If you're on Ozempic, Wegovy or Mounjaro — or thinking about starting — and you've heard about liver scans, this guide is for you. It covers what GLP-1 medications do to the liver, when monitoring is worth doing, and what the results mean in plain English.
Quick context: GLP-1 receptor agonists are one of the biggest shifts in metabolic medicine in decades. In the United States, bariatric surgery volumes dropped more than 20% between 2022 and 2024 as GLP-1 prescriptions rose 140%. Australian patterns are following the same shape. And because most GLP-1 patients also have at least one metabolic risk factor for fatty liver disease, the question of liver monitoring matters more than most people realise.
How GLP-1 medications affect the liver
GLP-1 receptor agonists work through three pathways that touch the liver. First, they drive substantial weight loss — 10–20% of body weight in many patients — which reduces liver fat in most cases. Second, GLP-1 receptors are expressed on liver cells; semaglutide has direct hepatic action independent of weight loss. Third, by reducing insulin resistance, GLP-1s lower the metabolic drive that causes fatty liver in the first place.
Phase 3 trial data from ESSENCE (semaglutide for MASH) showed elastography liver stiffness improved more than weight loss alone could explain. Tirzepatide trials show comparable signals. This is why the FDA approved semaglutide for MASH in August 2025 and the AASLD updated guidance in November 2025.
Do I need a liver scan before starting a GLP-1?
Australian GP guidelines (MJA consensus statement, September 2025) recommend a FIB-4 blood test for all patients with metabolic risk factors. If your FIB-4 is in the indeterminate range (1.3–2.67), liver elastography is the next step.
In practice, this means:
- If you have type 2 diabetes, BMI over 30, or metabolic syndrome — get FIB-4 done.
- If your FIB-4 is below 1.3 (or below 2.0 if you're 65+) — routine annual LFTs only.
- If FIB-4 is indeterminate — elastography to clarify whether you have significant fibrosis.
- If FIB-4 is above 2.67 — specialist hepatology referral.
The three GLP-1 medications approved in Australia
| Drug | Indication | AU status | Liver monitoring |
|---|---|---|---|
| Ozempic (semaglutide) | Type 2 diabetes | TGA-approved 2019. PBS-listed for T2D. | Baseline FIB-4 + LFTs. Elastography if indeterminate FIB-4. |
| Wegovy (semaglutide) | Weight management | TGA-approved 2022. PBS listing pending. | Same as Ozempic — semaglutide profile is identical. |
| Mounjaro (tirzepatide) | T2D + weight management | TGA-approved Sept 2024. Wegovy/Mounjaro pricing pressure increasing. | Baseline FIB-4 + LFTs. Higher weight loss = more emphasis on elastography follow-up. |
Monitoring your liver on a GLP-1 — what to expect
A sensible monitoring schedule for an at-risk patient on GLP-1 therapy looks like:
- Baseline: FIB-4, LFTs, weight, BMI, blood pressure. Elastography if FIB-4 indeterminate.
- 3 months: Repeat LFTs. ALT and AST commonly fall — this is expected.
- 6 months: LFTs, weight, blood pressure. Investigate any AST/ALT rises.
- 12 months: Full repeat — FIB-4, LFTs, lipids, weight. Repeat elastography if previously indicated.
Baveno VII criteria suggest a change of ≥5 kPa between elastography measurements is clinically meaningful. Most responders to semaglutide show 4–7 kPa reduction at 12 months in trial data.
MASLD, MASH and the GLP-1 era
MASLD (metabolic-associated steatotic liver disease — formerly NAFLD) affects roughly 30% of Australian adults and 65% of patients with type 2 diabetes. MASH is the inflammatory form: when the liver isn't just fatty, it's actively being damaged. Untreated MASH progresses to fibrosis, cirrhosis and, in some patients, liver cancer.
The combination of GLP-1 weight loss and the August 2025 FDA approval of semaglutide for MASH means Australian GPs and patients now have an evidence-based pharmacological option alongside lifestyle. The challenge is identifying who has MASH — and that's where elastography earns its place.
What elastography measures and why it matters for GLP-1 patients
Liver elastography is a quick, non-invasive ultrasound test that measures liver stiffness in kilopascals (kPa). Stiffer liver = more scarring. It takes 5–10 minutes, requires no needles, and produces an objective number that can be tracked over time.
For GLP-1 patients, the value is two-fold: baseline staging to confirm whether there's significant fibrosis to monitor, and treatment response tracking over time. Both are far easier and cheaper than the alternative (liver biopsy), and far more precise than blood tests alone.
Frequently asked questions
Do I need a liver scan before starting Ozempic?
If you have risk factors for fatty liver disease — type 2 diabetes, BMI over 30, metabolic syndrome — Australian GP guidelines (MJA 2025) recommend a FIB-4 blood test and elastography if FIB-4 is intermediate. Most healthy adults without risk factors don't need a pre-treatment liver scan.
Does Ozempic damage your liver?
No. Trial data and the 2025 AASLD guidance show semaglutide reduces liver fat and inflammation in MASH patients. Transient liver enzyme rises can occur with rapid weight loss but are not the same as drug-induced liver injury.
Can Mounjaro reverse fatty liver disease?
Phase 3 trials of tirzepatide show meaningful reductions in liver fat and improvement in fibrosis markers. Whether the disease is fully reversed depends on baseline severity, ongoing metabolic control, and sustained weight loss.
How often should I monitor my liver on semaglutide?
Baseline FIB-4 and elastography (if FIB-4 is indeterminate or high) before starting, then liver function tests at 3, 6 and 12 months. Repeat elastography is reasonable at 12-monthly intervals while on long-term treatment.
What does an elevated FIB-4 score mean on Ozempic?
FIB-4 above 1.3 (or above 2.0 if you're 65+) suggests possible advanced fibrosis. The next step is elastography to measure actual liver stiffness — not a diagnosis of liver damage on its own.
Can rapid weight loss cause liver damage?
Very rapid weight loss (more than 1.5kg per week sustained) can transiently elevate liver enzymes and, rarely, accelerate fibrosis in susceptible patients. GLP-1 weight loss is usually gradual enough to avoid this — but liver monitoring is still recommended for at-risk patients.
Is semaglutide approved for fatty liver disease in Australia?
Semaglutide is TGA-approved for type 2 diabetes (Ozempic) and weight management (Wegovy). The FDA approved it specifically for MASH in August 2025. TGA approval for the MASH indication is anticipated but not yet finalised.
What liver tests should I have on Mounjaro?
Baseline liver function tests (ALT, AST, GGT, ALP, bilirubin), platelet count for FIB-4 scoring, and elastography if your FIB-4 result is intermediate. Repeat liver enzymes at 3 and 6 months, then annually.
Find a liver elastography clinic near you
Search participating clinics across Australia, or talk to your GP about getting a baseline FIB-4 and elastography before starting GLP-1 therapy.
This page is educational and not medical advice. Always discuss your GLP-1 treatment and liver monitoring with your GP.