Lab arithmeticSomatropin (HGH 191AA)FDA-approved
Somatropin 10 IU: dosing evidence and reconstitution math
A 10 IU vial of Somatropin mixed with 2 mL of diluent is 5 IU/mL, so 10 units on a U-100 syringe (0.1 mL) contain 0.5 IU.
Is there an established dose?
Doses of the FDA-approved product (NORDITROPIN, NORDITROPIN FLEXPRO, NORDITROPIN NORDIFLEX) are set by its FDA label, linked below; research-grade vials are not that product.
- NORDITROPIN, NORDITROPIN FLEXPRO, NORDITROPIN NORDIFLEX on Drugs@FDA (NOVO NORDISK INC)
- Somatropin (HGH 191AA) profile: FDA status, research volume and registered trials.
10 IU vial concentration table
Concentration = vial content ÷ diluent volume. A U-100 insulin syringe holds 1 mL in 100 units, so 1 unit = 0.01 mL.
| Diluent | Concentration | Per 10 units (0.1 mL) | Per 1 unit |
|---|---|---|---|
| 1 mL | 10 IU/mL | 1 IU | 0.1 IU |
| 2 mL | 5 IU/mL | 0.5 IU | 0.05 IU |
| 3 mL | 3.333 IU/mL | 0.333 IU | 0.033 IU |
| 5 mL | 2 IU/mL | 0.2 IU | 0.02 IU |
Arithmetic only; it assumes the vial contains exactly what the label states. Independent tests often find vials under- or over-filled, which is why a lot's certificate of analysis matters.
Syringe units for a given amount
Units on a U-100 syringe needed to draw each amount from this 10 IU vial, by diluent volume. The amounts are fractions of the vial (1/50, 1/20, 1/10, 1/5), not dose suggestions.
| Amount | 1 mL diluent | 2 mL diluent | 3 mL diluent |
|---|---|---|---|
| 0.2 IU | 2 units | 4 units | 6 units |
| 0.5 IU | 5 units | 10 units | 15 units |
| 1 IU | 10 units | 20 units | 30 units |
| 2 IU | 20 units | 40 units | 60 units |
Units = amount ÷ concentration × 100. Draws above 100 units exceed a 1 mL syringe.
What the research covers
A PubMed search for "somatropin"[tiab] returned 420 records (155 from the last five years), 72 indexed as clinical trials when checked on October 2026.
- Efficacy and Safety of Weekly Somatrogon vs Daily Somatropin in Children With Growth Hormone Deficiency: A Phase 3 Study.
- Somatropin.
- Lonapegsomatropin.
- Somatrem.
- Weekly Lonapegsomatropin in Treatment-Naïve Children With Growth Hormone Deficiency: The Phase 3 heiGHt Trial.
ClinicalTrials.gov lists 818 registered studies (search), including:
Where research vials are listed
5 suppliers in our directory list Somatropin (A–Z): Peptide Worldwide, Peptide.Express, Pure Lab Peptides, Royal Peptides, San Diego Peptides. A listing is not a quality endorsement; ask for a lot-specific certificate of analysis.
Storage & handling
Follow the storage statement on the product sheet or certificate of analysis. Lyophilized (freeze-dried) peptides are generally kept cold, dry and away from light; once reconstituted, stability is shorter and depends on the compound and diluent. Bacteriostatic water contains 0.9% benzyl alcohol as a preservative; sterile water does not.
Frequently asked questions
How much bacteriostatic water for a 10 IU Somatropin vial?
The diluent volume only sets the concentration: 1 mL gives 10 IU/mL, 2 mL gives 5 IU/mL and 3 mL gives 3.333 IU/mL. Smaller volumes are more concentrated, so each syringe unit holds more.
How much Somatropin is in 10 units?
At 2 mL of diluent, 10 units (0.1 mL) of a 10 IU vial contain 0.5 IU; at 1 mL they contain 1 IU.
What is the dose of Somatropin?
Doses of the FDA-approved product (NORDITROPIN, NORDITROPIN FLEXPRO, NORDITROPIN NORDIFLEX) are set by its FDA label, linked below; research-grade vials are not that product.
Related pages
Peptide calculator BAC water calculator Growth hormone & GHRH protocols