Resmetirom

Pronunciation: res-me-TIR-om
Generic name: resmetirom
Brand name: Rezdiffra
Dosage form: oral tablets (60mg, 80mg, 100mg)
Drug class: Miscellaneous metabolic agents

Medically reviewed by Carmen Pope, BPharm. Last updated on Mar 18, 2025.

What is Resmetirom?

Resmetirom is used to treat nonalcoholic steatohepatitis (NASH) in adults with moderate to advanced liver scarring (fibrosis) but not with cirrhosis of the liver. It is a tablet taken once daily that is used along with diet and exercise. The brand name is Rezdiffra.

Resmetirom gained FDA approval on March 14, 2024, under the brand Rezdiffra made by Madrigal Pharmaceuticals. There is no generic.

• This approval was under the accelerated approval designation which means continued approval may be contingent on a clinical benefit being shown in confirmatory trials. 

Mechanism

Resmetirom works by attaching to the THR-beta (thyroid hormone receptor-beta) receptor in the liver. When activated, this receptor helps reduce fat buildup in your liver.

• Excess liver fat, including triglycerides, can lead to NASH and liver problems such as swelling, scarring (fibrosis), and severe damage (cirrhosis).
• By partially activating the THR-beta receptor, resmetirom helps lower liver triglycerides and lipoprotein cholesterol (LDL-C).

Resmetirom belongs to the drug class called THR-beta agonists. 

How effective is resmetirom?

Clinical trials report significantly better outcomes with resmetirom compared to placebo (an inactive treatment).

• 2 to 3 times more patients taking resmetirom compared to placebo showed NASH symptom improvement in a large clinical trial of 966 adults.
• 1.5 to 2 times more patients than placebo reported reduced liver scarring.
• Resmetirom significantly reduced LDL-C and triglyceride levels. 

Side effects

The most common side effects of resmetirom are:

• diarrhea or constipation
• itching
• nausea or vomiting
• stomach (abdominal) pain
• dizziness.

Serious side effects and warnings

Resmetirom may cause the following serious side effects:

• Liver injury (hepatotoxicity). Resmetirom may cause damage to your liver. Stop taking it and call your healthcare provider right away if you develop:
  • tiredness
  • fever
  • pain or tenderness in the upper middle or upper right area of your stomach (abdomen)
  • nausea or vomiting
  • rash
  • your skin or the white part of your eyes turns yellow (jaundice).
• Gallbladder problems. Problems such as gallstones, inflammation of the gallbladder, or inflammation of the pancreas from gallstones can occur because of NASH or resmetirom. Call your healthcare provider right away if you develop nausea, vomiting, fever, or pain in your stomach area (abdomen) that is severe and will not go away. The pain may be felt going from your abdomen to your back and the pain may happen with or without vomiting.

It is not known if resmetirom is safe and effective in children under the age of 18.

These are not all the possible side effects of resmetirom. For more information, ask your healthcare provider or pharmacist. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects to www.fda.gov/medwatch.

Related/similar drugs

Before taking

Before you take resmetirom, tell your healthcare provider about all of your medical conditions, including if you:

• have any liver problems other than NASH
• have gallbladder problems or have been told you have gallbladder problems, including gallstones
• are taking other medications such as gemfibrozil to lower your cholesterol or cyclosporine to suppress your immune system, because some of these may not be recommended
• are pregnant or plan to become pregnant
• are breastfeeding or plan to breastfeed.

Pregnancy

It is not known if resmetirom will harm your unborn baby. Talk to your healthcare provider about the risk to the baby from resmetirom if you become pregnant. Report pregnancies to Madrigal Pharmaceuticals, Adverse Event reporting line at 1-800-905-0324 and https://www.madrigalpharma.com/contact/

Breastfeeding

It is not known if resmetirom passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby while you are taking it.

How do I take resmetirom?

Take resmetirom exactly as your healthcare provider tells you to take it.

• Resmetirom is a tablet taken 1 time a day by mouth.
• May be taken with or without food.
• The dosage depends on your weight.

Dosing information

Your resmetirom dose is based on your body weight. Your healthcare provider will calculate this for you and it may depend on what other medications you take. The recommended dosage is:

• Body weight less than 100kg: 80mg once daily
• Body weight of 100kg or more: 100mg once daily.

What other drugs will affect resmetirom?

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

Especially tell your healthcare provider if you take medicines such as:

• Strong CYP2C8 inhibitors, such as gemfibrozil (concomitant use not recommended)
• Moderate CYP2C8 inhibitors, such as clopidogrel (reduce dosage)
• OATP1B1 and OATP1B3 inhibitors, such as cyclosporine (concomitant use not recommended)
• Statins, such as atorvastatin, fluvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin and simvastatin (limit the statin dosage)
• CYP2C8 substrates, such as loperamide, montelukast, or paclitaxel (may increase the risk of side effects).

This is not a complete list of interactions. Know the medicines you take. Keep a list of them to show your healthcare provider and pharmacist when you get a new medicine.

Storage

Store at room temperature between 68ºF to 77ºF (20ºC to 25ºC).

Ingredients

Active ingredient: resmetirom.

Inactive ingredients: colloidal silicon dioxide, croscarmellose sodium, magnesium stearate, mannitol, and microcrystalline cellulose.

Film coating: polyethylene glycol, polyvinyl alcohol, talc, titanium dioxide, red iron oxide (100 mg tablets), and yellow iron oxide (80 mg and 100 mg tablets).

Manufacturer

Resmetirom is manufactured by Madrigal Pharmaceuticals, which is headquartered in Conshohocken, Pennsylvania (a suburb of Philadelphia) under the brand name Rezdiffra.

Madrigal is a relatively small pharmaceutical company that has largely focused on developing treatments for liver diseases. Resmetirom (Rezdiffra) is their first FDA-approved medication.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer