Wegovy and MASH (fatty liver disease)

MASH in plain language

MASH stands for metabolic dysfunction-associated steatohepatitis, the newer name for what was called NASH. NIDDK, the diabetes, digestive and kidney institute of the US National Institutes of Health, describes it as fat in the liver together with inflammation and liver cell damage. Over time the inflammation can cause scarring, called fibrosis, and in some people it progresses to cirrhosis, a permanently scarred liver, which raises the risk of liver cancer ^[7].

NIDDK estimates that 1.5% to 6.5% of US adults have this form of fatty liver disease. It is more likely with overweight or obesity, insulin resistance or type 2 diabetes, abnormal blood fats and metabolic syndrome, and having more of these conditions raises the chance of the inflamed form ^[7][8]. It is often silent: NIDDK notes that people may have no symptoms even with cirrhosis, or may feel tired or notice discomfort in the upper right abdomen ^[8].

Fibrosis is graded in stages. The Wegovy® indication covers stages F2 and F3, which the label calls moderate to advanced, and explicitly excludes cirrhosis ^[1].

How the liver is assessed

NIDDK explains that doctors use blood tests, imaging and sometimes a liver biopsy. Raised liver enzymes such as ALT and AST can raise suspicion, and routine blood results can feed scores such as FIB-4 that help identify or rule out advanced fibrosis. Ordinary scans show fat but not inflammation or scarring, while elastography measures liver stiffness, which may be a sign of fibrosis ^[9].

The Wegovy® trial needed a biopsy. The label also reports non-invasive measures at the start: a median FIB-4 of 1.6, an enhanced liver fibrosis (ELF) score of 9.9 and, in the 79% who had it, a transient elastography reading of 10.9 kPa ^[1]. Which tests you need, and how your stage is decided, are for your liver specialist.

What the indication says

• Who: adults with noncirrhotic MASH and moderate to advanced fibrosis, consistent with stages F2 to F3 ^[1].
• With what: alongside a lower-calorie diet and more physical activity, as with the other Wegovy® uses ^[1].
• Which form: the injection only. The tablets are approved for weight and heart risk, and the label says their safety in MASH has not been established. The same applies to the 7.2 mg injection dose ^[1].
• Which dose the label describes: a maintenance dose of 2.4 mg once weekly, which can be lowered to 1.7 mg if 2.4 mg is not tolerated ^[1]. Your dose is your prescriber’s decision.
• Not for children: the Medication Guide says it is not known whether Wegovy® is safe and effective for MASH in people under 18 ^[1].

US, EU and Canada side by side

The three regulators did not reach the same place. The table shows what each document said when we checked on 20 October 2026.

What accelerated approval means

The label states that this indication was approved under accelerated approval, based on improvement in MASH and fibrosis, and that continued approval may depend on a confirmatory trial verifying clinical benefit ^[1]. FDA’s announcement adds that the use had received breakthrough therapy designation ^[5].

FDA explains that accelerated approval allows a medicine for a serious condition to be approved on a surrogate endpoint: a measurement thought to predict real benefit without being that benefit itself. Here the surrogate is what liver biopsies show. If later trials fail to confirm benefit, FDA can withdraw the approval or change the labeled indication ^[6]. FDA’s announcement of the approval adds that the trial will continue to 240 weeks to see whether biopsy improvements translate into fewer deaths, liver transplants and other liver events ^[5]. Canada uses a similar route, called a notice of compliance with conditions, and asks that patients be told about the nature of the authorization ^[4].

The trial behind it

The label calls it Study 11; it is registered as ESSENCE (NCT04822181). It is a 240-week, randomized, double-blind, placebo-controlled trial. To enter, people needed a liver biopsy showing MASH with fibrosis stage 2 or 3 and a minimum disease activity score ^[1][4]. The published report describes 1,197 participants in all, with the week-72 analysis based on the first 800 ^[2].

Those 800 adults were randomized two to one: 534 to Wegovy® and 266 to placebo, on top of standard care for related conditions and lifestyle counseling. The dose was raised to 2.4 mg once weekly over the first 16 weeks, and people who could not tolerate it could stay on a lower dose ^[1].

The median participant was 57 years old with a BMI of 34 kg/m²; 57% were women. Fibrosis was stage 3 in 69% and stage 2 in 31%. More than half (56%) had type 2 diabetes, and 7% had a BMI below 25 kg/m². Each biopsy was read independently by two pathologists, with a third settling disagreements ^[1].

Results at week 72

The two main endpoints are in the first two rows; the third is a secondary endpoint. All three differences were statistically significant ^[1].

Weight, liver enzymes and the mechanism

Average weight loss at week 72 was 10.5% on Wegovy® versus 2% on placebo. The label also reports a trend toward greater reductions in the liver enzymes ALT and AST in the Wegovy® group from week 12 onward ^[1]. The published report adds that bodily pain scores did not differ between the groups ^[2].

The label is candid about the mechanism: for MASH, how semaglutide works in humans is not fully understood and may involve several pathways driven by weight loss and other factors. Animal results are mentioned, with the caveat that the link between animal MASH and the human disease has not been fully established ^[1].

Safety in the MASH trial

• The safety analysis included 1,195 adults with MASH, with a median exposure of 95.3 weeks on Wegovy® and 83.1 weeks on placebo; the most common reactions matched those seen with the other Wegovy® uses, led by stomach-related effects ^[1].
• Fractures occurred in 4.4% on Wegovy® versus 3.3% on placebo ^[1].
• Lipase above three times the upper limit of normal occurred in 4.7% versus 1.3%. The label says the meaning of such rises is unknown without other signs of pancreatitis ^[1].
• In people with MASH and type 2 diabetes, the Canadian monograph reports severe low blood sugar in 2.2% on Wegovy® and 0.5% on placebo ^[4].
• The label notes limited information for people with MASH and a BMI below 25 kg/m². About a quarter of those on Wegovy® were 65 or older, with no overall differences in safety or effectiveness by age ^[1]. Canada adds that experience in people with compensated cirrhosis was limited ^[4].
• For pregnancy, the label says MASH with advanced fibrosis itself may carry risks, and that Wegovy® for MASH should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus ^[1].
• All of the label’s general warnings, including the boxed warning on thyroid C-cell tumors, apply to this use too ^[1].

What the indication does not cover

The label is specific about what falls outside: cirrhosis, people under 18, the tablets and the 7.2 mg dose ^[1]. Simple fatty liver without inflammation and scarring is also outside the indication, and NIDDK notes that this milder form usually does not progress to liver damage ^[7].

The trial is also still running. Until its outcome results are reported, the evidence is about what biopsies showed at 72 weeks, not about fewer liver complications ^[1][5].

Wegovy® is a registered trademark of Novo Nordisk A/S. PepLabo is not affiliated with or endorsed by Novo Nordisk.