Information for US patients

Frequently Asked Questions (FAQs)

Phenylketonuria (PKU)

PKU is an inherited disorder caused by a deficiency of an enzyme (phenylalanine hydroxylase, sometimes known as PAH). The PAH enzyme is needed to process phenylalanine, which is found in all foods containing protein.¹

Find out more about PKU

The first line of therapy to treat PKU is a phenylalanine-restricted diet. This involves medical foods which have been modified to be low in protein, and medical formula which provides the nutrients a person without PKU would typically get from protein.²

In addition to the phenylalanine-restricted diet, some patients with PKU also take a medication called sapropterin dihydrochloride, the active ingredient in JAVYGTOR. This medication helps the PAH enzyme work more effectively to break down phenylalanine in the body.³

Find out more about JAVYGTOR

JAVYGTOR (sapropterin dihydrochloride) Tablets for Oral Use and Powder for Oral Solution

JAVYGTOR is a generic version of Kuvan®. This means that both products contain the same active ingredient – sapropterin dihydrochloride – and both products act the same way in the body.³

For further information, please contact Cycle Vita – +1 (888) 360-8482 – and ask to speak with our Medical Affairs department.

Find out more about JAVYGTOR

KUVAN® is a registered trademark of BioMarin Pharmaceutical Inc. Developed in collaboration with Asubio Pharma Co., Ltd.

Sapropterin dihydrochloride is the active ingredient in JAVYGTOR and is a proven treatment for PKU. In patients who respond, sapropterin dihydrochloride stimulates the PAH enzyme to break down phenylalanine in the body.³

Find out more about JAVYGTOR

JAVYGTOR is the same proven sapropterin dihydrochloride you may have taken previously,¹ and comes with Cycle Vita, our dedicated support platform. The Cycle Vita team are here to support* you throughout your JAVYGTOR treatment journey.

Find out more about JAVYGTORFind out more about Cycle Vita

If you are interested in being prescribed JAVYGTOR talk to your doctor about why you think the medication would be suited to your needs. To be prescribed JAVYGTOR you will need your doctor to complete an enrollment form:

Enrollment form

If you or your doctor have any questions, please contact the Cycle Vita team at +1 (888) 360-8482.

Find out more about JAVYGTOR

It is very important that you continue to follow the phenylalanine (phe)-restricted diet your doctor has prescribed while you take JAVYGTOR.³

Always consult with your dietitian before considering any changes in your diet plan.

Find out more about the PKU diet

Not all patients with PKU respond to sapropterin dihydrochloride and so in some cases a trial is required before JAVYGTOR treatment can fully initiate.

  • You are eligible for JAVYGTOR without a trial if you have responded to sapropterin therapy previously.
  • For patients new to sapropterin therapy, the ACMG recommends a trial to assess their responsiveness to the medication.²
Find out more about the New Patient Free Trial

Cycle Vita

The Cycle Vita team will be just a phone call away. You can expect to hear from two types of people at Cycle Vita:

  • Access Specialists – help you access JAVYGTOR through enrollment, financial and pharmacy support*
  • Clinical Specialists – provide clinical education, nutrition support and medication administration support*

A friendly, familiar team is waiting here at Cycle Vita, for you, at every step.

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+1 (888) 360-8482

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Find out more about Cycle Vita

As part of your JAVYGTOR therapy, you will gain access to Cycle Vita, our dedicated support platform. From Cycle Vita you can expect to receive, subject to eligibility:

  • Access Support*- financial, logistics and educational support including Co-pay Programs
  • Clinical Support*- including continuous access to a Registered Dietitian
Find out more about Cycle Vita

If you are a commercially insured eligible patient who has been prescribed JAVYGTOR, you may pay as little as $0 in co-pay*. To find out more about eligibility criteria please contact Cycle Vita on +1 (888) 360-8482.

Find out more about Cycle Vita

We understand that there are some circumstances outside of your control whereby you might need medication urgently to fill a gap in your supply and ensure that you remain on therapy.

Eligible* patients prescribed JAVYGTOR can access the following:

  • Bridge Program: A free supply of JAVYGTOR is available to allow patients to begin therapy immediately while Cycle Vita secures appropriate Benefit Verification and assists with Prior Authorization. The Bridge Program may also be requested if you're an existing patient who are temporarily experiencing disruption in therapy due to insurance coverage
Find out more about Cycle Vita

There are a wide range of resources available online to support you, wherever you are in your PKU treatment journey. Please refer to our Useful Resources page for more information.

Useful resources


1. National Institutes of Health. Phenylketonuria (PKU). Available at: (Accessed February 12th, 2024).)

2. Vockley J., et al; for the American College of Medical Genetics and Genomics Therapeutic Committee. Phenylalanine hydroxylase deficiency: diagnosis and
management guideline. Genet Med. 2014;16(2):188 200. doi:10.1038/gim.2013.157

3. JAVYGTOR (sapropterin dihydrochloride). Prescribing Information. Dr Reddy’s Laboratories Ltd.

*Some areas of support may not be accessible to all patients. Eligibility criteria may apply to ensure compliance with all applicable federal and state requirements, and benefits may be limited to commercially insured patients only. For more detailed information about eligibility, terms and conditions, please contact the Cycle Vita team at +1 (888) 360-8482.