Short answer: In the label's 24-week study of 164 children with growth hormone deficiency, the most common Zomacton side effects were upper respiratory infection (32%), fever (16%), sore throat (12%), headache (11%) and ear infection (10%). The study had no placebo group. In adults, the label describes fluid retention, joint and muscle pain and tingling, usually early and dose dependent. Zomacton has no boxed warning.
What Zomacton is approved for: Zomacton is approved for children with growth failure from growth hormone deficiency, short stature with Turner syndrome, idiopathic short stature (height SDS of -2.25 or below), short stature or growth failure from SHOX deficiency, or short stature after being born small for gestational age with no catch-up growth by 2 to 4 years of age. It is also approved to replace growth hormone in adults with growth hormone deficiency (sections 1.1 and 1.2).
Source
ZOMACTON (somatropin) for injection, for subcutaneous use, prescribing information and Instructions for Use. Ferring Pharmaceuticals. DailyMed, version published August 28, 2026. DailyMed setid 85ba081b-bee0-4a9a-aa0f-ae5b5e9a0886
No. The current Zomacton 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 Zomacton.
| Adverse Reaction | 24 Week Exposure to ZOMACTON (n=164) |
|---|---|
| Upper respiratory infection | 32% |
| Fever | 16% |
| Pharyngitis | 12% |
| Headache | 11% |
| Otitis Media | 10% |
| Increased cough | 9% |
| Abdominal pain | 7% |
| Anemia | 6% |
| Maculopapular rash | 6% |
| Diarrhea | 5% |
| Pain | 5% |
| Rhinitis | 5% |
Open-label study of 164 children aged 2.1 to 17.7 years, with no placebo or untreated group, so these numbers cannot show how much is due to Zomacton itself.
| Adverse Reaction | Placebo (6 Months)/GH (12 Months) (n=46) | 18 Months GH Exposure (n=52) |
|---|---|---|
| Edema | 15% | 21% |
| Arthralgia | 15% | 17% |
| Paresthesia | 13% | 17% |
| Myalgia | 13% | 14% |
| Pain | 13% | 14% |
| Rhinitis | 11% | 14% |
| Peripheral edema | 17% | 12% |
| Back pain | 11% | 10% |
| Headache | 11% | 8% |
| Hypertension | 4% | 8% |
| Acne | 0% | 6% |
| Joint disorder | 2% | 6% |
| Surgical procedure | 2% | 6% |
| Flu syndrome | 7% | 4% |
These adult numbers are from studies of another somatropin product, not Zomacton, as the label states. The first column is 6 months of placebo followed by 12 months of somatropin; the second is 18 months of somatropin. The label marks edema (p=0.04) and peripheral edema (p=0.02) as differing from placebo.
In studies of children with growth hormone deficiency, injection site pain was reported in 1.6%, and a mild, short-lived edema early in treatment in 1.6%. In the 24-week study, 15 children had T4 values that sometimes fell below normal; all but one were normal at the next visit.
Turner syndrome, another somatropin product at 0.3 mg/kg/week vs untreated over 4.7 years (Table 2): surgical procedures 45% vs 27%, ear infections 43% vs 26%, ear disorders 18% vs 5%.
Idiopathic short stature, another somatropin product vs placebo over 4.4 years (Table 3): scoliosis 19% vs 13%, ear infections 16% vs 7%, muscle pain 24% vs 13%, joint pain 11% vs 3%, high blood fats 8% vs 3%.
SHOX deficiency, another somatropin product vs untreated over 2 years (Table 4): joint pain 11% vs 8%, gynecomastia 8% vs 0%, many skin moles 7% vs 0%. At least one IGF-1 level above +2 SD occurred in 37.0% vs 0%.
Adult-onset growth hormone deficiency, first 6 months on another somatropin product vs placebo: edema 17% vs 4% and peripheral edema 12% vs 0%. 2 of 113 adults developed carpal tunnel syndrome after starting maintenance without a low-dose lead-in; it eased after a dose reduction.
In two placebo-controlled trials of 522 critically ill adults in intensive care without growth hormone deficiency, deaths were 42% on somatropin (5.3 mg/day-8 mg/day) vs 19% on placebo.
The Warnings and Precautions part of the label lists these. Each line gives the label's heading and what it means in plain words.
Who should not use it. People with acute critical illness after open heart or abdominal surgery, multiple injuries or acute respiratory failure; children with Prader-Willi syndrome who are severely obese or have airway or severe breathing problems; active cancer; a known allergy to somatropin or its ingredients; active proliferative or severe non-proliferative diabetic eye disease; or children whose growth plates have closed.
Acute critical illness. Higher death rates have been reported in critically ill people given somatropin. Zomacton is not for adults without growth hormone deficiency.
Prader-Willi syndrome in children. 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. Treatment is paused if snoring starts or worsens or sleep apnea appears.
Tumors. Any past cancer should be inactive and treated before starting. 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. Somatropin may lower insulin sensitivity, especially at higher doses, and can unmask glucose intolerance or diabetes. New type 2 diabetes has been reported. Glucose is checked periodically.
Raised pressure in the skull. Intracranial hypertension with optic nerve swelling, vision changes, headache, nausea or vomiting has been reported, usually in the first 8 weeks, and resolved after stopping or lowering the dose. People with Turner syndrome may be at higher risk.
Severe allergic reactions. Anaphylaxis and angioedema have been reported with somatropins after approval. The label says prompt medical attention should be sought if an allergic reaction occurs.
Fluid retention in adults. Swelling, joint pain, muscle pain and nerve compression such as carpal tunnel syndrome or tingling may frequently occur in adults, and are usually temporary and dose dependent.
Cortisol and thyroid. People with or at risk of pituitary hormone deficiencies may develop low cortisol, and those on steroid replacement may need higher doses. Untreated hypothyroidism can blunt the response, and central hypothyroidism may appear or worsen, so thyroid tests are done periodically.
Hips and spine in children. Slipped capital femoral epiphysis, sometimes with bone death, has been reported, so a child with a new limp or hip or knee pain is evaluated. Existing scoliosis can progress during rapid growth.
Pancreatitis. Cases have been reported in children and adults, with risk possibly greater in children and in girls with Turner syndrome. It is considered in anyone who develops stomach pain.
Benzyl alcohol in infants. The diluent that comes with the 5 mg vial contains benzyl alcohol, which can cause serious and fatal reactions ("gasping syndrome") in newborns and infants. For infants, the 5 mg vial is mixed with plain 0.9% sodium chloride instead, one dose per vial.
Injection sites and lab tests. Injecting in the same spot for a long time can cause fat loss, so sites are rotated. Phosphorus, alkaline phosphatase, parathyroid hormone and IGF-1 levels may rise.
From the Patient Counseling Information (section 17) and Instructions for Use that comes with Zomacton:
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.