Short answer: Skytrofa is injected under the skin once a week, at any time of day. Children take 0.24 mg/kg once weekly, with the cartridge picked from a weight table. Adults start at 1.4 mg (ages 30 to 60), 2.1 mg (under 30, or any age on oral estrogen) or 0.7 mg (over 60), raised monthly up to 6.3 mg once weekly.
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 Skytrofa is approved for: Skytrofa is a once-weekly growth hormone approved for children 1 year and older who weigh at least 11.5 kg and have growth failure from growth hormone deficiency, and to replace growth hormone in adults with growth hormone deficiency (section 1).
Source
SKYTROFA (lonapegsomatropin-tcgd) for injection, for subcutaneous use, prescribing information. Ascendis Pharma. DailyMed, version published October 26, 2026. DailyMed setid 9229f871-bc61-4ddc-8122-d126d40e36ac
Skytrofa is injected under the skin (subcutaneously) once weekly into the abdomen, buttock or thigh, rotating sites between and within regions (sections 2.1 and 2.7).
Each cartridge works only with the Skytrofa Auto-Injector, which mixes the powder and delivers the dose. A refrigerated cartridge sits at room temperature for 15 minutes first, and a mixed cartridge is used within 4 hours (section 2.7).
An eye (fundoscopic) exam is done before starting to rule out swelling of the optic nerve (section 2.1).
The table below is the label's schedule, from the Dosage and Administration section. Numbers are copied exactly; the section is in brackets.
| Weight (kg) | Dose (mg) |
|---|---|
| 11.5 – 13.9 | 3 |
| 14 – 16.4 | 3.6 |
| 16.5 – 19.9 | 4.3 |
| 20 – 23.9 | 5.2 |
| 24 – 28.9 | 6.3 |
| 29 – 34.9 | 7.6 |
| 35 – 41.9 | 9.1 |
| 42 – 50.9 | 11 |
| 51 – 60.4 | 13.3 |
| 60.5 – 69.9 | 15.2 (using two cartridges of 7.6 mg each) |
| 70 – 84.9 | 18.2 (using two cartridges of 9.1 mg each) |
| 85 – 100 | 22 (using two cartridges of 11 mg each) |
| Adult group | Starting dose |
|---|---|
| 30 to 60 years old, no oral estrogen | 1.4 mg once weekly |
| Under 30 years old, or any age taking oral estrogen | 2.1 mg once weekly |
| Over 60 years old, no oral estrogen | 0.7 mg once weekly |
| Maximum recommended dose | 6.3 mg once weekly |
The pediatric dose of 0.24 mg/kg once weekly applies both to children new to treatment and to those switching from another growth hormone, and is individualized based on response.
For a pediatric dose other than 0.24 mg/kg/week, the weekly dose in mg is the prescribed mg/kg times body weight, rounded to the closest cartridge strength.
Adult doses are raised monthly to a higher-strength cartridge based on clinical response and IGF-1 (drawn 4 to 5 days after the prior dose), and lowered for side effects or a weekly average IGF-1 above the age- and sex-specific normal range.
Children treated for growth hormone deficiency whose growth plates have closed are re-evaluated before continuing Skytrofa.
If somatropin-induced intracranial hypertension is confirmed, Skytrofa is restarted at a lower dose once the signs have resolved.
A missed dose is given as soon as possible and not more than 2 days after the missed day. Skytrofa can also be taken 2 days before or 2 days after the scheduled day, then the next dose goes back to the usual day. If more than 2 days have passed, the dose is skipped and the next one taken on the regular day. At least 5 days should pass between doses.
More on this: missed a dose of Skytrofa.
From daily somatropin: wait at least 8 hours between the last daily dose and the first Skytrofa dose (children and adults, sections 2.2 and 2.3).
From another once-weekly growth hormone: wait at least 7 days between the last dose of that product and the first Skytrofa dose (children and adults, sections 2.2 and 2.3).
If the regular dosing day is changed to a different day of the week, at least 5 days should pass between the last dose and the new regular day.
In Dose Track you set up Skytrofa 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.