Understanding the New Terminology: NAFLD Is Now MASLD, NASH Is Now MASH

Before searching for a study, it helps to know that the medical community recently updated the names for these liver conditions. In June 2023, a multisociety Delphi consensus led by the American Association for the Study of Liver Diseases (AASLD), the European Association for the Study of the Liver (EASL), and the Latin American Association for the Study of the Liver (ALEH) formally replaced NAFLD with metabolic dysfunction–associated steatotic liver disease (MASLD) and NASH with metabolic dysfunction–associated steatohepatitis (MASH). The change was made to remove stigmatizing language and to better reflect the metabolic origins of the disease.

MASLD is defined as hepatic steatosis (liver fat) in the presence of at least one cardiometabolic risk factor — such as obesity, insulin resistance, hypertension, or dyslipidemia — without significant alcohol consumption. A new sub-category called MetALD captures patients who meet MASLD criteria but drink above the traditional alcohol limits.

Importantly, these name changes do not alter clinical trial design, disease staging, or biomarker definitions. Research published under the NAFLD/NASH nomenclature remains fully applicable, and the overlap between populations defined by the old and new criteria is greater than 99 percent. When searching trial databases you will still find studies listed under both NAFLD/NASH and MASLD/MASH headings, so use all four terms in your searches.

Why People Join Fatty Liver Disease Studies

• Early access to investigational therapies — Many promising drugs are only available inside clinical trials.
• Expert monitoring at no cost — Participants typically receive laboratory tests, imaging, and specialist consultations covered by the study sponsor.
• Contributing to science — NAFLD is the most common liver disease in adults and the second-leading cause for liver transplantation in the United States. Better treatments are urgently needed.
• Compensation — Many studies reimburse travel costs and provide stipends for time spent at clinic visits.

Step 1 — Find Studies Recruiting Near You

Several resources allow you to search for NASH/NAFLD (MASH/MASLD) clinical trials by zip code or city:

1. ClinicalTrials.gov — The largest trial registry in the world. Search “NASH,” “NAFLD,” “MASLD,” or “MASH” and filter by “Recruiting” status and your location.
2. University medical center portals — Academic sites such as UCSD, UCSF, and UC Davis maintain dedicated liver-disease trial listings that are updated regularly.
3. Clinical research organizations (CROs) — Companies like EBG Clinical Research (ebgcr.com) connect patients with actively enrolling studies across multiple therapeutic areas, including liver disease. Visiting their website or calling their recruitment line is one of the fastest ways to find out what is open near you.
4. Your gastroenterologist or hepatologist — Your doctor may already have referral relationships with local research sites.
5. Patient advocacy groups — The Global Liver Institute and the American Liver Foundation both maintain trial-finder tools and educational resources.

Step 2 — Review Eligibility Criteria

Every clinical study has a unique set of inclusion and exclusion criteria. While specifics vary, common requirements for NASH/MASH trials include:

Typical Inclusion Criteria

• Age 18 or older (some pediatric studies exist for adolescents)
• Confirmed or suspected NASH/MASH, often by liver biopsy showing steatosis, lobular inflammation, and hepatocyte ballooning
• Presence of liver fibrosis at a specific stage (e.g., stage F1b through F3 for non-cirrhotic studies, or compensated cirrhosis for other trials)
• At least one cardiometabolic risk factor such as obesity, type 2 diabetes, hypertension, or dyslipidemia
• Stable body weight in the months preceding enrollment

Common Exclusion Criteria

• Other chronic liver diseases (e.g., hepatitis B or C, autoimmune hepatitis)
• Decompensated cirrhosis
• Excessive alcohol consumption above defined thresholds (typically >20 g/day for women, >30 g/day for men)
• Pregnancy, breastfeeding, or plans to become pregnant during the study
• Recent bariatric or intestinal surgery (often within the past five years)
• HbA1c above 9% in some metabolic-focused trials

If you are unsure whether you qualify, a research coordinator at the study site can conduct a pre-screening conversation — usually by phone — to determine your potential eligibility before any in-person visit.

Step 3 — Complete the Screening Process

Once you contact a research site and appear to be a potential fit, you will be invited for a formal screening visit. This visit typically includes:

• Medical history review — The study team will assess your full health background, current medications, and lifestyle factors.
• Blood work — Lab panels including liver enzymes (ALT, AST), metabolic markers, HbA1c, and lipid profiles.
• Imaging — FibroScan (vibration-controlled transient elastography) to measure liver stiffness and fat, or MRI-based proton density fat fraction (MRI-PDFF) for precise quantification of hepatic steatosis. Some studies also use a newer portable MR device called LiverScope.
• Liver biopsy — Many Phase 2 and Phase 3 NASH trials still require a biopsy to confirm diagnosis and fibrosis stage. This is currently the most generally accepted procedure for diagnosing NASH and accurately assessing fibrosis progression.
• Physical examination — Including BMI, blood pressure, and waist circumference.

The screening window may last from a few days to several weeks, depending on the protocol. Not everyone who screens will ultimately qualify — and that is completely normal.

Step 4 — Informed Consent & Enrollment

Before any study procedures begin, you will review and sign an informed consent form (ICF). This document explains:

• The purpose and design of the study
• All procedures you may undergo
• Potential risks and benefits
• Your right to withdraw at any time without penalty
• How your data and biological samples will be protected

Take as much time as you need. Ask questions. A good research team will encourage you to discuss the study with your family and personal physician before committing.

Step 5 — What to Expect During a Study

Study duration and visit frequency vary widely:

• Short studies (Phase 1/2) — May last 12 to 52 weeks with visits every two to four weeks. For example, some Phase 2 NASH studies involve clinic visits every four weeks for 52 weeks, plus a post-dosing end-of-study visit at week 56.
• Long-term outcome studies (Phase 3) — Can last up to five years. Certain large semaglutide and resmetirom trials involve up to 21 clinic visits and 9 phone calls over the study period, with some visits spread across multiple days.
• Observational registries — Studies like TARGET-NASH or the Liver Cirrhosis Network (LCN) Cohort Study track participants over time with visits every six months, including questionnaires, physical exams, imaging, and sample collection. Some components may be completed via telehealth.

During interventional trials, you may receive an active study drug or a placebo — and in most designs, neither you nor the research team knows which one you are receiving (this is called “double-blinding”). Treatment assignment is determined randomly to ensure unbiased results.

Active Therapies Being Studied in 2025–2026

The NASH/MASH clinical trial landscape is more active than ever. Here is a snapshot of notable drug classes and studies currently enrolling or reporting results:

New targets continue to emerge across de novo lipogenesis inhibitors, FXR agonists, and mitochondrial pyruvate carrier modulators. Joining a study now gives you the possibility of accessing tomorrow’s therapies today.

Key Takeaways

• NAFLD is now called MASLD and NASH is now called MASH — search for all four terms when looking for studies.
• MASLD/MASH affects more than 30 percent of the global population and is the most common chronic liver disease worldwide.
• Resmetirom (Rezdiffra) became the first FDA-approved medication specifically for MASH in March 2024 — but many more therapies are in active Phase 2 and Phase 3 trials.
• Eligibility usually requires confirmed liver fat and fibrosis, at least one metabolic risk factor, and the absence of other chronic liver diseases.
• Clinical research organizations like EBG Clinical Research (ebgcr.com) can help match you with enrolling studies quickly.
• Participation is voluntary, closely monitored, and you may withdraw at any time.

Frequently Asked Questions