Short answer: Voxzogo is injected under the skin once a day, at about the same time each day if possible. The dose is set by the child's actual body weight, from 0.096 mg at 3 kg to 0.8 mg at 90 kg or more, and is adjusted as the child grows. Each vial is mixed before use and given within 3 hours. A missed dose can be given within 12 hours; after that it is skipped.
This is what the FDA label says. Follow your prescriber. Your prescriber may use a different dose or pace than the label's standard schedule.
What Voxzogo is approved for: Voxzogo is a C type natriuretic peptide (CNP) analog approved to increase linear growth in children with achondroplasia whose growth plates (epiphyses) are still open. It has accelerated approval based on faster yearly growth, and continued approval may depend on confirmatory trials (section 1).
Source
VOXZOGO (vosoritide) for injection, for subcutaneous use, prescribing information, Patient Information and Instructions for Use. BioMarin. DailyMed, version published November 26, 2025. DailyMed setid 228e8560-04a4-4bb1-a81f-29531a9e4d27
Voxzogo is injected under the skin once a day, at about the same time each day if possible. Before each dose the child eats enough and drinks about 240 to 300 mL of fluid in the hour before the injection (sections 2.1 and 2.2).
Each vial is mixed with the supplied prefilled syringe of sterile water, swirled gently and not shaken. The mixed vial can be held at room temperature for at most 3 hours. Only 1 dose is taken from each vial, and leftovers are not pooled (section 2.4).
Injection sites are the front middle of the thighs, the lower abdomen at least 2 inches from the navel, the top of the buttocks or the back of the upper arms. The same area is not used on two days in a row (section 2.4). Caregivers inject after training by a healthcare professional.
The table below is the label's schedule, from the Dosage and Administration section. Numbers are copied exactly; the section is in brackets.
| Actual Body Weight | Dose | Injection Volume | Vial Strength for Reconstitution |
|---|---|---|---|
| 3 kg | 0.096 mg | 0.12 mL | 0.4 mg |
| 4 kg | 0.12 mg | 0.15 mL | 0.4 mg |
| 5 kg | 0.16 mg | 0.2 mL | 0.4 mg |
| 6 to 7 kg | 0.2 mg | 0.25 mL | 0.4 mg |
| 8 to 11 kg | 0.24 mg | 0.3 mL | 0.4 mg |
| 12 to 16 kg | 0.28 mg | 0.35 mL | 0.56 mg |
| 17 to 21 kg | 0.32 mg | 0.4 mL | 0.56 mg |
| 22 to 32 kg | 0.4 mg | 0.5 mL | 0.56 mg |
| 33 to 43 kg | 0.5 mg | 0.25 mL | 1.2 mg |
| 44 to 59 kg | 0.6 mg | 0.3 mL | 1.2 mg |
| 60 to 89 kg | 0.7 mg | 0.35 mL | 1.2 mg |
| ≥ 90 kg | 0.8 mg | 0.4 mL | 1.2 mg |
Weights in between bands are rounded to the nearest whole number. Mixed 0.4 mg and 0.56 mg vials are 0.8 mg/mL; a mixed 1.2 mg vial is 2 mg/mL, which is why the injection volume drops at 33 kg.
| Vial Strength | Reconstitution Volume | Reconstituted Concentration |
|---|---|---|
| 0.4 mg | 0.5 mL | 0.8 mg/mL |
| 0.56 mg | 0.7 mL | 0.8 mg/mL |
| 1.2 mg | 0.6 mL | 2 mg/mL |
Body weight, growth and physical development are checked every 3 to 6 months, and the dose is adjusted to the actual body weight.
Voxzogo is stopped for good once there is no further growth potential, shown by closure of the growth plates.
Voxzogo is not recommended for people with an eGFR under 60 mL/min/1.73 m2.
Vials and diluent syringes are refrigerated at 2 C to 8 C (36 F to 46 F) and not frozen. Unmixed Voxzogo can be kept at room temperature, 20 C to 25 C (68 F to 77 F), for 90 days, and is not put back in the refrigerator after that.
The label says: "If a dose of VOXZOGO is missed, it can be administered within 12 hours of the scheduled time of administration. Beyond 12 hours, skip the missed dose and administer the next daily dose according to the usual dosing schedule." The Patient Information says the same.
More on this: missed a dose of Voxzogo.
In Dose Track you set up Voxzogo as a protocol with the dose and schedule your prescriber gave you. A protocol can hold dose steps, each with its own dose and length in days or weeks, so a step-up plan like the one on the label can be entered once and the app moves to the next step on its own. Reminders follow the schedule, and every dose is logged with the date and time, so you can see which step you are on and when your last dose was. The app follows what you enter; it does not choose or change a dose.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.