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Crysvita Side Effects

Generic name: burosumab

Medically reviewed by Last updated on Nov 6, 2023.

Note: This document contains side effect information about burosumab. Some dosage forms listed on this page may not apply to the brand name Crysvita.

Applies to burosumab: subcutaneous solution.

Serious side effects of Crysvita

Along with its needed effects, burosumab (the active ingredient contained in Crysvita) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking burosumab:

More common

Other side effects of Crysvita

Some side effects of burosumab may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

For Healthcare Professionals

Applies to burosumab: subcutaneous solution.


The more commonly reported adverse reactions have included injection site reactions, muscle spasms, back pain, tooth infections, restless leg syndrome, dizziness, headache, decreased vitamin D, and constipation.[Ref]


Very common (10% or more): Vitamin D decreased (up to 37%)

Common (1% to 10%): Blood phosphorus increased

Increased blood phosphorus was reported in 6% of adult patients during clinical trials. There were no reports of increased blood phosphorus in pediatric clinical trials.


Very common (10% or more): Vomiting (up to 48%), toothache (up to 23%), tooth abscess (up to 34%), dental caries (up to 31%), diarrhea (up to 24%), constipation (up to 17%)

Common (1% to 10%): Nausea


Frequency not reported: Hypersensitivity reactions

In pediatric patients, the more frequent events that were considered potential hypersensitivity events included rash (22%), injection site rash (6%), and urticaria (5%). In adult patients approximately 6% of patients in both the study group and placebo group experience mild or moderate hypersensitivity reactions that did not require drug discontinuation.


Very common (10% or more): Rash (up to 27%)

Rash includes pruritic, maculopapular, and pustular rashes


Very common (10% or more): Extremity pain (up to 46%), myalgia (up to 17%), back pain (15%); muscle spasm (up to 19%)

Common (1% to 10%): Spinal surgery

Spinal stenosis is common in adults with X-linked hypophosphatemia (XLH). In phase 2/3 studies, 6 patients (n=176) underwent spinal surgery for what appeared to involve progression of a preexisting spinal stenosis. It is unknown if therapy exacerbates spinal stenosis or spinal cord compression.


Very common (10% or more): Pyrexia (up to 55%)


Very common (10% or more): Injection site reaction (up to 67%)

Injection site reactions have included erythema, pruritus, swelling, pain, rash, bruising, discoloration, discomfort, hematoma, hemorrhage, induration, macule, and urticaria at the injection site

Nervous system

Very common (10% or more): Headache (up to 73%), dizziness (up to 15%), restless leg syndrome (12%)


Very common (10% or more): Cough (up to 52%)

Frequently asked questions


1. Product Information. Crysvita (burosumab). Ultragenyx Pharmaceutical. 2018.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.