MASH / MASLD

MASLD stands for metabolic dysfunction-associated steatotic liver disease — fat accumulating in the liver in someone with metabolic risk factors, without heavy alcohol use. MASH is the more serious form, where that fat is accompanied by inflammation and liver-cell injury, which over years can progress to fibrosis, cirrhosis and liver failure. Both names replaced the older terms NAFLD and NASH.

This is now a labeled use, not a theoretical one. The Wegovy label includes treatment of noncirrhotic metabolic dysfunction-associated steatohepatitis with moderate to advanced fibrosis. The evidence is ESSENCE, a phase 3 trial in which resolution of steatohepatitis without worsening of fibrosis occurred in 62.9% of semaglutide-treated patients versus 34.3% on placebo, and reduction in fibrosis without worsening steatohepatitis in 36.8% versus 22.4%. Mean weight change was −10.5% versus −2.0%.

Tirzepatide has phase 2 data in the same condition. In SYNERGY-NASH, MASH resolution without worsening fibrosis reached 44%, 56% and 62% at 5, 10 and 15 mg against 10% on placebo. That trial was smaller and earlier-stage, and its authors called for larger and longer studies.

The reason this matters to someone focused on weight is that MASLD is common in obesity and usually silent. There is no symptom to notice. It is found through liver enzymes on a routine panel, an incidental finding on imaging, or a fibrosis score calculated from ordinary labs — and finding it changes which medication makes sense.

Ask whether your liver enzymes have ever been elevated, whether a fibrosis assessment such as FIB-4 has been calculated, and whether an elastography scan is warranted. A liver indication can also change a coverage conversation. Our MASH patient guide and liver enzyme explainer go further.