IU ⇌ MG

HGH IU/mg

Convert between IU and mg — same hormone, different label.

Same amount, different label

HGH IU/mg Converter

Growth hormone gets labelled in international units on one box and milligrams on the next, and the two get compared as though they were interchangeable. They aren't — not without knowing the potency the manufacturer assigned. This converts between them, in both directions, and shows the potency figure it used.

The conventional figure for somatropin is 3 IU per milligram, so a 10 IU vial is roughly 3.33mg and a 4mg pen is roughly 12 IU. That default is editable, because it's a convention rather than a constant, and the number on your box is the one that counts.

Tool — HGH IU / mg converterLive

One fill level, two rulers. Drag it, or edit either amount below — they stay locked to the potency you set.

Amount in IU

Amount in mg

Potency (IU per mg)— IU/mg

3 IU per mg is the usual figure for somatropin. It's a labelling convention, not a constant — use whatever your box states, and both rulers rescale to match.

Know the strength? Work out what to draw with the reconstitution calculator →

Reference table — 3 IU per mg

International units	Milligrams at 3 IU per mg
1 IU	0.33 mg
2 IU	0.67 mg
4 IU	1.33 mg
10 IU	3.33 mg
15 IU	5 mg
30 IU	10 mg
36 IU	12 mg

Read this firstThis tool performs a unit conversion. It is not medical advice and it is not a substitute for guidance from a qualified clinician. Verify every calculation independently before use.

Frequently Asked Questions

No. Three is the common convention for somatropin and it's what most labels assume, but the authoritative figure is whatever the manufacturer printed. If the two disagree, believe the box.

International units measure biological activity and predate reliable mass-based standardisation for these products. Milligrams measure mass. Both survived, so both are printed, and the confusion is now traditional.

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