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What is the mechanism of action for Juxtapid (lomitapide)?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on Feb 20, 2023.

Official answer


Juxtapid is an oral prescription medicine that works by decreasing the amount of “bad cholesterol” (low density lipoprotein or LDL) your liver produces. It is used in addition to a low-fat diet and other cholesterol-lowering treatments in people with homozygous familial hypercholesterolemia (HoFH), an inherited type of high cholesterol.

How does Juxtapid work?

Juxtapid binds directly to a protein in the cell called the microsomal triglyceride transfer protein (MTP). This helps to prevent the synthesis of chylomicrons and very low density lipoprotein (VLDL), which are triglyceride-rich lipoproteins.

Blocking the production of VLDL leads to reduced levels of LDL in patients with HoFH. This is important because in patients with HoFH, LDL-C levels may be over 400 mg/dL.

Juxtapid also works by lowering total cholesterol (TC), apolipoprotein B (a protein that carries “bad” cholesterol in the blood), and non-high-density lipoprotein cholesterol (non-HDL-C) in patients with HoFH.

What is Juxtapid?

Juxtapid (lomitapide) was approved by the FDA in 2012 to treat a rare, inherited cholesterol disorder known as Homozygous Familial Hypercholesterolemia (HoFH). In HoFH, patients cannot remove unwanted LDL (“bad cholesterol”) from their body, and often die from a heart attack before the age of thirty. It is used along with a low-fat diet and other cholesterol-lowering therapies, including LDL apheresis, where available.

It comes as an oral capsule that you take once per day on an empty stomach (at least 2 hours after dinner or evening snack). Take each dose with a glass of water. You will take the medicine daily until your doctor tells you to stop treatment. Do not stop treatment without talking to your doctor first.

Do not drink grapefruit juice or eat grapefruit while taking Juxtapid as this can lead to dangerous levels of Juxtapid in your blood. Also, do not have more than 1 alcoholic drink per day, because this may cause liver damage.

Juxtapid may decrease your body’s ability to absorb fat-soluble nutrients such as Vitamin E and fatty acids. Your doctor will recommend supplements you can take to replace these nutrients. Take the supplements in the morning with food.

Juxtapid can cause liver problems such as increased liver enzymes or increased fat in the liver. Your doctor will monitor your liver before and during treatment by ordering blood tests to check your liver. If your tests show signs of liver problems, your doctor may lower your dose or discontinue the medicine.

Learn More: Juxtapid Warnings, Precautions and Side Effects (in more detail)

Related questions

How much does Juxtapid lower cholesterol?

Juxtapid was evaluated in a 26-week long clinical trial of 29 patients taking other cholesterol-lowering medicines and also taking Juxtapid up to a maximum dose of 60 mg.

  • Low density lipoprotein cholesterol ("bad cholesterol") fell by an average of 40% and total cholesterol fell by 36% during the first 26 weeks of treatment.
  • These results were maintained over the next 12 months.

However, it is not known whether Juxtapid will lower your risk of problems due to high cholesterol like heart disease, stroke or heart-related death. Also, it is not known if Juxtapid is safe and effective in people with high cholesterol who do not have HoFH, including those with heterozygous familial hypercholesterolemia (HeFH).

This is not all the information you need to know about Juxtapid (lomitapide) for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.

  • Alonso R, Cuevas A, Mata P. Lomitapide: a review of its clinical use, efficacy, and tolerability. Core Evid. 2019 Jul 1;14:19-30. doi: 10.2147/CE.S174169. PMID: 31308834; PMCID: PMC6615460.
  • Juxtapid (lomitapide) prescribing information. 9/2020. Amryt Pharma. Dublin, Ireland. Accessed Feb. 20, 2023 at content/uploads/2021/01/prescribing-information.pdf
  • Amryt Pharma. Accessed Feb 20, 2023 at

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