Understanding HGH Measurement Units
A plain-English guide to mg, mcg, mL, µL and IU, which conversions are simple arithmetic and which depend on the product.
Last updated November 11, 2026
Two kinds of measurement
Reconstitution math involves three kinds of quantities: mass (how much substance), volume (how much liquid) and biological activity (how active the substance is). Mixing them up is the root of most unit errors.
Mass units
| Unit | Symbol | Equals |
|---|---|---|
| Gram | g | 1,000 mg |
| Milligram | mg | 1,000 mcg |
| Microgram | mcg or µg | 0.001 mg |
These are fixed metric relationships. See mg vs mcg explained for common pitfalls.
Volume units
| Unit | Symbol | Equals |
|---|---|---|
| Liter | L | 1,000 mL |
| Milliliter | mL | 1,000 µL |
| Microliter | µL | 0.001 mL |
Biological activity: IU
IU (international unit) measures activity compared with a reference standard. It is not a weight. The link between an IU and a mass is specific to a substance and should be taken from official documentation. Read Understanding International Units.
Concentration units
A concentration combines an amount and a volume: mg/mL, mcg/mL or IU/mL. The unit tells you which kind of amount is being measured, so concentrations in different kinds of units cannot be compared directly.
Practical habits
- Write the unit next to every number.
- Convert to base units (mg and mL) before dividing.
- Multiply the result by the volume to confirm you get the original amount back.
- Compare your numbers with the official label for the product in hand.