PeptulatorReconstitution and dosing maths

HGH (somatropin) dosage calculator

Growth hormone is the one compound here labelled in IU rather than mg. Enter the IU on your vial, the water you added and your IU dose to get the mark on the syringe.

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Dose to units at the usual vial and water

DoseU-100 unitsDrawDoses per vialVial lasts
1 IU10 units0.1 mL1010 days
2 IU20 units0.2 mL55 days
3 IU30 units0.3 mL33 days
4 IU40 units0.4 mL22 days
5 IU50 units0.5 mL22 days
6 IU60 units0.6 mL11 day

10 IU vial in 1 mL of bacteriostatic water (10 IU/mL), U-100 insulin syringe, once daily.

About HGH (somatropin)

Somatropin is recombinant human growth hormone, a 191 amino acid protein. It is a prescription medicine with licensed uses, and any use outside a prescription is unlicensed. Vials sold as research material are not the licensed product.

The unit confusion here is specific: the vial is labelled in international units (IU), not milligrams, and the syringe is labelled in insulin units. They are unrelated. 1 mg of somatropin is roughly 3 IU. A 10 IU vial reconstituted with 1 mL gives 10 IU per mL, so 2 IU is 0.2 mL, which is 20 units on a U-100 insulin syringe. That 20 has nothing to do with the IU figure; it is a volume.

Growth hormone is fragile once reconstituted. Swirl, never shake, and keep it refrigerated. Reported protocols commonly run 1 to 4 IU per day, often split, but that is a description of what people report and not a recommendation.

The same 10 IU vial at other water volumes

If the draw is awkward to read, change the water, not the dose. The dose stays the same; only the mark moves.

VialBAC waterConcentrationDrawU-100 unitsDoses/vial
10 IU1 mL10 IU/mL0.2 mL20 units5
10 IU2 mL5 IU/mL0.4 mL40 units5
10 IU3 mL3.33 IU/mL0.6 mL60 units5
12 IU1 mL12 IU/mL0.167 mL16.7 units6
12 IU2 mL6 IU/mL0.333 mL33.3 units6
12 IU3 mL4 IU/mL0.5 mL50 units6

All rows above assume a 2 IU dose and a standard U-100 insulin syringe, where 100 units = 1 mL.

How long it lasts in the body

The half-life of HGH (somatropin) is about 3.8 hours. That is the time for the amount in your blood to halve, so after one half-life you are at 50 percent of the peak, after two you are at 25 percent, and after four you are at roughly 6 percent. This is why it is dosed daily or more often: by the next morning almost none of the previous dose is left, and there is no build-up from day to day.

100%75%50%25%0%one half-life0 h3.8 h7.6 h11.4 h15.2 h

Common questions

How many units is 2 IU of HGH (somatropin)?
It depends entirely on how much water you added. In a 10 IU vial reconstituted with 1 mL, the concentration is 10 IU/mL, so 2 IU is 0.2 mL, which is 20 units on a U-100 insulin syringe. In the same vial with 0.5 mL of water it is 10 units, and with 1.5 mL it is 30 units.
How much bacteriostatic water for a 10 IU HGH (somatropin) vial?
1 mL is the usual choice. It gives 10 IU/mL, which puts the commonly reported range of 0.5 IU to 6 IU between roughly 5 and 60 units. Aim for a draw between about 10 and 50 units, where the barrel is easiest to read, and add or remove water to get there.
How many doses are in a 10 IU vial?
Divide 10 by your dose. At 2 IU that is 5 doses, which at once daily is 5 days.
How many units is 2 IU of HGH?
It depends on the water. A 10 IU vial with 1 mL of water is 10 IU/mL, so 2 IU is 0.2 mL, which is 20 units on a U-100 insulin syringe. With 2 mL of water the same 2 IU is 40 units.
How many mg is 10 IU of HGH?
About 3.3 mg. The conversion for somatropin is roughly 3 IU per mg. You do not need it for the calculator, which works in IU throughout.
IndependentThis site does not sell peptides and is not owned by a vendor.
The maths is openThe formula is on every page and in the methodology. The code is one file with an automated test suite, run before each deploy.
How it earnsAffiliate links on one marked page, never inside the calculator.
ReviewedDose ranges and half-lives checked 3 September 2026.

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Tools

Before you use these numbers This is a unit-conversion tool. It turns a vial strength and a water volume into a concentration, a draw volume and a syringe mark. It does not tell you what to take, whether to take it, or whether a compound is safe for you. Most compounds listed are sold for laboratory research and are not approved for human use. Nothing here is medical advice. Dosing decisions belong with a licensed clinician who knows your history. Always check the strength printed on your own vial rather than trusting a preset.