Ctexli (chenodiol (chenodeoxycholic acid))
An approved treatment for Cerebrotendinous Xanthomatosis.
The same compound appears under different names depending on the context. Here is how to identify Chenodiol (chenodeoxycholic acid) wherever you encounter it, plus the key facts at a glance.
- Generic name
- Chenodiol (chenodeoxycholic acid)
- Brand name
- Ctexli
- Drug class
- Bile acid
- Manufacturer
- Mirum Pharmaceuticals
- How it's taken
- Ctexli is taken as 250 mg tablets three times daily by mouth.
The first FDA-approved therapy specifically for cerebrotendinous xanthomatosis (CTX). Ctexli replaces the bile acid CTX patients are missing because of CYP27A1 deficiency, lowering the toxic buildup of cholestanol that damages the brain, tendons, eyes, and arteries. Approved on February 21, 2025 for treatment of CTX in adults.
Where Chenodiol (chenodeoxycholic acid) fits
First and only FDA-approved therapy specifically for cerebrotendinous xanthomatosis (approved February 21, 2025, and still the only one as of September 2026). The approved indication is for adults; pediatric use remains off-label. Statin therapy is sometimes added to address premature coronary artery disease in CTX patients, though statins do not correct the underlying enzyme defect.
How Chenodiol (chenodeoxycholic acid) works
In CTX, a defective enzyme called sterol 27-hydroxylase prevents the body from converting cholesterol into chenodeoxycholic acid (CDCA), one of the body's two main bile acids. Without that conversion step, the body keeps trying to make bile acids using a different pathway, which floods the body with a related compound called cholestanol. Cholestanol slowly deposits in the brain, tendons, lens of the eye, and arteries, where it causes damage over decades.
Ctexli is purified chenodeoxycholic acid taken by mouth. It directly replaces the missing bile acid, restores feedback signals that tell the body to slow cholesterol-to-bile-acid production, and lowers cholestanol levels in blood and tissues. It does not fix the underlying genetic defect, so it must be taken long-term.
Mechanism: Bile acid replacement therapy. Substitutes for chenodeoxycholic acid (CDCA), the bile acid CTX patients cannot synthesize, restoring negative feedback on cholesterol-to-bile-acid pathways and reducing toxic accumulation of cholestanol.
Side effects and safety
Common side effects include diarrhea, headache, abdominal pain, constipation, hypertension, muscular weakness, and upper respiratory tract infection. The label includes a warning for liver toxicity, especially in patients with pre-existing liver disease or bile duct abnormalities. Liver enzyme monitoring is required before and during treatment.
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Chenodiol (chenodeoxycholic acid)
Ctexli is taken as 250 mg tablets three times daily by mouth. Liver function tests are obtained at baseline and monitored regularly during treatment. Patients with pre-existing liver disease or biliary tract abnormalities require closer monitoring or may not be candidates for therapy.
Availability and cost
Only available as the brand-name product.
Targeted therapy for an ultra-rare disease with no other FDA-approved alternative. Coverage typically requires biochemical or genetic confirmation of CTX. Mirum operates a patient assistance program for patients who qualify for financial help; eligibility criteria are not published.
Help paying for Ctexli
Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.
- Copay help
Mirum Access Plus Savings Program: eligible patients with commercial or private insurance may pay as little as $0 per fill.
For: private insurance · source - Insurance and case manager help
A Patient Navigator helps with insurance coverage, approvals and appeals, and coordinates home delivery through the MAP pharmacy.
The official page does not say who qualifies. Ask the program. · source - Free medicine program
Mirum Patient Assistance Program gives support to patients who qualify for financial help; eligibility criteria are not published.
The official page does not say who qualifies. Ask the program. · source
Good to know: The official page does not say who qualifies for the Mirum Patient Assistance Program (for example, uninsured) or whether it provides free drug.
- From a charity · NORD RareCareCTX Medical Assistance fundOpen
Pays for: Medical and medication costs.
The foundation says: “Accepting Applications” - From a charity · NORD RareCareCTX Premium Copay Assistance fundOpen
Pays for: Insurance premiums and copays.
The foundation says: “Accepting new applications and re-enrollments for current year”
Clinical trial results
FDA approval was based on the Phase 3 RESTORE study (NCT04270682), a 24-week double-blind, placebo-controlled, randomized crossover withdrawal trial in adults with CTX. Treatment with chenodiol 250 mg three times daily produced a statistically significant reduction in plasma cholestanol and in urinary 23S-pentol (a CTX-specific bile alcohol marker) compared with placebo, supporting the conclusion that Ctexli corrects the metabolic defect of CTX.
Development history
Chenodiol was first approved in the U.S. in 1983 to dissolve gallstones. It was later sold as Chenodal, which the FDA recognized as medically necessary for CTX even though CTX was not on its label. Mirum Pharmaceuticals bought chenodiol from Travere Therapeutics in August 2023 and completed the RESTORE withdrawal trial to show ongoing biochemical benefit. The FDA granted approval on February 21, 2025, making chenodiol the first drug approved with a CTX-specific indication. Before this approval, most U.S. patients used Chenodal off-label under the FDA's medical necessity recognition, and some imported the drug from Europe (where Leadiant's Xenbilox has been authorized).
Explore Cerebrotendinous Xanthomatosis trials
Common questions about Chenodiol (chenodeoxycholic acid)
▸What is Chenodiol (chenodeoxycholic acid) (Ctexli)?
The first FDA-approved therapy specifically for cerebrotendinous xanthomatosis (CTX). Ctexli replaces the bile acid CTX patients are missing because of CYP27A1 deficiency, lowering the toxic buildup of cholestanol that damages the brain, tendons, eyes, and arteries. Approved on February 21, 2025 for treatment of CTX in adults.
▸How does Chenodiol (chenodeoxycholic acid) work?
In CTX, a defective enzyme called sterol 27-hydroxylase prevents the body from converting cholesterol into chenodeoxycholic acid (CDCA), one of the body's two main bile acids. Without that conversion step, the body keeps trying to make bile acids using a different pathway, which floods the body with a related compound called cholestanol. Cholestanol slowly deposits in the brain, tendons, lens of the eye, and arteries, where it causes damage over decades.
Ctexli is purified chenodeoxycholic acid taken by mouth. It directly replaces the missing bile acid, restores feedback signals that tell the body to slow cholesterol-to-bile-acid production, and lowers cholestanol levels in blood and tissues. It does not fix the underlying genetic defect, so it must be taken long-term.
▸What are the side effects of Chenodiol (chenodeoxycholic acid)?
Common side effects include diarrhea, headache, abdominal pain, constipation, hypertension, muscular weakness, and upper respiratory tract infection. The label includes a warning for liver toxicity, especially in patients with pre-existing liver disease or bile duct abnormalities. Liver enzyme monitoring is required before and during treatment.
▸How is Chenodiol (chenodeoxycholic acid) taken?
Ctexli is taken as 250 mg tablets three times daily by mouth. Liver function tests are obtained at baseline and monitored regularly during treatment. Patients with pre-existing liver disease or biliary tract abnormalities require closer monitoring or may not be candidates for therapy.
▸Is Chenodiol (chenodeoxycholic acid) FDA approved?
Yes, Chenodiol (chenodeoxycholic acid) (Ctexli) is FDA approved (2025) for the treatment of Cerebrotendinous Xanthomatosis.
▸Is Ctexli the first FDA-approved treatment for CTX?
Yes. On February 21, 2025, the FDA approved Ctexli (chenodiol) for treatment of cerebrotendinous xanthomatosis in adults. Before this approval, U.S. patients accessed chenodeoxycholic acid off-label, through compounding pharmacies, or by importing the drug from Europe.
▸Can children with CTX take Ctexli?
The FDA-approved indication for Ctexli covers adults only. Pediatric use is off-label. CTX often presents in childhood with chronic diarrhea or juvenile cataracts, and clinicians may use chenodiol off-label in pediatric patients based on the strong rationale for early treatment, but this should be coordinated with a metabolic specialist or neurologist familiar with the disease.
▸Why is early treatment so important in CTX?
The neurologic damage in CTX, including cerebellar ataxia, cognitive decline, and seizures, is largely irreversible once it develops. Long-term bile acid replacement started early in life can stabilize or prevent neurologic decline. Patients diagnosed in adulthood, after years of accumulating cholestanol in the brain, may see their disease stabilize on Ctexli but cannot recover function that has already been lost.
▸How is Ctexli monitored?
Treatment includes baseline and ongoing liver function tests because of a hepatotoxicity warning on the label. Plasma cholestanol levels and urinary bile alcohol markers (such as 23S-pentol) can be tracked to confirm the drug is working. Cardiology and ophthalmology follow-up addresses the systemic complications of CTX, since Ctexli treats the underlying defect but does not reverse coronary or lens damage already present.
▸Should asymptomatic siblings of a CTX patient be tested?
Yes, this should be discussed with a genetic counselor or metabolic specialist. CTX is autosomal recessive, so a sibling has a 25% chance of having the disease. Because early treatment can prevent neurologic decline, identifying and treating an asymptomatic sibling before symptoms appear can change their lifetime trajectory.
Sources and references
Every factual claim on this page is drawn from the public sources listed below. Click any reference to open the original document.
- U.S. Food and Drug Administration · February 2025. CTEXLI (chenodiol) tablets — Prescribing Information. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/219488s000lbl.pdf
- Mirum Pharmaceuticals via PR Newswire · February 21, 2025. FDA Approves First Treatment for Cerebrotendinous Xanthomatosis, a Rare Lipid Storage Disease. https://www.prnewswire.com/news-releases/fda-approves-first-treatment-for-cerebrotendinous-xanthomatosis-a-rare-lipid-storage-disease-302382475.html
- ClinicalTrials.gov. Study to Evaluate Patients With Cerebrotendinous Xanthomatosis (RESTORE). https://clinicaltrials.gov/study/NCT04270682
- NCBI Bookshelf / GeneReviews. Cerebrotendinous Xanthomatosis. https://www.ncbi.nlm.nih.gov/books/NBK1409/