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HGH Calculator (IU): Growth Hormone Mixing and Dose

Growth hormone (somatropin) is sold in IU or mg. Enter the vial, the water you add and an amount in IU or mg, and get the units to draw on an insulin syringe.

Worked example: a 10 IU vial with 1 mL of water is 10 IU/mL. 2 IU is 2 ÷ 10 = 0.2 mL, which is 20 units on a U-100 syringe. With 2 mL of water the same 2 IU is 40 units. 1 mg of somatropin is 3 IU (Humatrope label: 6 mg = 18 IU), so a 10 IU vial holds about 3.33 mg. Amounts on this page are examples to show the math, not dose recommendations. How much to take is a decision for you and your prescriber.

Amount in vial

Water added (mL)

Amount per draw

Syringe scale

IU and mg converter (3 IU = 1 mg)

The interactive calculator needs JavaScript. The HGH mixing chart and the IU to mg table below work without it.

Runs entirely in your browser; nothing you type is sent anywhere. Uses 3 IU per mg, as on somatropin labels. Arithmetic, not medical advice.

How the HGH math works

IU and mg: IU = mg × 3, mg = IU ÷ 3
Strength after mixing: IU in vial ÷ mL of water = IU per mL
Volume to draw: IU wanted ÷ IU per mL = mL
Units: mL × 100 on a U-100 insulin syringe

A handy shortcut: with 1 mL of water in a 10 IU vial, every 10 units on the syringe is 1 IU. Double the water and each IU takes twice as many units.

HGH mixing chart: IU per mL and units

Common vial sizes in IU, with 1, 2 or 3 mL of water. The last three columns are U-100 units for 1, 2 and 3 IU, to show the math; they are not doses.

HGH vial (IU), water added, concentration, IU per 10 units, and U-100 units for example amounts of 1, 2 and 3 IU.
Vial	Water	Concentration	Per 10 units	1 IU	2 IU	3 IU
10 IU (3.33 mg)	1 mL	10 IU/mL	1 IU	10	20	30
	2 mL	5 IU/mL	0.5 IU	20	40	60
	3 mL	3.33 IU/mL	0.33 IU	30	60	90
12 IU (4 mg)	1 mL	12 IU/mL	1.2 IU	8.3	16.7	25
	2 mL	6 IU/mL	0.6 IU	16.7	33.3	50
	3 mL	4 IU/mL	0.4 IU	25	50	75
15 IU (5 mg)	1 mL	15 IU/mL	1.5 IU	6.7	13.3	20
	2 mL	7.5 IU/mL	0.75 IU	13.3	26.7	40
	3 mL	5 IU/mL	0.5 IU	20	40	60
24 IU (8 mg)	1 mL	24 IU/mL	2.4 IU	4.2	8.3	12.5
	2 mL	12 IU/mL	1.2 IU	8.3	16.7	25
	3 mL	8 IU/mL	0.8 IU	12.5	25	37.5
36 IU (12 mg)	1 mL	36 IU/mL	3.6 IU	2.8	5.6	8.3
	2 mL	18 IU/mL	1.8 IU	5.6	11.1	16.7
	3 mL	12 IU/mL	1.2 IU	8.3	16.7	25

Scroll the table sideways to see every column.

HGH IU to mg conversion

Somatropin labels pair mg with IU at 3 IU per mg. The Humatrope label lists its cartridges as 6 mg (18 IU), 12 mg (36 IU) and 24 mg (72 IU).

Somatropin IU to mg at 3 IU per mg.
IU	mg	mcg
1 IU	0.333 mg	333 mcg
2 IU	0.667 mg	667 mcg
3 IU	1 mg	1000 mcg
4 IU	1.333 mg	1333 mcg
5 IU	1.667 mg	1667 mcg
6 IU	2 mg	2000 mcg
8 IU	2.667 mg	2667 mcg
10 IU	3.333 mg	3333 mcg
12 IU	4 mg	4000 mcg
15 IU	5 mg	5000 mcg
18 IU	6 mg	6000 mcg
24 IU	8 mg	8000 mcg
30 IU	10 mg	10000 mcg
36 IU	12 mg	12000 mcg

Genotropin and Norditropin pens

Prescription pens are labeled in mg. From the labels: Genotropin comes in 5 mg and 12 mg two-chamber cartridges, plus single-dose MiniQuick devices from 0.2 to 2 mg. Norditropin FlexPro pens are 5 mg/1.5 mL, 10 mg/1.5 mL, 15 mg/1.5 mL and 30 mg/3 mL. At 3 IU per mg, a 5 mg pen holds about 15 IU and a 12 mg cartridge about 36 IU. Pens are used as their own instructions describe, not with an insulin syringe.

More on growth hormone

The HGH guide covers vial sizes and reconstitution, with a worked 10 IU vial page. The HGH half-life chart shows how levels rise and fall after a dose, and missed a somatropin dose covers what the labels say about a missed injection.

Sources

Frequently asked questions

How many mg is 1 IU of HGH?+

About 0.333 mg (333 mcg). Somatropin labels pair the two at 3 IU per mg; the Humatrope label lists 6 mg cartridges as 18 IU, 12 mg as 36 IU and 24 mg as 72 IU. So 3 IU is 1 mg and 10 IU is about 3.33 mg.

How many IU are in a 5 mg or 10 mg vial?+

At 3 IU per mg, 5 mg is 15 IU and 10 mg is 30 IU. A vial sold as 10 IU holds about 3.33 mg, and 36 IU is 12 mg.

How much water do I add to a 10 IU vial of HGH?+

The water only sets the strength. 1 mL in a 10 IU vial gives 10 IU/mL, so every 10 units on a U-100 syringe holds 1 IU. 2 mL gives 5 IU/mL, so 1 IU is 20 units. Follow the mixing instructions that come with your product; the calculator does the math for any volume.

How many units on an insulin syringe is 2 IU of HGH?+

It depends on the strength after mixing. 10 IU in 1 mL: 2 IU is 0.2 mL, or 20 units on a U-100 syringe. 10 IU in 2 mL: 40 units. 36 IU in 3 mL (12 IU/mL): about 16.7 units. Formula: IU ÷ (IU per mL) × 100.

How do I convert an HGH dose in mg to IU?+

Multiply mg by 3. 0.5 mg is 1.5 IU, 1 mg is 3 IU and 2 mg is 6 IU. To go back, divide IU by 3. US prescription labels give doses in mg, often per kg of body weight.

What strengths do Genotropin and Norditropin pens come in?+

From the labels: Genotropin comes in 5 mg and 12 mg two-chamber cartridges, and Genotropin MiniQuick in single doses from 0.2 to 2 mg. Norditropin FlexPro pens are 5 mg/1.5 mL, 10 mg/1.5 mL, 15 mg/1.5 mL and 30 mg/3 mL. These are labeled in mg; at 3 IU per mg a 5 mg pen holds about 15 IU. Use the pen as its instructions describe.

Is this HGH calculator free?+

Yes. It runs in your browser with no account, and nothing you type is sent anywhere. It does arithmetic on the numbers you enter; it is not medical advice.