Wegovy liver side effects: what the evidence shows and what to watch for

What trial data and the MHRA approval tell us about semaglutide and the liver

The most striking recent development is that, far from causing liver harm, the MHRA conditionally approved Wegovy in July 2026 for use in adults with MASH (metabolic dysfunction-associated steatohepatitis) — a progressive inflammatory liver disease linked to obesity and excess liver fat. That conditional approval, which you can read about on GOV.UK, followed trial data showing that semaglutide reduced liver inflammation and fibrosis scores compared with placebo in adults with moderate-to-advanced fibrosis. Liver enzymes such as ALT and AST, which doctors use as markers of liver cell injury, were not raised to concerning levels in the large STEP programme trials, which enrolled thousands of adults with obesity.

This does not mean semaglutide is without abdominal risk. The gallbladder sits directly beneath the liver, and gallstones are a recognised side effect across GLP-1 receptor agonist medicines. Gallstone formation appears to relate to rapid weight loss itself as much as to the drug directly. Symptoms (upper right abdominal pain, bloating, pain after eating fatty foods) can feel liver-adjacent, so people sometimes worry about their liver when what's happening is a gallbladder issue. These two are distinct, but both are worth telling your prescriber about promptly if they arise. The broader Wegovy side effects picture, including gastrointestinal and gallbladder effects, is worth reviewing before you start treatment.

The MHRA's prescribing guidance and the semaglutide Summary of Product Characteristics note that liver function should be considered as part of the overall clinical assessment. If you have pre-existing liver disease outside of MASH, your prescriber will weigh that individually.

The pancreatitis signal: why abdominal pain always needs assessing

In January 2026 the MHRA issued a Drug Safety Update for GLP-1 medicines, including semaglutide, highlighting acute pancreatitis as an infrequent but potentially serious event. The pancreas sits behind the stomach and close to the liver; inflammation there produces a distinctive pain, severe, persistent, often spreading from the abdomen through to the back, sometimes with vomiting. If you develop that kind of pain while taking Wegovy, stop and get emergency care; do not wait to see whether it settles. You can report any suspected side effect, including this one, through the MHRA's Yellow Card scheme.

Pancreatitis-related pain is different from typical GI side effects. Nausea, loose stools, and indigestion are common (particularly when starting treatment or after a dose increase) and usually settle within a week or two. Severe mid-abdominal or back pain that persists and worsens is a different signal entirely. Our clinical team covers this distinction in more detail on the side effects from Wegovy page, which also addresses rarer presentations. For anything that concerns you between consultations, the contact page lists how to reach aftercare seven days a week.

Pre-existing liver disease: what remains uncertain and who to talk to

MASH apart, the picture for people with other chronic liver conditions is less well characterised. Most Wegovy trials excluded participants with significant hepatic impairment, so the evidence base for that subgroup is limited. If you have cirrhosis, hepatitis B or C, drug-induced liver injury, or alcohol-related liver disease, the question of whether Wegovy is appropriate is one for your hepatologist or gastroenterologist to answer alongside your prescriber, not something to work out alone.

Wegovy is not recommended during pregnancy or breastfeeding, and is not suitable for those trying to conceive; if your situation falls into any of these categories your prescriber will discuss alternatives. It is also not licensed for anyone under 18. Beyond those absolute limits, suitability depends on your individual clinical picture, including any history of liver problems, and it is worth knowing that some people experience no side effects on Wegovy at all, which can itself prompt questions about whether the medication is working as expected. Some people do report a raised temperature, and our page on whether Wegovy side effects can include fever explains what to watch for and when to seek advice.

Detailed eligibility is assessed at consultation. At nume, a GPhC-registered Independent Prescriber reads your answers on the same day you submit them, a real clinician, not an automated system. If Wegovy is right for you and treatment is approved, your medication arrives the next working day via DPD in plain, unbranded packaging, so there is nothing to identify the contents at the door. You can explore what treatment involves on the weight-loss treatments page, or read more about semaglutide as a whole on our Wegovy overview. Questions about cost are answered on the Wegovy price page, including what's included in the one-off fee.