Short answer: Both are growth hormone analogs injected under the skin once a week.12 Ngenla (somatrogon) is approved only for children 3 and older with growth hormone deficiency, at 0.66 mg/kg a week. Sogroya (somapacitan) covers children 2.5 and older with growth hormone deficiency or three other causes of short stature, and adults with growth hormone deficiency. Both allow a missed dose within 3 days. Neither has a boxed warning.
| Sogroya | Ngenla | |
|---|---|---|
| Drug | Somapacitan-beco1 | Somatrogon-ghla2 |
| Children | Age 2.5 and older with growth hormone deficiency, born small for gestational age without catch-up growth, Noonan syndrome or idiopathic short stature1 | Age 3 and older with growth failure from growth hormone deficiency2 |
| Adults | Approved for adults with growth hormone deficiency1 | Not approved for adults2 |
| Child dose | 0.16 mg/kg a week for growth hormone deficiency; 0.24 mg/kg a week for the other uses1 | 0.66 mg/kg a week2 |
| Adult dose | Start 1.5 mg a week, raised every 2 to 4 weeks, up to 8 mg1 | Not applicable2 |
| Missed dose | Taken within 3 days after the scheduled day; after that, skipped1 | Given as soon as possible within 3 days; after that, skipped2 |
| From daily growth hormone (children) | Last daily dose the day before, or at least 8 hours before, the first Sogroya dose1 | Start the day after the last daily injection2 |
| Child trial vs daily somatropin | Headache 12.1% vs 8.8%, pain in arms or legs 9.8% vs 2.9%, injection site reaction 6.1% vs 5.9%1 | Injection site reaction 42.2% vs 25.2%, colds and sore throat 33% vs 28.7%, headache 16.5% vs 21.7%2 |
| Boxed warning | None1 | None2 |
Both labels carry the growth hormone class warnings: higher death rates in acute critical illness, tumor risk, effects on blood sugar, raised pressure in the skull with an eye exam before starting, fluid retention, low cortisol, thyroid changes, hip problems in children, scoliosis, pancreatitis, and fat changes where the same spot is injected for a long time.12 Neither is approved for growth failure from Prader-Willi syndrome. Ngenla's injection site reactions were recorded in a diary after every injection and were mostly pain at the site, 39% vs 25% on daily somatropin.2 These numbers come from separate trials with different people, lengths and methods, so they are not a head-to-head comparison.
Which, if either, fits is for your prescriber. More detail: Sogroya side effects, Ngenla side effects, the Sogroya and Ngenla dosing schedules, the Sogroya and Ngenla missed-dose pages, and Sogroya vs daily growth hormone: what changes with a weekly shot?.