GLP-1s and Fatty Liver (MASH)

MASH — metabolic dysfunction-associated steatohepatitis, formerly called NASH — is a form of fatty liver disease that can progress to cirrhosis. In 2025, semaglutide 2.4mg received approval for the treatment of MASH with liver fibrosis in adults, based on the ESSENCE trial. Here's what that means.

What is MASH (fatty liver disease)?

The liver normally contains a small amount of fat. When fat accumulates beyond a certain level — typically in the context of obesity, type 2 diabetes, or metabolic syndrome — it can cause a condition broadly called fatty liver disease.

The terminology has evolved:

• MASLD (metabolic dysfunction-associated steatotic liver disease) is the current umbrella term, replacing the older NAFLD
• MASH (metabolic dysfunction-associated steatohepatitis) is the inflammatory form, previously called NASH — where fat accumulation triggers liver cell inflammation and damage
• MASH can progress to fibrosis (scarring of liver tissue) and, in advanced cases, cirrhosis

Many people have MASLD or early-stage MASH without knowing it, as it often causes no obvious symptoms until the disease is more advanced. Diagnosis typically involves blood tests, imaging, and in some cases a liver biopsy.

What did the ESSENCE trial show?

The ESSENCE trial was a large, randomised, placebo-controlled trial that studied semaglutide 2.4mg (the dose used in Wegovy) in adults with MASH and liver fibrosis.

The trial showed that treatment with semaglutide 2.4mg led to resolution of MASH in many participants — meaning the inflammatory component of the disease was no longer detectable at biopsy — as well as improvements in liver fibrosis in a meaningful proportion of participants.

These findings were of sufficient scale and quality to support a specific FDA approval for this indication in 2025. This was a significant development: MASH has historically had limited pharmacological treatment options beyond lifestyle intervention.

What does the 2025 approval mean?

The 2025 FDA approval means that semaglutide 2.4mg (Wegovy) is now an approved treatment for adults with MASH and liver fibrosis — not just for weight management. This is a separate regulatory indication from the weight-loss approval.

In practice, this means:

• Prescribers can now prescribe semaglutide 2.4mg specifically for MASH with fibrosis
• Insurance coverage pathways may differ depending on whether the prescription is for weight management or MASH
• Treatment of MASH with semaglutide should be under the supervision of a clinician — ideally one with hepatology experience

This does not mean anyone with fatty liver should start a GLP-1 medication without clinical assessment. MASH is a serious condition and treatment decisions require proper diagnosis and clinician oversight.

Is this the same as the weight-loss approval?

No. The MASH approval is a separate indication. Wegovy was already approved for chronic weight management; the 2025 approval adds MASH with liver fibrosis as a distinct indication.

The dose is the same — semaglutide 2.4mg — but the clinical context is different. People prescribed semaglutide for MASH are typically being treated for a liver condition, not solely for weight management, though weight loss often accompanies the treatment and may contribute to the liver benefit.

It is also important to note that Ozempic — also semaglutide, but at a lower dose (up to 2mg) — is approved for type 2 diabetes, not for MASH. The MASH approval is specific to the 2.4mg dose (Wegovy). Speak to your clinician about which medication and which indication applies to your situation.

Frequently asked questions

What is the difference between fatty liver, NAFLD, MASH and NASH?
These terms overlap. NAFLD (non-alcoholic fatty liver disease) was the older umbrella term. MASH (metabolic dysfunction-associated steatohepatitis) is the new preferred term for the inflammatory form previously called NASH. It's a more advanced stage of fatty liver that can lead to fibrosis and cirrhosis.

Was semaglutide already known to help with fatty liver?
Earlier studies suggested benefit, but the ESSENCE trial provided the large-scale evidence that led to the specific FDA approval for MASH with fibrosis in 2025.

Can I use Ozempic for fatty liver?
Ozempic is semaglutide but at a lower dose (up to 2mg) approved for type 2 diabetes — not for MASH. The MASH approval is for semaglutide 2.4mg (Wegovy). Speak to your clinician about what's appropriate for your situation.

Do I need a liver biopsy to be diagnosed with MASH?
Historically yes, but non-invasive tests are increasingly used. Your clinician or hepatologist determines the appropriate diagnostic approach.