Semaglutide and Fatty Liver Disease (MASH): What the Research Shows

Metabolic dysfunction-associated steatohepatitis (MASH, formerly called NASH) is a form of fatty liver disease in which fat build-up comes with liver inflammation and injury, sometimes leading to scarring (fibrosis). It's closely linked with obesity and type 2 diabetes. Research into semaglutide has moved from weight and blood-sugar outcomes to something more direct: what happens inside the liver itself.

What did the phase 3 ESSENCE trial study?

ESSENCE enrolled 1,197 adults with biopsy-confirmed MASH and moderate or advanced fibrosis (stage F2 or F3), randomly assigned to weekly semaglutide 2.4 mg or placebo. The trial is planned to run 240 weeks. A planned interim analysis of the first 800 participants at 72 weeks looked at liver biopsy results:

• MASH resolved without fibrosis getting worse in 62.9% of people on semaglutide versus 34.3% on placebo.
• Fibrosis improved without MASH getting worse in 36.8% versus 22.4%.
• Average weight change was about −10.5% with semaglutide versus −2.0% with placebo.
• Gastrointestinal side effects were more common with semaglutide.

These are specific, biopsy-based outcomes after 72 weeks. They aren't yet evidence of fewer cases of cirrhosis, liver failure or liver-related deaths; the longer part of the trial is designed to answer that. ESSENCE is funded by Novo Nordisk, the manufacturer.

What did the FDA approve?

In August 2025, the US FDA granted Wegovy injection accelerated approval for adults with noncirrhotic MASH and moderate-to-advanced fibrosis (F2–F3), alongside a reduced-calorie diet and more physical activity. "Accelerated approval" means it was approved based on improvements in liver tissue, and continued approval may depend on confirmatory results. As of October 2026, the MASH indication applies to Wegovy injection only; Wegovy tablets are not labeled for MASH, and the indication doesn't cover MASH with cirrhosis. Approvals differ by country.

In November 2025, the American Association for the Study of Liver Diseases (AASLD) updated its guidance on using semaglutide for MASH. It suggests that most candidates can be identified with noninvasive tests (such as liver stiffness scans or blood-based scores) rather than a liver biopsy, and it emphasizes that lifestyle changes remain the cornerstone of care.

Why the disease stage matters

Fatty liver disease spans a wide range, from simple fat build-up to advanced scarring. Results in people with established MASH and F2–F3 fibrosis don't automatically apply to someone with a slightly raised liver enzyme or fat seen on an ultrasound. Working out the stage takes a clinical evaluation, and your care team can explain what your results mean.

What treatment does not replace

People with MASH still need individualized care for diabetes, cholesterol, blood pressure, alcohol use where relevant, other medicines and liver monitoring. Please don't stop other prescribed treatment because a new medicine is in the news. Food still matters too; our practical food guide is a gentle place to start.

Questions for a liver specialist

• What stage of liver disease do I have, and how was it measured?
• Do the trial evidence and the current indication apply to me?
• What monitoring will I need, and how often?
• Which other risk factors should we work on together?

Bring any previous imaging and lab results if you have them.

The new evidence matters because it measures liver disease directly, not just weight loss. The accurate story is a specific research and regulatory milestone, not a universal recommendation for anyone with fatty liver.