Foundayo Liver Safety: Is Foundayo Safe for Your Liver? The Evidence Explained

• What the pooled liver safety analysis of more than 11,000 trial participants actually found
• Why liver enzymes tended to fall, not rise, on Foundayo
• The liver monitoring regulators have asked for, explained honestly
• Online consultation with UK-registered prescribers if you have a liver condition or concerns

If you are considering Foundayo (orforglipron) and have read about liver safety, you are right to ask. Several other experimental oral GLP-1 tablets were stopped during development because of liver problems, and many people who are offered weight management medicines already have fatty liver changes. So the question is reasonable, and it has been studied directly.

The short answer is reassuring. A dedicated analysis of seven phase 3 trials, covering more than 11,000 people, found no confirmed cases of liver injury caused by orforglipron, and liver enzyme levels on average went down, not up. The US FDA has also required additional safety data on potential drug-induced liver injury as part of its post-approval requirements. This is US regulatory information and is separate from the UK's regulatory framework.In the UK, Foundayo is authorised by the MHRA and is subject to additional monitoring

Key things to know

• A pooled analysis of 11,220 trial participants, followed for up to 104 weeks, found no cases meeting the criteria for medicine-induced liver injury with orforglipron
• Six participants receiving orforglipron (0.1%) and six receiving comparator treatments (0.1%) met the laboratory threshold that triggered review for possible drug-induced liver injury; all six orforglipron cases had alternative explanations.
• Average liver enzyme levels fell on orforglipron, most likely because weight loss improves fatty liver
• Liver problems are not listed as a side effect in the UK patient leaflet
• The US FDA has required additional safety data on potential drug-induced liver injury, including further assessment of liver-safety data from the clinical programme.This is a US regulatory requirement; UK safety monitoring is governed separately by the MHRA.
• People with severe liver disease were not well represented in the clinical programme, so individual assessment is important.

Why Liver Safety Is a Fair Question for Foundayo by Eli Lilly

Foundayo is a first-in-class small-molecule, non-peptide GLP-1 receptor agonist. That design is what allows it to work as a tablet with no food or water rules. But small-molecule medicines are handled differently by the body from peptide medicines like Mounjaro and Wegovy injections, and some are processed by the liver.

The question gained attention because at least two other experimental oral small-molecule GLP-1 medicines, developed by another manufacturer, were discontinued after liver-related findings in their trials. That history made liver safety one of the most closely watched issues for orforglipron, and it is why a dedicated analysis was carried out and published.

There is a second reason the question matters. Obesity and type 2 diabetes are strongly linked to fatty liver disease, now called metabolic dysfunction-associated steatotic liver disease (MASLD). The NHS estimates that up to 1 in 3 people in the UK have early signs of fatty liver. Many people who might take Foundayo will already have some changes in their liver tests before they start.

What the Dedicated Liver Safety Analysis Found

In 2026, researchers published a pooled analysis of liver safety across the orforglipron phase 3 programme in the peer-reviewed journal Diabetes, Obesity and Metabolism.

Who was included

The analysis covered 11,220 participants from seven phase 3 trials in people with obesity or overweight, type 2 diabetes, or both. Of these, 6,920 took orforglipron and 4,300 took a comparison treatment: placebo, oral semaglutide, dapagliflozin or insulin glargine. Participants were followed for up to 104 weeks, including safety follow-up.

How liver injury was checked

Researchers tracked liver enzymes (ALT and AST) and bilirubin throughout the trials. They also screened for the combination doctors use to flag possible serious liver injury, known as Hy's Law.

Hy's Law is a regulatory signal used to identify possible serious drug-induced liver injury. It involves marked elevations in liver enzymes together with elevated bilirubin, after alternative explanations have been considered.

The key results

Six people on orforglipron and six on comparison treatments had the combination of liver test changes that triggered further review. When the orforglipron cases were examined, every one had another explanation. Reported causes included gallbladder and bile duct disease, acute viral hepatitis, Gilbert syndrome (a common, harmless inherited condition that raises bilirubin) and alcohol-related liver disease. None met the criteria for liver injury caused by the medicine.

The authors concluded that orforglipron was not associated with medicine-induced liver injury, and that its liver safety profile was similar to placebo and the active comparison medicines. Results were consistent whether people started with normal or raised liver enzymes.

Understanding Liver Blood Test Terms

Liver safety results are reported using a handful of standard blood tests, and knowing what they mean makes the findings above easier to follow.

ALT and AST

Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are enzymes found inside liver cells. When liver cells are inflamed or stressed, more of these enzymes leak into the blood. Mild rises are common and can be caused by fatty liver, alcohol, recent intense exercise, viral infections and some medicines. On their own, small rises rarely mean serious damage.

Bilirubin

Bilirubin is a yellow pigment made when old red blood cells are broken down. The liver processes it and passes it into bile. A raised bilirubin level can mean the liver is not clearing it properly, that bile flow is blocked, for example by a gallstone, or simply that someone has Gilbert syndrome.

Upper limit of normal

Each laboratory sets a normal range for every test. Results are often described as multiples of the upper limit of normal, so "three times the upper limit" means three times the highest value expected in healthy people. It is the combination and size of changes, rather than a single slightly raised result, that concerns doctors.

Why Liver Enzymes Went Down, Not Up

One of the most useful findings is the direction of change. On average, ALT and AST, the liver enzymes that rise when liver cells are stressed, fell during treatment with orforglipron.

One plausible explanation is the weight loss and associated metabolic improvements seen with orforglipron treatment. In fatty liver disease, excess fat inside liver cells causes low-grade inflammation, which pushes liver enzymes up. Losing weight reduces liver fat, and enzyme levels typically improve as a result. The authors described the enzyme pattern as consistent with the metabolic benefits of weight loss.

Mild enzyme rises still happen in some people, as they do in any large group over time. The NIH's LiverTox reference reports mild liver enzyme elevations in 39% of people on orforglipron compared with 41% on placebo, which again shows no excess.

What the UK Leaflet Says About the Liver

Foundayo's UK patient leaflet, revised in August 2026, does not list liver damage or liver injury among its side effects. It does list gallbladder problems. Gallstones are a common side effect, affecting up to 1 in 10 people, and the leaflet asks you to tell your doctor about pain in the upper stomach, yellowing of the skin or eyes, pale stools or fever.

This link is worth understanding.Gallstones can obstruct the bile ducts and cause jaundice or abnormal liver blood tests. These symptoms therefore need medical assessment rather than being assumed to represent either liver injury or a gallbladder problem. Gallbladder and bile duct disease was one of the alternative explanations found in the liver safety analysis. So if you develop jaundice or upper stomach pain while taking Foundayo, get it checked promptly, whatever the cause turns out to be.

What Regulators Are Still Monitoring

Being honest about the evidence means covering what is not yet known. When the FDA approved Foundayo in April 2026, its approval letter requested more safety data on Foundayo, including liver-related follow-up, cardiovascular monitoring and further post-marketing studies on delayed stomach emptying. Foundayo also faces scrutiny over cardiovascular and liver safety signals, although this reflects regulatory caution and ongoing assessment rather than confirmed harm.

This does not mean a liver problem was found. Eli Lilly must gather more safety data on Foundayo as part of post-marketing monitoring for possible liver-related effects. In the US, the FDA required completion of the ongoing ACHIEVE-4 trial and submission of additional safety data concerning major cardiovascular events and potential drug-induced liver injury, including Hy's Law assessments. The FDA's approval documents also requested enhanced post-marketing surveillance for serious unexpected cases of drug-induced liver injury. This does not mean that the FDA identified confirmed liver injury caused by orforglipron. Rather, these requirements provide additional safety surveillance as experience with the medicine grows.

In the UK, Foundayo is authorised by the MHRA and remains under additional monitoring, indicated by the black triangle. The MHRA says it will keep the medicine's safety and effectiveness under close review.

Foundayo and Existing Liver Conditions

Fatty liver (MASLD)

People with common, obesity-related fatty liver changes were not excluded from the trials, provided their liver enzymes were below set limits: less than three times the upper limit of normal in the weight management trials, and no more than five times in the type 2 diabetes trials. The analysis found consistent results in people who started with raised enzymes. Weight loss can improve metabolic dysfunction-associated steatotic liver disease (MASLD), but Foundayo is not specifically being presented here as a treatment for MASLD.

More significant liver disease

People with severe liver disease were not well represented in the clinical trials, so evidence is limited in this group. The UK prescribing information states that no dose adjustment is required for mild or moderate hepatic impairment, but orforglipron is not recommended in patients with severe hepatic impairment. If you have cirrhosis, hepatitis or another diagnosed liver condition, discuss it with your prescriber before treatment.

Medicines that affect how Foundayo is processed

Some medicines can alter orforglipron exposure by affecting the enzymes or transport pathways involved in its metabolism and transport. Tell your prescriber about all medicines, herbal products and supplements you take.

Protecting Your Liver While Taking Foundayo

• Tell your prescriber about any liver condition, past hepatitis, or abnormal liver tests before you start
• Keep alcohol within UK low-risk guidelines of no more than 14 units a week, spread over several days, or less if you have a liver condition
• Avoid taking herbal remedies or supplements without checking with a pharmacist, as some can affect the liver or interact with Foundayo
• Drink enough fluids if you have vomiting or diarrhoea, as dehydration puts extra strain on the body
• Seek prompt medical advice for yellowing of the skin or eyes, dark urine, pale stools, persistent upper stomach pain or unexplained itching

Is a Liver Blood Test Needed Before Starting?

The current UK product information does not specify routine liver-function testing for every patient before starting Foundayo. Your prescriber may nevertheless request liver tests if you have known liver disease, previous abnormal results or other clinical reasons.

Talking to a Prescriber About Your Liver Health

The evidence so far is reassuring, but it describes large groups, not individuals. If you have any liver condition, abnormal results in the past, or specific concerns, an assessment before starting is the right step.

EverydayMeds offers an online consultation with UK-registered prescribers, who will review your medical history, other medicines and any liver-related concerns before deciding whether Foundayo or another option is suitable.