Semaglutide and tirzepatide for MASH

A review published in the journal Digestion on 9 September 2026 maps out where two familiar weight-loss and diabetes drugs now stand as treatments for a liver disease: metabolic dysfunction-associated steatohepatitis (MASH), formerly called NASH.^[1] The authors, Sirinawin Chirapongsathorn and Frank Tacke, open with the fact that changed the field. In August 2025, semaglutide became the first GLP-1 receptor agonist to win FDA accelerated approval for non-cirrhotic MASH.^[2] Tirzepatide, a dual GIP and GLP-1 receptor agonist, has not reached an approval for MASH. Its phase 2 liver data is what has hepatologists watching the next few years closely.

MASH is the more clinically precise name for fat accumulation in the liver that has progressed to inflammation and cell damage, with a subset of patients developing scarring (fibrosis) that can eventually reach cirrhosis. Lifestyle change, mainly weight loss through diet and exercise, remains the starting point for treatment. The review notes that sustained improvement from lifestyle change alone is uncommon, which is the gap a pharmaceutical option is meant to fill.

What works: semaglutide's approval

The FDA's August 2025 approval covers semaglutide injection (Wegovy) for adults with non-cirrhotic MASH and moderate to advanced liver fibrosis. The label describes the indication as stage F2 to F3 fibrosis on the standard histology scale, used together with a reduced-calorie diet and increased physical activity.^[2] The approval is accelerated, meaning it rests on liver-tissue improvement rather than a longer-term clinical outcome, and the manufacturer has an ongoing confirmatory study requirement attached to it.

The evidence behind it is the ESSENCE phase 3 trial. Researchers randomised 1,197 adults with biopsy-confirmed MASH and fibrosis stage 2 or 3, two to one, to weekly semaglutide 2.4 mg or placebo. At 72 weeks, 62.9% of the semaglutide group had resolution of steatohepatitis without the fibrosis getting worse, against 34.3% on placebo. Fibrosis improved by at least one stage without the steatohepatitis worsening in 36.8% of the semaglutide group, against 22.4% on placebo.^[3] Both differences were statistically significant.

What's coming: tirzepatide's fibrosis signal

Tirzepatide has no approved MASH indication yet. What it has is a phase 2 result the review flags as one of the stronger fibrosis signals in the incretin class.^[1] Loomba and colleagues randomised 190 adults with biopsy-confirmed MASH and stage 2 or 3 fibrosis to weekly tirzepatide at 5 mg, 10 mg or 15 mg, or to placebo, for 52 weeks. Resolution of steatohepatitis without worsening fibrosis occurred in 44%, 56% and 62% of the three tirzepatide groups respectively, against 10% on placebo. Fibrosis improved by at least one stage without steatohepatitis worsening in 51% to 55% of the tirzepatide groups, against 30% on placebo.^[4]

Those numbers read larger than semaglutide's ESSENCE results, but the comparison is not a fair one yet. The tirzepatide trial enrolled 190 people; ESSENCE enrolled 1,197. No trial has run tirzepatide and semaglutide head-to-head for MASH the way SURMOUNT-5 did for weight loss in obesity. The review's own framing is that dual GIP and GLP-1 agonism looks encouraging for fibrosis, not that it has been proven superior to a single-receptor GLP-1 drug. A tirzepatide phase 3 MASH trial would be the logical next step toward an FDA filing, and none has been announced as of this writing.

What this is not

This is not a case for self-directed use. Both drugs are prescription-only, and the MASH indication specifically requires biopsy-confirmed disease and a fibrosis stage a clinician determines, not something a patient can assess alone. The FDA's semaglutide approval explicitly excludes cirrhosis: a patient who has already progressed that far is a different case with different treatment options.^[2]

It is also not a settled durability answer. The review says extended follow-up is needed to know whether the fibrosis and steatohepatitis gains hold up over years, and what happens if a patient stops treatment, a question that carries extra weight given that semaglutide and tirzepatide are already known to produce weight regain after discontinuation in their obesity trials.^[1] And it is not a monotherapy that replaces diet and exercise. Both the FDA label and the trial protocols pair the drug with a reduced-calorie diet and increased physical activity, not with the drug alone.

What this means

For readers who already know semaglutide or tirzepatide as weight-loss or diabetes drugs, the point to take away is that the same molecules are being tested and, in semaglutide's case, approved for liver disease on their own separate evidence base. That is a different question from whether weight loss by itself treats MASH. Semaglutide has regulatory backing specific to the liver indication. Tirzepatide has a strong early signal and, for now, nothing more.

If MASH is part of your own picture, the questions that matter, including whether imaging or a biopsy confirms your fibrosis stage and whether either drug fits your history, belong with a hepatologist or endocrinologist rather than with this article. For the wider regulatory and safety picture on either molecule, see the tirzepatide regulation overview and the semaglutide overview.