Vial Guide

Somatropin (HGH) 24 IU vial

How much bacteriostatic water to add to a 24 IU vial of Somatropin (HGH), the syringe units for each common dose, and how many doses the vial holds.

Water
2 mL
Strength
12 IU/mL
Common dose
2 IU
Draw
16.7 units0.17 mL
Doses per vial
12

The short answer

Mixed with 2 mL of bacteriostatic water, a 24 IU vial of Somatropin (HGH) holds 12 IU/mL. A 2 IU dose is then 16.7 units (0.17 mL) on a U-100 insulin syringe, and the vial holds about 12 doses of that size. Taken 1× per day, it lasts about 12 days.

Approved drug. FDA-approved since 1987 as daily injections for adults with growth hormone deficiency and several growth disorders in children, and as Serostim for HIV-associated wasting. Weekly long-acting versions (somapacitan, somatrogon, lonapegsomatropin) are different molecules. In healthy young adults, trials found more lean mass, much of it water, but no gain in strength.
Somatropin (HGH) page

How much water

The water only sets the strength; the dose and the number of doses in the vial stay the same. Draws are on a U-100 insulin syringe, where 1 unit is 0.01 mL.

Water addedStrengthPer syringe unitDraw for 2 IU
1 mL24 IU/mL0.2 IU8.3 units (0.083 mL)
2 mL12 IU/mL0.1 IU16.7 units (0.17 mL)
3 mL8 IU/mL0.1 IU25 units (0.25 mL)

Dose chart

Syringe units for each common dose at each water volume. Select a cell to open it in the calculator.

DoseWater added
1 mL2 mL3 mL
0.5 IU
0.6 IU
1 IU
1.5 IU
2 IU
3 IU
4 IU

Draws over 100 units show in mL. Faded values are under 2 units, which is hard to measure. Check that your vial holds the larger volumes.

Where the doses come from

  • Label Adults with growth hormone deficiency: start about 0.2 mg a day (range 0.15–0.3 mg, roughly 0.5–1 IU), raised every 1–2 months by 0.1–0.2 mg according to IGF-1 and side effects. EU labels say maintenance rarely exceeds 1 mg (3 IU) a day.
  • Label HIV-associated wasting: about 0.1 mg/kg once daily at bedtime, up to 6 mg (about 18 IU), with HIV treatment. Every other day is an option when side effects are a concern.
  • Community Research vials: commonly 2 IU, up to about 4 IU, once a day under the skin, often at bedtime, in courses of 12 weeks or longer. 2–4 IU is about 0.7–1.3 mg, around or above the top of adult replacement doses.

Doses are what labels, trials or community reports reference, not recommendations. Somatropin (HGH)’s page has the cycle, side effects, cautions and sources.

Mixing and storage

  1. PrepareLet a refrigerated vial come to room temperature, and wipe both stoppers with an alcohol swab.
  2. Add 2 mLDraw 2 mL of bacteriostatic water and let it run slowly down the inside wall of the vial.
  3. Swirl, don’t shakeSwirl gently until the powder dissolves and the liquid is clear.
  4. Label itWrite the date and the strength, 12 IU/mL, on the vial.

Storage: Research vials, mixed: 2–8 °C. Approved pens, cartridges and vials: fridge, then 14–28 days once mixed or in use, depending on the product (Norditropin: up to 3 weeks at 25 °C).

The reconstitution guide covers each step, and the units page explains syringe markings.

Questions

How much water do I add to a 24 IU vial of somatropin (HGH)?

There’s no single right amount: the water only sets the strength. With 2 mL of bacteriostatic water, a 24 IU vial holds 12 IU/mL. With 1 mL it’s 24 IU/mL; with 3 mL it’s 8 IU/mL. Less liquid makes each dose a smaller draw; more makes small doses easier to measure.

How many units is 2 IU of somatropin (HGH)?

With 2 mL in a 24 IU vial, 2 IU is 16.7 units (0.17 mL) on a U-100 insulin syringe. With 1 mL, 8.3 units (0.083 mL); with 3 mL, 25 units (0.25 mL).

How many doses are in a 24 IU vial of somatropin (HGH)?

About 12 doses of 2 IU, or 8 of 3 IU or 6 of 4 IU. Taken 1× per day at 2 IU, it lasts about 12 days.

How long does a mixed vial of somatropin (HGH) keep?

Research vials, mixed: 2–8 °C. Approved pens, cartridges and vials: fridge, then 14–28 days once mixed or in use, depending on the product (Norditropin: up to 3 weeks at 25 °C).

Other vial sizes

Sources

  • Genotropin prescribing information, rev. 08/2026 (Pfizer, DailyMed)
  • Humatrope (rev. 08/2026), Norditropin (rev. 07/2025), Omnitrope (rev. 07/2025) and Zomacton (rev. 04/2026) prescribing information (DailyMed)
  • Serostim prescribing information, rev. 09/2026 (EMD Serono, DailyMed)
  • Zorbtive (somatropin) label, December 2003 (FDA)
  • Omnitrope EU product information (EMA, 2026)
  • Liu et al., growth hormone and athletic performance, systematic review (Ann Intern Med 2008) PMID 18347346
  • Hazem et al., GH therapy in adults with GH deficiency, meta-analysis (Eur J Endocrinol 2012) PMID 21865409

The math on this page uses the doses and storage on Somatropin (HGH)’s page.

By Vial Guide editorsLast reviewed

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