Fatty liver is the condition most likely to be discovered by accident on the way to a weight-loss prescription: an ultrasound ordered for something else, a raised ALT on a routine panel, a note that the liver looks bright. The disease behind those findings now has a drug in this class licensed against it, which is a genuine first and a much narrower claim than it sounds. What the trials measured was tissue under a microscope, and the tissue answered two different questions differently. That distinction matters more than anything on the semaglutide price boards.
Two endpoints, not one
Metabolic dysfunction-associated steatotic liver disease, or MASLD, is fat in the liver. Metabolic dysfunction-associated steatohepatitis, or MASH, is fat plus inflammation and injured cells, and it is the form that scars. Every trial in this field therefore scores a biopsy twice: resolution of steatohepatitis, which is the inflammation clearing, and fibrosis stage, which is the scarring receding. A drug can move one and not the other, and the first semaglutide trial did exactly that.
Fibrosis is the endpoint that predicts what happens to a person. Scarring stages from F0 to F4, and F4 is cirrhosis. Resolution of inflammation is the endpoint that moves first and the one a press release leads with.
The phase 3 result
ESSENCE randomized 1,197 patients with biopsy-defined MASH and stage 2 or 3 fibrosis, in a 2:1 ratio, to once-weekly semaglutide 2.4 mg or placebo for 240 weeks. A planned interim analysis at week 72 covering the first 800 patients is what has been published.[1]
Resolution of steatohepatitis without worsening of fibrosis occurred in 62.9% of 534 patients on semaglutide against 34.3% of 266 on placebo, an estimated difference of 28.7 percentage points (95% CI, 21.1 to 36.2). Reduction in liver fibrosis without worsening of steatohepatitis occurred in 36.8% against 22.4%, a difference of 14.4 percentage points (95% CI, 7.5 to 21.3). Both endpoints were met at P < 0.001. Mean weight change was −10.5% against −2.0%.[1]
One prespecified outcome did not separate: mean changes in bodily pain scores did not differ significantly between the groups.[1] Gastrointestinal adverse events were more common on semaglutide, the same profile described in the side-effect article.
The earlier trial resolved inflammation and left the scarring alone
The phase 2 trial is the reason the fibrosis number in ESSENCE is worth reading twice. It randomized 320 patients with biopsy-confirmed steatohepatitis and stage F1, F2 or F3 fibrosis to once-daily semaglutide at 0.1, 0.2 or 0.4 mg or matching placebo for 72 weeks.[2]
Resolution with no worsening of fibrosis reached 59% in the 0.4 mg group against 17% on placebo (P < 0.001). The fibrosis endpoint did not follow: improvement of at least one stage occurred in 43% on the highest dose and 33% on placebo, P = 0.48.[2] Mean weight loss was 13% against 1%. One trial, one cohort, one dose: the inflammation endpoint cleared placebo by 42 percentage points and the scarring endpoint by 10 points that could not be distinguished from chance.
That trial also recorded something no summary should drop. Malignant neoplasms were reported in three semaglutide recipients (1%) and in none on placebo, and neoplasms of any kind in 15% of semaglutide patients against 8% on placebo, with no pattern in any specific organ.[2] It is a small imbalance in a 320-patient trial rather than a finding, and it is not the sort of number a page that quotes the 59% gets to omit.
In cirrhosis the result points the other way
The population most likely to assume a liver drug is for them is the one it has failed in. A phase 2 trial enrolled 71 patients with biopsy-confirmed steatohepatitis-related compensated cirrhosis — stage F4 — and a body-mass index of 27 or more, randomized 2:1 to once-weekly semaglutide 2.4 mg or placebo for 48 weeks.[3]
Improvement of one fibrosis stage or more without worsening of steatohepatitis occurred in five of 47 patients (11%) on semaglutide and seven of 24 (29%) on placebo — an odds ratio of 0.28 (95% CI, 0.06 to 1.24; p = 0.087). Resolution did not differ either (p = 0.29).[3] The confidence interval crosses 1, so this is a null result rather than evidence of harm; what it is not is a smaller version of ESSENCE. The AASLD practice guidance states plainly that semaglutide is not approved to treat MASH cirrhosis.[4]
What the approval actually covers
The Wegovy formulation received accelerated approval in August 2025 for MASH with moderate-to-advanced fibrosis, corresponding to stages F2 and F3, on the strength of the ESSENCE interim histology. Final approval awaits long-term outcome data.[4] Accelerated approval rests on a surrogate endpoint — biopsy appearance — and not yet on decompensation, transplant or death.
Patient selection under that guidance runs through non-invasive tests rather than biopsy: transient elastography between 8 and 15 kPa, magnetic resonance elastography between 3.1 and 4.4 kPa, or an enhanced liver fibrosis score between 9.2 and 10.5.[4] None of those is a questionnaire, and none of them is ordered at checkout. The guidance also names the risks to monitor, including gallbladder disease and pancreatitis — covered in the gallbladder article — and lean mass loss, covered in the muscle article.
Tirzepatide has the histology and not the indication
SYNERGY-NASH randomized 190 participants with biopsy-confirmed MASH and stage F2 or F3 fibrosis to once-weekly tirzepatide at 5, 10 or 15 mg or placebo for 52 weeks, with 157 evaluable biopsies at the end.[5]
Resolution without worsening of fibrosis was 10% on placebo, 44% at 5 mg, 56% at 10 mg and 62% at 15 mg, all at P < 0.001. Fibrosis improvement of at least one stage was 30% on placebo against 55%, 51% and 51%, with confidence intervals whose lower bounds sat at 5, 1 and 1 percentage points.[5] That is a phase 2 dose-finding trial, not a registration trial, and tirzepatide carries no MASH indication. Anyone weighing the two molecules against each other should read the molecule comparison with that asymmetry in front of them.
Why the headline percentages cannot be ranked
Four trials, four placebo groups, four different rates of getting better on nothing: 34.3% in ESSENCE,[1] 17% in the phase 2 semaglutide trial,[2] 10% in SYNERGY-NASH[5] and 9.7% in the phase 3 trial of resmetirom.[6] Biopsy scoring is subjective, entry criteria differ, and a placebo arm that improves in a third of its patients is not measuring the same thing as one that improves in a tenth.
Resmetirom is the other approved agent and it is not in this class at all. Its phase 3 trial randomized 966 analyzable patients with stage F1B, F2 or F3 fibrosis to 80 mg, 100 mg or placebo; resolution reached 25.9% and 29.9% against 9.7%, and fibrosis improvement 24.2% and 25.9% against 14.2%, all at P < 0.001.[6] Set against ESSENCE those percentages look far smaller, and the two placebo arms differ by twenty-five points. The guidance notes that the combination of resmetirom with semaglutide has not been studied.[4]
What a cash-pay buyer is actually holding
Every figure above was produced with branded, FDA-approved product at labeled doses, in patients enrolled on the strength of a liver biopsy. Most sellers in this market dispense compounded semaglutide or tirzepatide. Compounded drugs are not FDA-approved, and are not reviewed by the FDA for safety, efficacy or quality before they are dispensed — the distinction set out in the compounding article. A MASH indication granted to one branded formulation is not a property a vial acquires by sharing a molecule name.
The practical reading is narrow and worth stating. Suspected fatty liver is a reason to be assessed by someone who can order elastography and read it, not a reason to buy faster. The dose that carries the histology is 2.4 mg weekly, which is the top of the ladder in the titration article, and the trials ran it for 72 weeks. Whether an online program can reach that dose and hold it for that long is a question about the program, and the way this site establishes that sort of figure is described in the methodology.