Zomacton Vial Sizes and Doses
Zomacton (somatropin) comes in two main vial sizes for reconstitution: 5 mg and 10 mg. Each provides a specific number of doses based on the supplied diluent and standard dosing practices.
5 mg vial: Contains 5 mg of somatropin. Reconstituted with 1.5 mL bacteriostatic water, it yields ~3.33 mg/mL. This typically delivers 10 doses of 0.5 mg (0.15 mL each) or fewer doses at higher strengths like 1 mg.[1][2]
10 mg vial: Contains 10 mg of somatropin. Reconstituted with 3 mL bacteriostatic water, it yields ~3.33 mg/mL. This provides 20 doses of 0.5 mg (0.15 mL each) or 10 doses of 1 mg (0.3 mL each).[1][2]
Doses depend on patient weight (e.g., 0.16–0.24 mg/kg/week, divided daily) and pen injector use post-reconstitution. Unused portions last up to 28 days refrigerated.[1]
How Dosing Works in Practice
Subcutaneous injection volumes are small (0.1–0.5 mL). For a 20 kg child at 0.18 mg/kg/week (~0.5 mg/day), the 10 mg vial covers ~20 days. Providers adjust based on growth response and IGF-1 levels.[1][3]
Storage After Mixing
Reconstituted vials stay stable for 28 days at 2–8°C. Discard if cloudy or past expiry. Multi-dose format reduces waste vs. single-use cartridges.[1]
Compared to Other Growth Hormone Brands
| Brand | Vial Size | Doses at 0.5 mg | Notes |
|-------|-----------|-----------------|-------|
| Zomacton | 10 mg | 20 | Cheaper multi-dose[2] |
| Norditropin | Prefilled pens | Varies | No reconstitution[4] |
| Genotropin | 5.3/12 mg | 8–24 | MiniQuick single-use option[5] |
Zomacton vials suit cost-conscious users; pens like Humatrope offer convenience but higher cost.[2][4]
[1]: Zomacton Prescribing Information (FDA)
[2]: Drugs.com - Zomacton Dosing
[3]: Ferring Pharmaceuticals Product Insert
[4]: Novo Nordisk - Norditropin
[5]: Pfizer - Genotropin