Short answer: In the label's 12-month trial in children, the most common Ngenla side effect was an injection site reaction (42.2% vs 25.2% on daily somatropin), mostly pain at the site (39% vs 25%). Next came colds and sore throat (33% vs 28.7%), headache (16.5% vs 21.7%), fever (16.5% vs 14.8%) and anemia (9.2% vs 8.7%). There is no boxed warning.
What Ngenla is approved for: Ngenla is a once-weekly growth hormone analog approved for children aged 3 years and older who have growth failure because their bodies do not make enough growth hormone (section 1). It is not approved for adults.
Source
NGENLA (somatrogon-ghla) injection, for subcutaneous use, prescribing information and Patient Information. Pfizer. DailyMed, version published August 19, 2026. DailyMed setid 06dce529-b741-4a1b-8842-3ad77be6e308
No. The current Ngenla label has no boxed warning.
These are the label's own numbers from the Adverse Reactions section. Where the label compares with placebo (a dummy treatment), both columns are shown, so you can see how much more often a reaction happened on Ngenla.
| Adverse Drug Reactions | Daily Somatropin (N=115) n (%) | Ngenla (N=109) n (%) |
|---|---|---|
| Injection site reactions | 29 (25.2) | 46 (42.2) |
| Nasopharyngitis | 33 (28.7) | 36 (33) |
| Headache | 25 (21.7) | 18 (16.5) |
| Pyrexia | 17 (14.8) | 18 (16.5) |
| Anemia | 10 (8.7) | 10 (9.2) |
| Cough | 9 (7.8) | 9 (8.3) |
| Vomiting | 9 (7.8) | 8 (7.3) |
| Hypothyroidism | 3 (2.6) | 7 (6.4) |
| Abdominal pain | 8 (7.0) | 7 (6.4) |
| Rash | 7 (6.1) | 6 (5.5) |
| Oropharyngeal pain | 4 (3.5) | 6 (5.5) |
| Arthralgia | 8 (7.0) | 5 (4.6) |
| Otitis media | 10 (8.7) | 5 (4.6) |
| Tonsillitis | 6 (5.2) | 5 (4.6) |
| Bronchitis | 9 (7.8) | 3 (2.8) |
Children aged 3 to 11 with growth hormone deficiency: Ngenla 0.66 mg/kg once weekly vs daily somatropin 0.034 mg/kg/day. Injection site reactions were collected with a diary after each weekly injection. They included pain (39% Ngenla vs 25% somatropin), swelling, hardening or inflammation (10% vs 1%), redness (8% vs none), itching (5% vs none) and bleeding (5% vs none). Nasopharyngitis includes rhinitis and pharyngitis.
More children on Ngenla moved from normal to raised eosinophil (a type of white blood cell) levels by the end of the 12-month study: 29% vs 12% on daily somatropin.
Reported after approval with somatropin products or Ngenla: fat loss at injection sites (lipoatrophy), osteonecrosis in children and slipped capital femoral epiphysis.
The Warnings and Precautions part of the label lists these. Each line gives the label's heading and what it means in plain words.
Acute critical illness. Higher death rates have been reported in critically ill people after open heart or abdominal surgery, multiple injuries or acute respiratory failure given somatropin. Ngenla is contraindicated in them.
Severe allergic reactions. Anaphylaxis and angioedema have been reported with somatropin. The label says prompt medical attention should be sought if an allergic reaction occurs.
Tumors. Active cancer can progress on somatropin, so any cancer must be inactive and its treatment complete first. Childhood cancer survivors treated with head or brain radiation had a higher risk of a second tumor, most often meningiomas. Moles are watched for growth or changes.
Blood sugar and diabetes. Growth hormone may lower insulin sensitivity, especially at higher doses. New type 2 diabetes has been reported, and undiagnosed pre-diabetes or diabetes may worsen. Glucose is checked periodically, and diabetes medicine doses may need adjusting.
Raised pressure in the skull. Intracranial hypertension with swelling of the optic nerve, vision changes, headache, nausea or vomiting has been reported, usually within the first 8 weeks. An eye exam is done before starting and periodically after, and Ngenla is paused if there are signs of it.
Fluid retention. Swelling and nerve compression such as carpal tunnel syndrome or tingling may occur. These are usually temporary and dose dependent.
Low cortisol. Children with or at risk of pituitary hormone deficiencies may develop low cortisol or unmasked secondary adrenal insufficiency, and those already on steroid replacement may need higher doses.
Thyroid. Untreated hypothyroidism can blunt the response, and central hypothyroidism may appear or worsen during treatment, so thyroid tests are done periodically.
Hip problems. Slipped capital femoral epiphysis, sometimes with bone death (osteonecrosis), has been reported with somatropin products or Ngenla. A child who starts limping or has persistent hip or knee pain is evaluated.
Scoliosis. Existing scoliosis can progress during rapid growth, so it is monitored, though growth hormone has not been shown to cause more scoliosis.
Pancreatitis. Cases have been reported with somatropin, possibly more in children. It is considered in anyone with persistent severe stomach pain.
Fat loss at injection sites. Injecting in the same spot for a long time can cause lipoatrophy, so sites are rotated weekly.
Sudden death in children with Prader-Willi syndrome. Sudden deaths have been reported after starting somatropin in children with Prader-Willi syndrome who had severe obesity, airway blockage or sleep apnea, or an unidentified respiratory infection. Ngenla is not approved for growth failure from genetically confirmed Prader-Willi syndrome.
Lab tests. Phosphorus, alkaline phosphatase and parathyroid hormone may rise on Ngenla.
Who should not use it. Children with acute critical illness, allergy to somatrogon-ghla or its ingredients, closed growth plates, active cancer, active proliferative or severe non-proliferative diabetic eye disease, or Prader-Willi syndrome with severe obesity or severe breathing problems.
From the Patient Information leaflet that comes with Ngenla:
Dose Track has a side-effect log. Each entry records the symptom, a severity (none, mild, moderate, severe or life-threatening), the date and an optional note, and can be tied to a specific dose or logged on its own. The history screen shows what you logged over time, which makes it easier to tell your prescriber when a reaction started and whether it is easing. The app records what you enter; it does not judge whether a symptom is serious. For anything on the label's call-your-doctor list, call your doctor.
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.