What is HGH (somatropin)?
An HGH calculator in IU exists because growth hormone is one of the few products in this space labeled in international units rather than milligrams. If you have a vial marked in IU and want to know how many syringe units match an IU amount, this page does that conversion without asking you to switch to mg first.
Human growth hormone is a protein hormone made by the pituitary gland. Its drug form is somatropin: recombinant human growth hormone with the same amino acid sequence as the natural hormone, a single chain of 191 amino acids. That is where the “HGH 191AA” wording on many research-labeled vials comes from; it is a claim about the sequence, not a brand or a grade.
Because it is a full protein rather than a short peptide, HGH is more sensitive to rough handling than most compounds in the peptide library, and labels tend to say more about mixing and storage.
How much BAC water for an HGH vial?
The water volume only sets the concentration. In IU terms, IU per mL equals vial IU divided by water mL, and each U-100 unit holds one hundredth of that. The chart below shows IU per unit for the vial sizes most often listed: 10 IU, 24 IU and 36 IU.
| BAC water | 10 IU vial | 24 IU vial | 36 IU vial |
|---|---|---|---|
| 1 mL | 0.1 IU/unit 10 IU/mL | 0.24 IU/unit 24 IU/mL | 0.36 IU/unit 36 IU/mL |
| 2 mL | 0.05 IU/unit 5 IU/mL | 0.12 IU/unit 12 IU/mL | 0.18 IU/unit 18 IU/mL |
| 3 mL | 0.03 IU/unit 3.333 IU/mL | 0.08 IU/unit 8 IU/mL | 0.12 IU/unit 12 IU/mL |
Each cell shows IU per unit on a U-100 syringe (100 units = 1 mL) and the resulting concentration.
Read down a column to see how extra water dilutes one vial, or across a row to compare vial sizes at the same volume. Approved somatropin products specify their own diluent and volume, and several are prefilled pens or cartridges that are never mixed by the user at all. For research-labeled vials, the product labeling decides the volume. The BAC water to peptide ratio guide explains the same logic in mg.
HGH 10iu and 36iu: worked examples
The IU math has three steps: IU per mL equals vial IU divided by water mL; volume equals the IU amount divided by IU per mL; units equal mL multiplied by 100. Here is an HGH 10iu vial, for example, if the amount you already have is written down in IU:
The math: 10 IU ÷ 1 mL = 10 IU/mL, which is 0.1 IU per unit. 1.5 IU ÷ 10 IU/mL = 0.15 mL = 15 units on a U-100 syringe.
And the same amount from an HGH 36iu vial mixed with more water:
The math: 36 IU ÷ 3 mL = 12 IU/mL, which is 0.12 IU per unit. 1.5 IU ÷ 12 IU/mL = 0.125 mL = 12.5 units on a U-100 syringe.
The same IU amount lands on a different syringe mark because the concentration changed, not because the amount did. U-100 units are the same size on every U-100 syringe; see the U-100 syringe units to mL chart for capacities.
HGH IU calculator: what the numbers mean
An HGH reconstitution calculator in IU is a unit converter. It takes an IU amount you already have, from product labeling, a document you are reviewing, or a qualified professional, and shows the mL and syringe units for your vial and water volume. It does not decide whether that amount is appropriate, how often it applies, or for whom.
Enter the vial IU exactly as printed, the water volume you are checking, and your amount. If the label lists both mg and IU, use the IU figure so the calculator and the label speak the same unit. The guide to checking calculator math by hand walks through verifying any result.
HGH IU to mg: the conversion people ask about
The commonly cited conversion for somatropin is 1 mg ≈ 3 IU. Approved products often print both figures on the label, which is where the approximation comes from. It is an approximation, not a law of arithmetic, and it applies to somatropin only; do not carry it over to any other compound.
This HGH IU calculator avoids the conversion entirely by working in IU from start to finish. Problems usually start when a vial is labeled in one unit and an amount is written in the other. If you must convert, do it once, write both numbers on your notes, and keep every later step in the same unit. The mg to mcg conversion guide covers the metric side of unit switching.
Reconstitution notes for HGH vials
Labels for somatropin products and research vials tend to be more specific than peptide labels. Some specify sterile water, some specify bacteriostatic water, and approved products name the exact diluent supplied with them. Many labels specify injecting the diluent slowly against the vial wall and swirling gently rather than shaking, because agitation can damage a protein. Refrigeration requirements before and after mixing vary by product and are printed on the label.
Which diluent applies is a labeling question, not a calculator one; the comparison of bacteriostatic and sterile water explains how the two differ. Handling and administration belong to the product labeling and a qualified professional.
Is HGH FDA-approved?
Somatropin is. Recombinant somatropin products such as Genotropin and Norditropin are FDA-approved prescription drugs with full labeling. Research-labeled “HGH” or “HGH 191AA” vials sold online are not those approved products, and a label claim cannot confirm what a vial actually contains, its potency in IU, or its sterility. The math on this page is only as good as the number printed on the vial.
HGH (somatropin) FAQ
What does 191AA mean on an HGH vial?
It refers to the 191-amino-acid sequence of human growth hormone, the same sequence as somatropin. It is a label claim about the molecule, not a brand, grade or proof of content.
How many IU are in 1 mg of HGH?
The commonly cited conversion for somatropin is about 3 IU per mg. It is an approximation; the IU figure printed on the vial label is the one to use in the calculator.
How much BAC water goes in a 10 IU HGH vial?
The calculator does not choose a volume. The chart shows IU per unit for common water volumes; the product labeling decides the diluent and the volume.
Does this HGH calculator give a dose?
No. It converts an IU amount you already have into mL and U-100 syringe units. It does not recommend an amount, a schedule or a use.
Are research HGH vials the same as Genotropin or Norditropin?
No. Those are FDA-approved somatropin products with official labeling. Research-labeled vials sold online are separate products whose content cannot be confirmed by the label alone.