RAVICTI® and Generic Glycerol Phenylbutyrate Updates
NUCDF is closely monitoring changes in RAVICTI® availability and the availability of generic glycerol phenylbutyrate. This page will be updated as new information becomes available.
Important Update About Amgen's RAVICTI Product Availability
September 15, 2026
NUCDF has been informed that Amgen plans to retire branded RAVICTI® (glycerol phenylbutyrate) oral liquid on December 31, 2026.
Amgen's current patient support programs, including Patient Access Liaisons (PALs), will continue through the product retirement date of December 31, 2026. According to Amgen, after the retirement date, RAVICTI may remain available through pharmacies and eligible to dispense to patients until quantities are depleted.
Several FDA approved generic versions of glycerol phenylbutyrate are now available. NUCDF has been closely monitoring access, pharmacy availability, patient experiences, and other issues related to these products.
We know this news may raise questions and concerns for individuals and families who rely on RAVICTI. Patients and caregivers should contact Amgen By Your Side at (855) 823-7878 for any questions.
What should families do now?
If you or your family member currently takes branded RAVICTI, we encourage you to speak with your metabolic team, specialty pharmacy, and insurance provider well before the end of the year to understand what alternative options may be available.
Please do not make changes to your medication without discussing them with your healthcare team.
NUCDF will continue working with families, clinicians, pharmacies, manufacturers, and other stakeholders to identify access concerns and share reliable information as the transition progresses.
If you have already transitioned to generic glycerol phenylbutyrate, we also encourage you to share your experience through the NUCDF Generic Medication Survey. The information families provide is helping us better understand what is happening across the UCD community.
NUCDF is committed to advocating for consistent, affordable, and reliable access to this essential therapy. We will continue to update the UCD community as additional information becomes available.
For live updates, continue to check this page. Reach out to us at info@nucdf.org with questions.
Generic Glycerol Phenylbutyrate Availability
NUCDF is monitoring the availability of FDA approved generic glycerol phenylbutyrate oral liquid, 1.1 g/mL.
According to the FDA Orange Book, six generic manufacturers have received FDA approval:
• Par Health / PH Health
• Aurobindo Pharma
• MSN
• Teva Pharmaceuticals
• Navinta LLC
• Lupin
FDA approval does not necessarily mean a product is immediately available through specialty pharmacies.
Availability may vary by pharmacy, insurance plan, and individual circumstances. Families should work with their metabolic team, specialty pharmacy, and insurance provider to understand which products may be available to them.
NUCDF will continue monitoring FDA approvals, product availability, access concerns, and community experiences.
Share Your Experience
If you or your family member has transitioned to generic glycerol phenylbutyrate, we want to hear from you.
The NUCDF Generic Medication Survey is helping us understand what families are experiencing, including:
• Pharmacy availability
• Insurance coverage
• Out of pocket costs
• Delays in accessing medication
• Experiences transitioning between products
• Differences noticed after a medication change
Complete the NUCDF Generic Medication Survey
The information families provide helps NUCDF identify trends, access concerns, and issues that may require additional follow up or advocacy.
Copay and Patient Assistance Resources
Financial assistance programs and eligibility requirements may vary by product and insurance coverage.
Current resources include:
• Par Health
• Lupin
• Good Days Patient Assistance
Families should verify current eligibility requirements and program details directly with the assistance program, manufacturer, specialty pharmacy, or insurance provider.
