Human Growth Hormone reconstitution calculator.
A 5 mg vial of Human Growth Hormone dissolved in 2 mL of bacteriostatic water is 2,500 mcg per mL, which is 25 mcg per unit on a U-100 insulin syringe.
Human growth hormone is written about in two different units: mass in mg, and biological activity in international units (IU). The WHO standard for somatropin sets 3 IU per mg, so a 5 mg vial is 15 IU and a 10 mg vial is 30 IU, but this calculator works in mass, so an IU figure has to become mg before it goes in. Approved somatropin comes as pens, cartridges and vials with a labeled strength and their own instructions, and where you have one of those, the labeling governs.
Each unit on a 100u · 1.0 mL syringe ≈ 25 mcg of this solution.
Show the math
More water → lower concentration → more units for the same amount.
How much bacteriostatic water for a Human Growth Hormone vial?
There is no single correct volume. More water gives a weaker solution, so each unit on the syringe holds less Human Growth Hormone and a given amount takes more units to measure, which is easier to read on the syringe scale. Less water does the opposite. These tables show the concentration for each common vial size across the usual volumes. They are arithmetic, not a recommendation of how much to take.
| BAC water | Concentration | Per 1 unit | Per 10 units |
|---|---|---|---|
| 1 mL | 5,000 mcg/mL | 50 mcg | 500 mcg |
| 1.5 mL | 3,333 mcg/mL | 33.3 mcg | 333 mcg |
| 2 mL | 2,500 mcg/mL | 25 mcg | 250 mcg |
| 2.5 mL | 2,000 mcg/mL | 20 mcg | 200 mcg |
| 3 mL | 1,667 mcg/mL | 16.7 mcg | 167 mcg |
| BAC water | Concentration | Per 1 unit | Per 10 units |
|---|---|---|---|
| 1 mL | 10,000 mcg/mL | 100 mcg | 1,000 mcg |
| 1.5 mL | 6,667 mcg/mL | 66.7 mcg | 667 mcg |
| 2 mL | 5,000 mcg/mL | 50 mcg | 500 mcg |
| 2.5 mL | 4,000 mcg/mL | 40 mcg | 400 mcg |
| 3 mL | 3,333 mcg/mL | 33.3 mcg | 333 mcg |
How many units of Human Growth Hormone is a given amount?
Divide the amount in micrograms by the micrograms per unit for your mix. With a solution of 2,500 mcg per mL, one unit on a U-100 syringe holds 25 mcg, so any amount in mcg divided by 25 gives the units. The calculator above does this for you from your own vial and water, and the tables give the per-unit figure for each common mix.
Why does Human Growth Hormone need its own calculation?
- Syringe units and IU are unrelated. A U-100 unit is 0.01 mL of liquid; an IU is an amount of hormone activity. How many IU a syringe unit carries depends entirely on your concentration.
- At 3 IU per mg, 1 IU is about 333 mcg. A 5 mg vial in 1.5 mL is 10 IU/mL, so each U-100 unit holds 0.1 IU, about 33 mcg, which is why that volume turns IU figures into round unit counts.
- Approved products state their strength on the label, in mg and often in IU as well, and many are pens or cartridges whose concentration is fixed by the manufacturer. Those are read from the label and instructions for use, not computed here.
- The 3 IU per mg ratio belongs to somatropin. It does not apply to HGH fragment 176-191, AOD-9604, or secretagogues such as ipamorelin and sermorelin, which are measured by mass only.
How is Human Growth Hormone administered, and what does the math look like?
How Human Growth Hormone is actually administered, with the concentration arithmetic written out. Amounts in these tables are illustrative examples of the math, never a recommendation.
Human Growth Hormone: research formats
Choose the format you are researching to see route-specific notes.
Approved only when prescribed for specific GH deficiency diagnoses; compounded HGH is illegal.
FDA-approved somatropin (Norditropin, Genotropin, Humatrope, others) is sold as lyophilized powder in vials or prefilled cartridges, labelled in milligrams. The current WHO reference standard puts somatropin at about 3 IU per mg, so a 5 mg presentation is roughly 15 IU. Reconstituted with the supplied diluent. Only the approved branded products are legal in the US; compounded or imported HGH is not approved.
Human Growth Hormone reconstitution: common questions
How many IU are in a 10 mg HGH vial?
30 IU at the WHO ratio of 3 IU per mg, and 15 IU in a 5 mg vial. If your product's label states a different ratio or an IU figure directly, the label is the number to use. The mg to IU converter does this step with an editable ratio.
How many units is 1 IU of HGH?
Convert to mass first: 1 IU is about 333 mcg at 3 IU per mg. On a 5 mg vial in 1.5 mL (10 IU/mL) that is 10 units. On the same vial in 2 mL (7.5 IU/mL) it is about 13.3 units. Enter the mg figure above to see it for your own vial.
Why do different sources give different IU per mg figures?
An IU is a unit of biological activity defined against a reference standard, not a unit of mass, so the ratio depends on the standard used. The WHO standard for somatropin sets 3 IU per mg, which is the default in the site's converter, and the ratio stays editable because the figure printed on your product's label is the one that governs it.
What the evidence on Human Growth Hormone actually shows
Knowing the concentration is not the same as knowing whether to use it. These are the strongest studies behind the Human Growth Hormone profile, labelled with the study type PubMed itself assigns.
- Systematic review / meta-analysis · 2010Recombinant human growth hormone for the treatment of growth disorders in children: a systematic review and economic evaluationHealth technology assessment (Winchester, England) · PMID 20849734
- Systematic review / meta-analysis · 2007Systematic review: the safety and efficacy of growth hormone in the healthy elderlyAnnals of internal medicine · PMID 17227934
- Randomized controlled trial · 2020Once-weekly Somapacitan is Effective and Well Tolerated in Adults with GH Deficiency: A Randomized Phase 3 TrialThe Journal of clinical endocrinology and metabolism · PMID 32022863
This page is arithmetic on numbers you enter. It does not recommend an amount of Human Growth Hormone, and nothing here is medical advice. For what the published evidence actually supports, read the Human Growth Hormone profile, and for regulatory status see is Human Growth Hormone legal. Reviewed June 1, 2026.
Different question? The general reconstitution calculator covers every compound on the site, the blend calculator handles multi-peptide stacks, and vial longevity turns a vial into weeks of supply.
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