Fatty liver disease (MASLD/MASH) and weight: the new names, who is at risk, FIB-4 testing, how much weight loss helps, and the two FDA-approved MASH medicines.
Fact-checked against FDA labels and official sources; not yet reviewed by a licensed clinician. This page is education, not medical advice. Talk to your doctor before starting, stopping or changing any treatment.
Key facts
- Who to ask
- Bariatric surgery, Obesity medicine, Primary care, Registered dietitian
- Also called
- fatty liver, MASLD, MASH, NAFLD, NASH, metabolic dysfunction-associated steatotic liver disease, fatty liver weight loss
Key takeaways
- MASLD replaced the name NAFLD in 2023; MASH replaced NASH.[2]
- Losing 3% to 5% of body weight improves liver fat; more than 10% is generally required to improve MASH and fibrosis.[1]
- Among people with NASH who lost 10% or more of their weight, 90% saw NASH resolve and 45% had fibrosis regression.[11]
- Rezdiffra (March 14, 2024) and Wegovy injection (August 15, 2025) have FDA accelerated approval for noncirrhotic MASH with F2 to F3 fibrosis.[8]
- Cardiovascular disease is the leading cause of death in people with fatty liver disease.[1]
In short: Fatty liver disease linked to metabolic health, now called MASLD (metabolic dysfunction-associated steatotic liver disease), affects an estimated 25% to 30% of adults. Its more serious form, MASH, involves inflammation and can scar the liver. Weight loss is the core treatment: in one study, 90% of people with MASH who lost 10% or more of their weight saw it resolve. As of October 6, 2026 the FDA has approved two medicines for MASH with moderate to advanced scarring, both under accelerated approval: Rezdiffra (resmetirom, March 2024) and Wegovy (semaglutide, August 2025). Because MASLD usually has no symptoms, testing and follow-up with a clinician are essential.
This page is general education about fatty liver disease and weight. It cannot tell you whether you have liver disease or how advanced it is. Please talk with a licensed clinician, get the right tests, and do not start supplements or “liver detox” products, which can harm the liver.
Fatty liver disease at a glance
- 25-30%of adults are estimated to have fatty liver disease (NAFLD/MASLD)AASLD Practice Guidance 2023
- About 6%of U.S. adults (14.9 million) have MASH, the inflammatory formU.S. Food and Drug Administration
- Over 90%of people with severe obesity have fatty liver diseaseNIDDK
- 1/3 to 2/3of people with type 2 diabetes have fatty liver diseaseNIDDK
Checked on October 6, 2026
What MASLD and MASH mean (and the old names)
In 2023 a group of liver societies from around the world agreed on new names after a consensus process involving 236 experts from 56 countries. The old terms, nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH), were dropped partly because the words “nonalcoholic” and “fatty” were seen as stigmatizing. The new terms are:
- MASLD (metabolic dysfunction-associated steatotic liver disease): fat in the liver plus at least one of five cardiometabolic risk factors, such as excess weight around the waist, high blood sugar, high blood pressure or abnormal blood fats. It replaces NAFLD.
- MASH (metabolic dysfunction-associated steatohepatitis): MASLD with inflammation and liver cell injury, which can lead to scarring (fibrosis). It replaces NASH.
- MetALD: MASLD in people who also drink more alcohol, defined as 140 to 350 grams a week for women and 210 to 420 grams a week for men. One U.S. standard drink contains about 14 grams of alcohol, so that is roughly 10 to 25 drinks a week for women and 15 to 30 for men.
You will still see the old names on older web pages and some medical records. The NIDDK notes that NAFLD is also referred to as MASLD and NASH as MASH.
Who is more likely to have it
The NIDDK reports that fatty liver disease affects about 24% of U.S. adults and nearly 10% of children aged 2 to 19, one third to two thirds of people with type 2 diabetes, up to 75% of people with overweight and more than 90% of people with severe obesity. It is most common among Hispanic people, followed by non-Hispanic white and Asian American people, and less common among non-Hispanic Black people. Because it is so closely tied to insulin resistance and type 2 diabetes, many people have more than one of these conditions.
Why it matters: from fat to scarring
Most people with MASLD have fat in the liver without much inflammation. In some, MASH develops, and over years the inflammation can cause fibrosis. The NIDDK explains that MASH can progress to cirrhosis (severe scarring) and liver cancer, and that cirrhosis may eventually require a liver transplant. Doctors grade fibrosis in stages; the approved MASH medicines are for “moderate to advanced” fibrosis, described on the Wegovy label as consistent with stages F2 to F3, and the AASLD treats stage 2 or higher as clinically significant.
Heart health matters just as much. According to the American Association for the Study of Liver Diseases (AASLD) 2023 guidance, cardiovascular disease is the leading cause of death in people with fatty liver disease, followed by liver disease. That is why care for MASLD always includes blood pressure, cholesterol and blood sugar. The AASLD says statins are safe in people with fatty liver disease across the spectrum, including advanced liver disease.
Tests a clinician may order
The NIDDK calls fatty liver disease a silent disease with few or no symptoms, even when cirrhosis develops; when symptoms occur they can include fatigue and discomfort in the upper right belly. It is usually found through tests. The AASLD also notes that the “normal” liver enzyme range on many lab reports is higher than what should be considered normal in fatty liver disease. The AASLD advises targeted screening of people at higher risk of advanced liver disease, including people with type 2 diabetes, obesity with metabolic complications, a family history of cirrhosis, or significant alcohol use. The usual first step is a simple score called FIB-4, calculated from age, two liver enzymes (ALT and AST) and the platelet count:
How the AASLD guidance uses the FIB-4 score
- FIB-4 under 1.3Low risk: managed in primary care, rechecked every 2 to 3 years (1 to 2 years with diabetes or 2+ metabolic risk factors).
- FIB-4 1.3 to 2.67Intermediate: a second test such as a liver stiffness scan (VCTE) or the ELF blood test.
- FIB-4 over 2.67High risk: referral to a gastroenterologist or hepatologist.
- Specialist workupMay include imaging, more blood tests and, in some cases, a liver biopsy.
Only your clinician can interpret these results together with your history. Ask for your FIB-4 number and what it means.
Weight loss: the core treatment
The AASLD guidance says losing 3% to 5% of body weight improves liver fat, while more than 10% is generally required to improve MASH and fibrosis. The NIDDK makes the same first point: losing at least 3% to 5% of body weight may reduce fat in the liver. A study of 293 people with biopsy-proven NASH, published in Gastroenterology in 2015, shows how strongly results depend on the amount of weight lost through lifestyle change over 52 weeks:
| Item | Steatohepatitis resolved | Fibrosis regressed |
|---|---|---|
| Whole group | 25% | 19% |
| Lost 10% or more | 90% | 45% |
293 adults with biopsy-proven NASH. In the same study, 58% of people who lost at least 5% saw NASH resolve. Observational analysis within one cohort.
Source: Vilar-Gomez E et al., Gastroenterology 2015 (checked on October 6, 2026)
In the whole group, 25% saw steatohepatitis resolve and 19% had fibrosis regression. Among people who lost 10% or more, 90% saw NASH resolve and 45% had fibrosis regression. The authors concluded that greater weight loss is linked to greater improvement. For many people, 10% is a big goal; the good news is that smaller losses still reduce liver fat, and any loss is worth protecting.
What else the AASLD guidance recommends
- Diet: a Mediterranean diet is often recommended because of its heart and liver benefits. Our nutrition hub has the basics.
- Coffee: drinking 3 or more cups a day could be recommended, based on a lower risk of fibrosis.
- Exercise: aim for about 150 minutes a week of moderate-intensity activity, done regularly. Our walking plan is an easy way to build up.
- Alcohol: avoid heavy drinking (60 grams a day or more for men, 40 grams or more for women). The guidance also notes that heavy drinking speeds up liver injury and that even moderate drinking raises the chance of advanced fibrosis, particularly with obesity or type 2 diabetes; ask what is safe for you.
FDA-approved medicines for MASH
For years there was no approved medicine. As of October 6, 2026, the FDA has approved two, both for adults with noncirrhotic MASH and moderate to advanced fibrosis (stages F2 to F3), both alongside diet and exercise, and both under the accelerated approval pathway. Accelerated approval is used for serious conditions with unmet needs; continued approval may depend on confirmatory trials showing clinical benefit, such as the 54-month outcomes trial the FDA requires for Rezdiffra.
Rezdiffra (resmetirom)
The FDA approved Rezdiffra on March 14, 2024, as the first treatment for MASH with liver scarring. It is a daily tablet whose dose is based on body weight. The label says to avoid it in people with decompensated cirrhosis, warns about drug-induced liver injury and gallbladder problems, and lists interactions: strong CYP2C8 inhibitors such as gemfibrozil should not be used with it, and some statin doses must be limited. Diarrhea and nausea were the most common side effects. The manufacturer must complete a 54-month outcomes trial.
| Item | Placebo | 80 mg | 100 mg |
|---|---|---|---|
| MASH resolved, no fibrosis worsening | 13% | 27% | 36% |
| Fibrosis improved, no MASH worsening | 15% | 23% | 28% |
888 adults with F2 or F3 fibrosis. Pathologist A readings shown; a second pathologist read 9/26/24% and 13/23/24%.
Source: REZDIFFRA prescribing information, section 14 (DailyMed) (checked on October 6, 2026)
Wegovy (semaglutide)
Wegovy injection received accelerated approval for noncirrhotic MASH with moderate to advanced fibrosis (F2 to F3) in adults on August 15, 2025, according to Drugs@FDA; the FDA announced it shortly after. It is the first GLP-1 medicine with this indication. The MASH indication applies to the injection; Wegovy tablets are not approved for MASH. The evidence comes from the ESSENCE trial, published in the New England Journal of Medicine in 2025, which enrolled 800 people with biopsy-confirmed MASH and F2 or F3 fibrosis:
| Item | Semaglutide | Placebo |
|---|---|---|
| Steatohepatitis resolved, no fibrosis worsening | 62.9% | 34.3% |
| Fibrosis reduced, no steatohepatitis worsening | 36.8% | 22.4% |
| Both | 32.7% | 16.1% |
| Body weight lost | 10.5% | 2% |
800 adults with MASH and F2 or F3 fibrosis (534 semaglutide, 266 placebo in this analysis).
Source: Sanyal AJ et al., NEJM 2025 (ESSENCE) (checked on October 6, 2026)
Wegovy carries a boxed warning about thyroid C-cell tumors seen in rodents and is not used by people with a personal or family history of medullary thyroid carcinoma or MEN 2. Its other warnings, common side effects and costs are on our Wegovy page and in GLP-1 side effects.
Medicines used off-label
The AASLD 2023 guidance also discusses pioglitazone (a diabetes medicine) and vitamin E. Neither is FDA approved for MASH. The guidance says pioglitazone improves NASH resolution, and it reserves vitamin E for people with NASH who do not have type 2 diabetes or cirrhosis, because of a possible risk of hemorrhagic stroke. These are decisions for a liver specialist; do not start high-dose vitamin E on your own.
Bariatric surgery and fatty liver
For people who meet surgical criteria, metabolic and bariatric surgery produces large, lasting weight loss, which is the main driver of liver improvement. The 2022 ASMBS and IFSO guidelines recommend surgery for a BMI over 35 and say it should be considered from a BMI of 30 with metabolic disease. Read our bariatric surgery guide.
Cost and insurance
FIB-4 uses routine blood tests; liver stiffness scans and specialist visits are billed separately, so ask your plan. For Medicare, CMS says beneficiaries with noncirrhotic MASH with advanced fibrosis are not eligible for the temporary GLP-1 Bridge and use their regular Part D plan instead (checked 2026-10-06). Wegovy self-pay through NovoCare Pharmacy was $349 a month for the regular pens on the same date. We did not find an official current price for Rezdiffra to publish; ask your pharmacy or the manufacturer’s support program. Our Wegovy cost page and insurance hub have more.
When to see a doctor
Ask about liver testing if you have type 2 diabetes, obesity with other metabolic problems, a family history of cirrhosis or heavy alcohol use, or if a scan or blood test has shown fat in your liver or raised liver enzymes. Because the disease can be silent even when advanced, regular follow-up matters more than waiting for symptoms. A primary care clinician can start with FIB-4 and refer you to a gastroenterologist or hepatologist if needed. The conditions hub links to related conditions.
Overview
MASLD (formerly NAFLD) is fat in the liver plus at least one cardiometabolic risk factor; MASH (formerly NASH) adds inflammation and can lead to fibrosis, cirrhosis and liver cancer. It affects an estimated 25% to 30% of adults and over 90% of people with severe obesity. Weight loss of 3% to 5% improves liver fat and more than 10% is generally needed to improve MASH and fibrosis. Two medicines have FDA accelerated approval for noncirrhotic MASH with F2-F3 fibrosis: Rezdiffra (2024) and Wegovy injection (2025).
Signs
- Usually few or no symptoms, even with cirrhosis (NIDDK)
- When present: fatigue, discomfort in the upper right belly
Tests a clinician may order
- Liver blood tests and platelet count, used to calculate the FIB-4 score
- Liver stiffness scan (vibration-controlled transient elastography) or ELF blood test if FIB-4 is 1.3 to 2.67
- Ultrasound or other imaging
- Liver biopsy in selected cases
- Blood sugar, blood pressure and cholesterol
What lifestyle research shows
AASLD 2023: 3-5% weight loss improves steatosis; more than 10% is generally required to improve NASH and fibrosis; Mediterranean diet often recommended; 3+ cups of coffee a day could be recommended; about 150 minutes a week of moderate activity; avoid heavy alcohol. Vilar-Gomez 2015 (293 adults with NASH): with 10% or more weight loss, 90% had NASH resolution and 45% fibrosis regression at 52 weeks.
When to see a doctor
Ask about testing if you have type 2 diabetes, obesity with metabolic problems, a family history of cirrhosis, heavy alcohol use, or a scan or blood test showing liver fat or raised enzymes. Keep up regular follow-up, because the disease can be silent even when advanced.
Treatments discussed
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Tools for this topic
Questions to ask your doctor or pharmacist
- What is my FIB-4 score, and do I need a liver stiffness scan or a specialist referral?
- Do I have MASLD, MASH or MetALD, and what stage of fibrosis?
- How much weight loss would help my liver, and what support can you offer?
- Would Rezdiffra or Wegovy be appropriate for me, and what monitoring would I need?
- Are any of my medicines or supplements a concern for my liver?
- How should we manage my heart risk, including blood pressure and cholesterol?
Frequently asked questions
Can fatty liver disease be reversed?
Liver fat often improves with weight loss, and MASH and even some fibrosis can improve, especially with larger weight loss. In one study, 90% of people with NASH who lost 10% or more of their weight saw NASH resolve. Your liver team can tell you what is realistic for your stage.
How much weight do I need to lose for my liver?
The AASLD says 3% to 5% improves liver fat and more than 10% is generally required to improve MASH and fibrosis. For a 200-pound person, that is 6 to 10 pounds and more than 20 pounds.
What is the difference between MASLD and MASH?
MASLD is fat in the liver with at least one metabolic risk factor. MASH is MASLD with inflammation and liver cell injury, which can lead to scarring. MASH needs closer follow-up.
Is there a medicine for fatty liver?
For MASH with moderate to advanced scarring (F2 to F3) and no cirrhosis, the FDA has approved Rezdiffra (resmetirom) and Wegovy injection (semaglutide), both under accelerated approval, as of October 6, 2026. There is no approved medicine for simple liver fat without MASH.
Is Wegovy approved for fatty liver?
Wegovy injection is approved for noncirrhotic MASH with moderate to advanced fibrosis (F2 to F3) in adults, under accelerated approval since August 2025. Wegovy tablets are not approved for MASH.
Is coffee good for fatty liver?
The AASLD guidance says drinking 3 or more cups of coffee a day could be recommended, based on a lower risk of fibrosis. It is not a treatment on its own; check with your clinician if you have heart rhythm or sleep problems.
Can I drink alcohol with fatty liver disease?
The AASLD advises avoiding heavy drinking (60 grams a day or more for men, 40 grams for women; one U.S. standard drink is about 14 grams) and notes that even moderate drinking raises the chance of advanced fibrosis, particularly with obesity or type 2 diabetes. Ask what is safe for you.
What is a FIB-4 score?
A score calculated from age, the liver enzymes ALT and AST, and the platelet count that estimates the chance of advanced scarring. Under 1.3 is low risk, 1.3 to 2.67 needs a second test, and over 2.67 usually means referral to a liver specialist, according to the AASLD.
Does fatty liver cause symptoms?
Usually few or none. The NIDDK calls it a silent disease, even when cirrhosis develops; some people notice fatigue or discomfort in the upper right belly. That is why testing people at higher risk matters.
References
- Rinella ME, Neuschwander-Tetri BA, Siddiqui MS, et al.. AASLD Practice Guidance on the clinical assessment and management of nonalcoholic fatty liver disease. Hepatology, 2023. doi:10.1097/HEP.0000000000000323 · PMID 36727674 (accessed October 6, 2026) Guideline
- Rinella ME, Lazarus JV, Ratziu V, et al.. A multisociety Delphi consensus statement on new fatty liver disease nomenclature. Journal of Hepatology, 2023. doi:10.1016/j.jhep.2023.06.003 · PMID 37364790 (accessed October 6, 2026) Guideline
- Definition and Facts of NAFLD and NASH. National Institute of Diabetes and Digestive and Kidney Diseases (NIH). (accessed October 6, 2026) Government page
- Health Risks of Overweight and Obesity. National Institute of Diabetes and Digestive and Kidney Diseases (NIH). (accessed October 6, 2026) Government page
- FDA approves treatment for serious liver disease known as MASH (Wegovy). U.S. Food and Drug Administration (email bulletin), 2025. (accessed October 6, 2026) Government page
- Drugs@FDA: Wegovy, NDA 215256, approval history. U.S. Food and Drug Administration. (accessed October 7, 2026) Government page
- WEGOVY (semaglutide) injection and tablets: prescribing information. Novo Nordisk, via DailyMed, 2026. (accessed October 7, 2026) Drug label
- FDA Approves First Treatment for Patients with Liver Scarring Due to Fatty Liver Disease. U.S. Food and Drug Administration, 2024. (accessed October 6, 2026) Government page
- REZDIFFRA (resmetirom) tablets: prescribing information (revised July 2026). Madrigal Pharmaceuticals, via DailyMed. (accessed October 6, 2026) Drug label
- Sanyal AJ, Newsome PN, Kliers I, et al.. Phase 3 Trial of Semaglutide in Metabolic Dysfunction-Associated Steatohepatitis (ESSENCE). New England Journal of Medicine, 2025. doi:10.1056/NEJMoa2413258 · PMID 40305708 · NCT04822181 (accessed October 6, 2026) Randomized trial
- Vilar-Gomez E, Martinez-Perez Y, Calzadilla-Bertot L, et al.. Weight Loss Through Lifestyle Modification Significantly Reduces Features of Nonalcoholic Steatohepatitis. Gastroenterology, 2015. doi:10.1053/j.gastro.2015.04.005 · PMID 25865049 (accessed October 6, 2026) Other
- What Is A Standard Drink?. National Institute on Alcohol Abuse and Alcoholism (NIH). (accessed October 6, 2026) Government page
- Eisenberg D, Shikora SA, Aarts E, et al.. 2022 ASMBS and IFSO: Indications for Metabolic and Bariatric Surgery. Surgery for Obesity and Related Diseases, 2022. doi:10.1016/j.soard.2022.08.013 · PMID 36280539 (accessed October 6, 2026) Guideline
- Medicare GLP-1 Bridge: Information for Part D Plans. Centers for Medicare & Medicaid Services. (accessed October 6, 2026) Government page
- Wegovy at NovoCare Pharmacy: self-pay prices. Novo Nordisk (NovoCare Pharmacy). (accessed October 7, 2026) Other
Facts checked on October 6, 2026
Educational information, not medical advice. Talk with a qualified healthcare professional about your own situation. In an emergency call 911.