwide are affected by the condition. New weight-loss medications have improved outcomes for many patients, but inflammation in the liver can persist even after substantial weight loss, leaving a significant treatment gap.
To study how GDF15 affects advanced liver disease, the McMaster team used mouse models designed to closely reproduce human MASH. They combined genetic, pharmacological, genomic, and spatial transcriptomics techniques to trace what happens when the hormone becomes active in the body.
Gregory Steinberg, professor in McMaster University's Department of Medicine, co-director of the Centre for Metabolism, Obesity and Diabetes Research, and senior author of the study, described the significance of the pathway. "Our findings show that GDF15 does much more than regulate appetite and body weight," Steinberg said. "We discovered that GDF15 activates a natural brain-to-liver signaling pathway that helps suppress liver inflammation and reduce fibrosis. This changes how we think about the hormone and suggests it may be part of the body's own defense system against chronic liver injury."
By identifying a biological pathway that directly regulates liver inflammation, the researchers suggest that future therapies could potentially target that inflammation alongside existing treatments focused on weight and liver fat. That could be particularly relevant for patients who have already lost significant weight through medication or other means but whose liver inflammation has not resolved.
The study was published August 10, 2026, in Cell Metabolism. Further research will be needed to determine whether the same pathway functions the same way in humans and whether GDF15-based therapies could be developed to target it directly.
