This website is intended for residents of the U.S. interested in achondroplasia or VOXZOGO

Understanding bone growth and how VOXZOGO works

In achondroplasia, bone growth is impaired

Most bones start to grow before birth and continue for as long as the bones’ growth plates stay open. While the growth plates are open, there is an opportunity for growth.

Achondroplasia affects endochondral bone growth—this is bone growth that replaces cartilage with bone tissue as your child grows. Endochondral bone growth occurs in over 90% of bones in the body and takes place at the growth plate.

Skeletal Chart illustration

A balance is important for bone growth

A balance between fibroblast growth factor receptor 3 (FGFR3) and C-type natriuretic peptide (CNP) signaling pathways occurs within the cells in the growth plate.

Bone development without achondroplasia

FGFR3 slows bone growth while CNP promotes bone growth

Graphic to illustrate balance between (FGFR3) (CNP) relating to normal bone growth

This graphic illustrates the relationship between FGFR3 and CNP, and does not reflect the changing nature of the body’s signaling and bone growth processes.

Bone development with achondroplasia

In achondroplasia, FGFR3 sends more signals to slow bone growth than it should. The body’s CNP is not enough to balance overactive FGFR3 signaling.
Achondroplasia tilts the balance and slows down bone growth

This graphic illustrates the relationship between FGFR3 and CNP, and does not reflect the changing nature of the body’s signaling and bone growth processes.

VOXZOGO is a molecule that stimulates the CNP pathway

VOXZOGO works alongside the body’s natural CNP to stimulate the CNP signaling pathway to promote bone growth.

VOXZOGO bolsters CNP signaling to improve the balance with overactive FGFR3 signaling

Graphic shows how VOXZOGO works to increase CNP signaling in patients with achondroplasia

This graphic shows how VOXZOGO works to increase CNP signaling but is not to scale and and does not reflect a percentage of growth.

Want to learn more about VOXZOGO? Get email updates or get in touch with a local BioMarin representative


What is the most important safety information about VOXZOGO?

  • VOXZOGO may cause serious side effects including a temporary decrease in blood pressure in some patients. To reduce the risk of a decrease in blood pressure and associated symptoms (dizziness, feeling tired, or nausea), patients should eat a meal and drink 8 to 10 ounces of fluid within 1 hour before receiving VOXZOGO.

What are the most common side effects of VOXZOGO?

  • The most common side effects of VOXZOGO include injection site reactions (including redness, itching, swelling, bruising, rash, hives, and injection site pain), high levels of blood alkaline phosphatase shown in blood tests, vomiting, joint pain, decreased blood pressure, and stomach ache. These are not all the possible side effects of VOXZOGO. Ask your healthcare provider for medical advice about side effects, and about any side effects that bother the patient or that do not go away.

How is VOXZOGO taken?

  • VOXZOGO is taken daily as an injection given under the skin, administered by a caregiver after a healthcare provider determines the caregiver is able to administer VOXZOGO. Do not try to inject VOXZOGO until you have been shown the right way by your healthcare provider. VOXZOGO is supplied with Instructions for Use that describe the steps for preparing, injecting, and disposing VOXZOGO. Caregivers should review the Instructions for Use for guidance and any time they receive a refill of VOXZOGO in case any changes have been made.
  • Inject VOXZOGO 1 time every day, at about the same time each day. If a dose of VOXZOGO is missed, it can be given within 12 hours from the missed dose. After 12 hours, skip the missed dose and administer the next daily dose as usual.
  • The dose of VOXZOGO is based on body weight. Your healthcare provider will adjust the dose based on changes in weight following regular check-ups.
  • Your healthcare provider will monitor the patient’s growth and tell you when to stop taking VOXZOGO if they determine the patient is no longer able to grow. Stop administering VOXZOGO if instructed by your healthcare provider.

What should you tell the doctor before or during taking VOXZOGO?

  • Tell your doctor about all of the patient’s medical conditions including
    • If the patient has heart disease (cardiac or vascular disease), or if the patient is on blood pressure medicine (anti-hypertensive medicine).
    • If the patient has kidney problems or renal impairment.
    • If the patient is pregnant or plans to become pregnant. It is not known if VOXZOGO will harm the unborn baby.
    • If the patient is breastfeeding or plans to breastfeed. It is not known if VOXZOGO passes into breast milk.
  • Tell your doctor about all of the medicines the patient takes, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

You may report side effects to BioMarin at 1-866-906-6100. You are encouraged to report negative side effects of prescription drugs to the FDA. Visit, or call 1-800-FDA-1088.

Please see additional safety information in the full Prescribing Information and Patient Information.


What is VOXZOGO used for?

  • VOXZOGO is a prescription medicine used to increase linear growth in children with achondroplasia and open growth plates (epiphyses).
  • VOXZOGO is approved under accelerated approval based on an improvement in annualized growth velocity. Continued approval may be contingent upon verification and description of clinical benefit in confirmatory trials.