Metabolic dysfunction-associated steatohepatitis, or MASH (the term that has largely replaced the older name NASH, or nonalcoholic steatohepatitis), is a progressive liver disease closely tied to obesity and insulin resistance, and it's become one of the most closely watched new frontiers for GLP-1-class drugs. The regulatory picture here is more specific, and more mixed across individual drugs, than general headlines about "GLP-1s and liver health" might suggest.

What MASH Is

MASH develops when fat accumulates in the liver (metabolic dysfunction-associated steatotic liver disease, or MASLD) and progresses to inflammation and liver cell damage. Left unaddressed, it can progress further to fibrosis, cirrhosis, and liver failure. It's strongly associated with obesity, type 2 diabetes, and metabolic syndrome, which is part of why drugs originally developed for weight loss and diabetes have drawn so much research interest as potential MASH treatments.

Semaglutide: The One With FDA Approval

Semaglutide (sold as Wegovy for this indication) received FDA approval in August 2025 specifically for noncirrhotic MASH with moderate to advanced liver fibrosis, based on the Phase 3 ESSENCE trial. At 72 weeks, 63% of participants on semaglutide achieved MASH resolution without worsening fibrosis, compared with 34% on placebo. Fibrosis improved without MASH worsening in 37% of the semaglutide group versus 22% on placebo, and 33% of participants achieved both outcomes together, compared with 16% on placebo. This made semaglutide only the second FDA-approved treatment for MASH with fibrosis, after resmetirom (Rezdiffra), a different type of drug (a thyroid hormone receptor-beta agonist, not a GLP-1) that was approved earlier.

Tirzepatide: Promising Data, No MASH Approval Yet

Tirzepatide has shown encouraging results in its own dedicated liver trial, SYNERGY-NASH, including histological improvement in liver biopsies among participants with MASH. However, as of this writing, tirzepatide does not have FDA approval specifically for a MASH indication; it remains approved for type 2 diabetes and chronic weight management, with MASH-specific use still investigational and outside its approved label. Prescribing tirzepatide specifically to treat MASH, rather than for its approved uses, would currently be off-label.

Survodutide and Other Candidates Still in Trials

Other drugs in this broader class are being studied specifically for MASH as well. Survodutide, Boehringer Ingelheim and Zealand Pharma's glucagon/GLP-1 dual agonist, is being tested in a dedicated MASH trial called LIVERAGE MASH, separate from its obesity and diabetes trial program. Like tirzepatide, survodutide is not FDA-approved for MASH or for any other use; both remain investigational for this specific indication, and any results from ongoing MASH trials will need to go through the same regulatory review process semaglutide's ESSENCE data did before they could support a label change.

What This Means in Practice

If you have MASH or MASLD and are interested in GLP-1-class treatment, the practical distinction that matters is which drug actually carries an FDA-approved indication for your specific liver condition versus which drugs have only shown promising trial data so far. Right now, that distinction favors semaglutide specifically, not the drug class broadly. Liver disease staging, biopsy results, and overall metabolic health all factor into whether any of these drugs make sense for a given patient, and that's a conversation to have with a hepatologist or treating physician who can review your specific diagnosis and liver fibrosis stage, not something to infer from general information about the drug class.