According to research reviewed by Gram, the experimental drug miricorilant (CORT118335) appeared to lower liver fat in male mice within several days of daily dosing, and the effect reversed about 7 days after stopping. These laboratory findings support further study for fatty liver disease, but human results are not yet known.
Fatty liver disease, now called MASLD, affects many adults, and scientists are testing new drugs to treat it. A new laboratory study published in the European Journal of Pharmacology looked closely at miricorilant (CORT118335), an experimental drug that acts on a hormone receptor involved in metabolism. In male mice fed a high-fat diet, daily doses appeared to reduce liver fat within several days, and the effect faded after treatment stopped. The researchers also found that the drug’s breakdown products were unlikely to explain its benefits, and it did not work better when combined with two other fat-lowering drugs. According to research reviewed by Gram, these findings support further study of this approach, but the work was done in mice and cells, so results in people are not yet known.
Key Statistics
A 2026 preclinical study published in the European Journal of Pharmacology found that daily doses of the experimental drug miricorilant (CORT118335) appeared to lower liver fat in male mice within several days of treatment.
In the same mouse research, the liver-fat-lowering effect of miricorilant reversed after 7 days without treatment, suggesting continuous dosing may be needed to maintain the benefit.
A 2026 cell and mouse study reported that at a dose of 6 mg per kg per day, miricorilant produced clear changes in liver gene activity alongside a modest drop in liver fat.
The Quick Take
- What they studied: Scientists wanted to understand how an experimental drug called miricorilant lowers fat in the liver, which parts of the drug’s activity matter most, and whether it works well alongside other fat-lowering medicines.
- Who participated: The main experiments used laboratory mice fed a high-fat diet for a short time, and the most consistent liver-fat effects were seen in male mice. Some work was also done on cells grown in the lab. The exact number of animals was not specified in the study summary.
- Key finding: Daily doses appeared to lower liver fat within several days in male mice, and the effect reversed about 7 days after treatment stopped. A dose of 6 mg per kg per day produced clear changes in liver gene activity with a modest drop in liver fat, while higher doses cut liver fat more but produced less ongoing gene activity.
- What it means for you: This is early laboratory research, not proof that the drug works in people. It suggests that targeting this hormone receptor may be a possible way to reduce liver fat, but people with fatty liver disease should not try to get this drug outside of a clinical trial and should talk with their doctor about proven steps such as weight loss, healthy eating, and regular activity.
The Research Details
The researchers used several types of experiments. First, they tested the drug and its two main breakdown products in cells grown in the lab. They measured how strongly each version activated the glucocorticoid receptor, a protein that responds to stress-related hormones and helps control metabolism. One breakdown product was active, while the other was mostly inactive.
Next, they gave the drug to mice that were fed a high-fat diet for a short period. This allowed them to track how quickly liver fat changed after treatment started, and how quickly it returned after treatment stopped. They also tested whether the drug worked better when combined with two other medicines, a thyroid-related drug called VK2809 and a diabetes drug called pioglitazone. They also examined which genes in the liver were switched on or off at different doses.
Because the study used animals and cells rather than people, it could answer detailed questions about how the drug works inside the body. However, mice are not identical to humans, and short experiments cannot show long-term safety or benefit.
Testing in cells shows what a drug does at the molecular level, which helps explain why it works. Testing in animals shows whether those effects happen in a living body. Together, these steps help scientists decide whether a drug is worth testing in people and what doses might be reasonable to study. Looking at both the drug and its breakdown products also shows whether those byproducts contribute to the results.
The study was published in a peer-reviewed scientific journal, which means other experts reviewed it before publication. It used multiple types of experiments that support one another. However, the study summary does not state the number of animals used, and the mouse experiments were short and limited to a high-fat diet model. Results in one sex, male mice, may not apply to females or to people. Findings from animal and cell research often do not carry over to humans.
What the Results Show
The drug’s effects depended on which version of it was present. One of its breakdown products, called CORT118335-P9a, strongly activated the glucocorticoid receptor in cell tests. The other, CORT118335-P9b, was largely inactive. However, the active breakdown product was present at very low levels in the mouse liver, so the researchers concluded it is unlikely to be the main reason the drug works in living animals.
In the mouse experiments, daily treatment appeared to lower liver fat within several days, and this was seen mainly in male mice. When treatment was stopped, the benefit faded, with the effect reversing after 7 days. This suggests that the drug must be taken continuously to keep liver fat lower, which is consistent with how many medicines work.
The drug also showed a complex pattern at different doses. At 6 mg per kg per day, it changed the activity of many genes involved in fat processing in the liver and produced a modest drop in liver fat. Higher doses lowered liver fat more strongly, but these higher doses did not keep gene activity as active. This means that the amount of liver fat lowered and the biological changes behind it do not always move together.
The researchers also found no added benefit when miricorilant was combined with VK2809 or pioglitazone. In other words, the drugs did not appear to work better together than alone in these mouse tests.
The study showed that the drug’s gene effects and its fat-lowering effects can be separated. This is useful information for drug developers because it suggests that the best dose for lowering liver fat may not be the same as the dose that produces the strongest gene changes. The findings also show that combining this drug with certain other fat-lowering medicines did not produce extra benefit in these experiments, which may help guide which combinations are tested in future clinical trials.
The researchers note that miricorilant had already shown strong effects on liver health in earlier mouse studies and was moving into human clinical trials for fatty liver disease. This new study adds detail about how the drug works, which breakdown products matter, and how its effects change with dose. It builds on the broader idea that selective glucocorticoid receptor modulators, which target one part of a hormone system, may offer a way to treat metabolic conditions without the full range of side effects linked to traditional steroid hormones.
The study was done in mice and cells, so its results may not match what happens in people. Mice were fed a high-fat diet for a short time, which does not fully represent the long-term course of fatty liver disease in humans. The main liver-fat effects were seen in male mice, so the findings may not apply equally to females. The study summary also does not state how many animals were used, which makes it harder to judge how strong the evidence is. Finally, the research focused on how the drug works rather than on long-term safety, so it does not answer questions about side effects over months or years.
The Bottom Line
Based on this laboratory research, scientists have reasonable evidence that miricorilant acts on liver fat in mice through a specific hormone receptor. Confidence that the same effect will happen in people is low at this stage, because the work has not yet been tested in human trials in this report. People with fatty liver disease should continue to follow proven, doctor-guided approaches such as weight management, limiting sugar and refined carbohydrates, regular physical activity, and medical follow-up.
Researchers, drug developers, and clinicians who follow fatty liver disease treatments should pay close attention because the study helps explain how this drug works. People living with fatty liver disease may find the work encouraging, but they should not take experimental drugs without medical supervision. Anyone who is not dealing with liver fat or metabolic disease has little need to act on these findings.
Lab results like these usually take years to reach patients. The drug would need to be tested in people for safety and effectiveness, and those trials take time to complete. Even if the drug later proves helpful, changes in liver fat would likely be measured over weeks to months in a medical setting, not days at home.
Frequently Asked Questions
Can miricorilant help lower liver fat in people with fatty liver disease?
Miricorilant has shown liver fat-lowering effects in mouse studies, but it has not been proven in people through this research alone. It is being evaluated in clinical trials for MASLD, so its safety and benefit in humans remain under investigation.
How long does miricorilant take to reduce liver fat in mice?
In a 2026 European Journal of Pharmacology study, daily miricorilant appeared to lower liver fat in male mice within several days. The benefit reversed about 7 days after treatment stopped, suggesting continuous use is needed to maintain it.
What is MASLD and how is it different from fatty liver disease?
MASLD stands for metabolic dysfunction-associated steatotic liver disease, a newer name for fatty liver disease linked to metabolic problems such as excess weight or insulin resistance. It involves fat building up in the liver and is treated mainly through weight management, diet, and physical activity.
Does combining miricorilant with other fat-lowering drugs work better?
In this mouse study, combining miricorilant with the thyroid-related drug VK2809 or the diabetes drug pioglitazone did not produce extra liver fat reduction beyond what each drug achieved alone. Human results may differ, and combination treatment decisions should be made with a doctor.
Want to Apply This Research?
- Track daily body weight, waist measurement, and minutes of physical activity, and log these alongside any liver health test results your doctor shares with you, such as liver enzyme or liver fat scan results. Users with a diagnosis can record their weekly servings of sugary drinks and high-fat processed foods as well.
- Use the app to set one realistic habit goal each week, such as walking 20 minutes after dinner five days a week or replacing one sugary drink per day with water. Share progress with your healthcare provider so they can help you decide what is working.
- Review trends monthly rather than daily, focusing on whether weight, waist size, and activity are moving in a healthy direction over several months. Keep a running record of any medicines you take, including experimental treatments in a clinical trial, so your doctor can review them together. Update the app if your doctor changes your plan.
This article summarizes a laboratory study conducted in mice and cells and is not medical advice. The drug discussed is experimental and has not been approved for treating fatty liver disease. Do not change any medication or treatment plan based on this research. Talk with your doctor or a liver specialist about proven options for managing fat in your liver.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.