Key Numbers from the ESSENCE Trial
(vs 34.3% placebo)
(vs 22.4% placebo)
(Wegovy formulation)
in ESSENCE trial
In August 2025, the FDA granted accelerated approval to semaglutide (the Wegovy formulation) for treating MASH; previously called NASH; in adults with moderate-to-advanced liver fibrosis (stages F2–F3). ref 1 This AASLD practice guidance provides practical recommendations for doctors on how to identify eligible patients, start treatment, and monitor their progress.
Who Qualifies for Semaglutide?
The ESSENCE trial enrolled patients with biopsy-confirmed MASH and F2–F3 fibrosis. However, AASLD makes clear that liver biopsy is not required in clinical practice. ref 6 Instead, non-invasive tests (NITs) are recommended to determine eligibility. The FDA approval itself does not require a liver biopsy. ref 56
AASLD recommends a sequential approach: start with FIB-4 to rule out advanced fibrosis (a score below 1.3 excludes advanced fibrosis in 99% of patients ref 7), then use elastography or blood-based biomarkers to stage the disease. Importantly, FIB-4 should not be used as a single eligibility test for semaglutide. ref 8
NIT Thresholds for Semaglutide Eligibility
| Test | Recommended Range | May Be Used (individualized) | Not Recommended |
|---|---|---|---|
| FibroScan (VCTE) | 8 – 15 kPa ref 9 | 15 – 20 kPa ref 12 Must rule out cirrhosis |
> 20 kPa ref 13 Suggests cirrhosis |
| MRE | 3.1 – 4.4 kPa ref 15 | 4.4 – 5.0 kPa | > 5.0 kPa |
| ELF Score | 9.2 – 10.5 ref 17 | 10.5 – 11.3 | > 11.3 |
For patients with values in the "may be used" zone, doctors should exclude cirrhosis using a second confirmatory NIT, cross-sectional imaging (looking for nodular liver contour or signs of portal hypertension), or a platelet count below 150,000/mm³. ref 12
Monitoring During Treatment
Semaglutide showed a favorable liver safety profile in ESSENCE — no participants stopped treatment due to elevated liver enzymes. ref 20 AASLD recommends hepatic function panels only as clinically indicated, rather than on a strict schedule. ref 21
Before Starting Treatment
Your doctor should obtain baseline liver function tests, a fibrosis measurement (VCTE, MRE, or ELF), a steatosis measurement (such as CAP or MRI-PDFF), and check for thyroid nodules. Patients with type 2 diabetes should have a retinal exam if not done in the past 12 months. Active suicidal ideation is a contraindication for initiation. ref 22
During Treatment
Monitor for GI symptoms (nausea, vomiting, diarrhea, constipation), abdominal pain, depression, or suicidal thoughts. As clinically indicated: pregnancy testing, hepatic function panel, and right upper quadrant ultrasound if gallstone symptoms arise.
Side Effects and Safety
Overall, 86.2% of semaglutide-treated patients had at least one adverse event (vs 79.7% placebo) ref 23, but discontinuation rates were similar between groups (2.6% vs 3.3%). ref 24
GI Side Effects (Most Common)
Nausea affected about 36% of patients, diarrhea 27%, constipation 22%, and vomiting 19%. ref 25 These were generally mild to moderate and resolved over time. ref 26 Strategies to manage them include gradual dose titration, eating smaller low-fat meals, staying hydrated, and increasing fiber intake. ref 27
Serious but Rare Risks
Clinicians should watch for: acute kidney injury from dehydration during GI episodes ref 28; symptomatic gallbladder disease (37% increased risk in a meta-analysis of 76 RCTs) ref 29; pancreatitis (discontinue immediately if suspected); thyroid C-cell tumors (contraindicated in patients with MTC or MEN2 history) ref 30; retinopathy progression in diabetics ref 34; and lean mass loss — about 39% of total weight lost, with appendicular skeletal muscle declining 9–10% over two years. ref 35 Resistance exercise and protein intake of 1.2–1.5 g/kg/day are recommended. ref 36
How Doctors Assess Response
At 72 weeks, AASLD suggests the following benchmarks for a beneficial response. ref 40 These should be assessed using the same NIT used at baseline.
| Marker | Beneficial Response Threshold |
|---|---|
| VCTE (FibroScan) Stiffness | Decrease ≥ 30% from baseline ref 41 |
| MRE Stiffness | Decrease ≥ 20% from baseline ref 40 |
| MRI-PDFF (Liver Fat) | Decrease ≥ 30% from baseline |
| ALT | Decrease ≥ 17 U/L or ≥ 20% ref 40 |
| ELF Score | Decrease ≥ 0.5 from baseline ref 42 |
If ALT or NIT values worsen, non-response should be suspected. In the ESSENCE trial, 37.1% did not resolve MASH and 63.2% did not improve fibrosis by week 72. ref 43
Benefits Beyond the Liver
MASH patients face elevated risks not just for liver disease, but also for cardiovascular disease — the leading cause of death in this group. ref 44 Semaglutide has FDA-approved indications addressing several of these comorbidities.
Weight loss: The STEP trials showed average weight reduction of 9.6–16% ref 46, with 45–75% of participants achieving ≥10% loss — the threshold associated with fibrosis reversal. ref 47 However, stopping semaglutide reverses these improvements, indicating ongoing treatment is necessary. ref 48
Cardiovascular protection: The SELECT trial demonstrated a 1.5% absolute reduction in major cardiovascular events in over 17,000 non-diabetic individuals over ~40 months. ref 49 These benefits appeared regardless of starting weight or total weight lost. ref 50
Kidney protection: The FLOW trial showed a 24% relative risk reduction in kidney failure and CV death in 3,533 adults with T2DM and CKD on semaglutide 1.0 mg weekly. ref 51
Lifestyle modification — including nutrition, exercise, and behavior change — remains the cornerstone of MASLD management alongside any pharmacotherapy. ref 39