Full Prescribing Information Important Safety Information

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Our legacy

Sobi, the manufacturer of Orfadin® (nitisinone), is a leading biopharmaceutical company dedicated to bringing innovative therapies and services to improve the lives of everyone affected by rare disease.

For over 25 years, we've been studying tyrosinemia, investing in nitisinone's clinical development, and helping to address the varied and nuanced needs of patients with HT-1.

Nitisinone was developed for clinical use by two Swedish scientists in 1989 and was subsequently commercialized by Sobi. The launch of Orfadin signaled the beginning of our commitment to the HT-1 community.

Sara, Tasneem's mom
All individuals featured in this website have experience with Orfadin but may no longer be on treatment.

A history of orfadin

  • 1982 Nitisinone is extracted from the bottle brush plant

  • 1989 A research group at the University of Gothenburg in Sweden presents groundbreaking findings that lead to a concept for treating patients with HT-1

  • 1992 Clinical trials results of nitisinone are published in The Lancet, an international medical journal

  • 2002 The FDA approves Orfadin

  • 2005 The EU approves Orfadin under the new EU orphan drug legislation

  • 2007 Sobi hosts the first-ever international tyrosinemia scientific symposium

  • 2013 The Orfadin Post Authorization Long-term Safety Study (OPAL) begins
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  • 2014 Launch of Orfadin4U, our patient support program

  • 2015 An oral suspension and 20-mg capsule are added to Orfadin's dosing options

  • 2016 Orfadin is now able to be stored at room temperature (up to 45 days for capsules and 60 days for oral suspension)

  • 2017 A once-daily treatment option is added to Orfadin's dosing options for patients 5 years and older who have undetectable serum and urine succinylacetone concentrations after a minimum of 4 weeks on a stable dosage of nitisinone

  • What's next? Ongoing studies of Orfadin use are underway. Results will be announced once they are available.

All individuals featured in this website have experience with Orfadin but may no longer be on treatment.

Our commitment to you

As the first and longest-running supplier of HT-1 treatment, we strive to go above and beyond to ensure that our 150+ patients always have the medicine they need. To that end, we're proud of our ongoing commitment to always having Orfadin in stock.

All individuals featured in this website have experience with Orfadin but may no longer be on treatment.

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Tips, news, information + more


Orfadin is a synthetic reversible inhibitor of 4-hydroxyphenylpyruvate dioxygenase indicated for use as an adjunct to dietary restriction of tyrosine and phenylalanine in the treatment of hereditary tyrosinemia type 1 (HT-1).


Tyrosine levels can increase in the blood if you do not restrict tyrosine and phenylalanine in your diet while taking Orfadin. Too much tyrosine in the blood can cause serious eye problems or other complications.

Do not adjust your Orfadin dosage in order to lower the tyrosine levels in the blood.

A reduction in the number of white cells and platelets in the blood have been observed during treatment with Orfadin. Your platelet and white blood cell counts should be monitored regularly during Orfadin treatment.

The most common adverse reactions to taking Orfadin are elevated tyrosine levels, low platelets or white cells in the blood, and complaints related to the eyes, including conjunctivitis, corneal opacity, inflammation of the cornea, and extreme sensitivity to light.

Tell your physician promptly if you have unexplained eye symptoms, rash, jaundice (yellowing of the skin or whites of the eyes) or excessive bleeding.

Use Orfadin during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Nursing women should discontinue either Orfadin or breast-feeding based on the recommendation of your healthcare professional.

Please see full Prescribing Information