Understanding Insulin Syringe Units: U-100 vs U-40 Explained
Learn the difference between U-100 and U-40 insulin syringes, how to read unit markings, and how to convert between units and milliliters for peptide dosing.
Why Unit Labels Cause Confusion
Syringe units are scale markers, not universal volume values. The same number of units can mean different milliliters depending on syringe calibration.
U-100 Basics
- 100 units equals 1 mL
- 1 unit equals 0.01 mL
- Most peptide calculators assume U-100 by default
U-40 Basics
- 40 units equals 1 mL
- 1 unit equals 0.025 mL
- Each U-40 unit is 2.5x the volume of a U-100 unit
Quick Conversion Table
| Volume (mL) | U-100 Units | U-40 Units |
|---|---|---|
| 0.05 | 5 | 2 |
| 0.10 | 10 | 4 |
| 0.25 | 25 | 10 |
| 0.50 | 50 | 20 |
| 1.00 | 100 | 40 |
Safe Interpretation Rule
If a protocol says "inject 10 units," always confirm syringe type first.
- 10 units on U-100 is 0.10 mL
- 10 units on U-40 is 0.25 mL
Choosing a Syringe
- Match your syringe to your protocol assumptions.
- Use one syringe standard consistently.
- Convert and verify before every change in concentration.
Use the dosage calculator to display both mL and unit values for the same dose.
Calculate Your Dose →
For research and informational purposes only. This is not medical advice.
Not FDA-approved for human use. Consult a qualified healthcare provider
before using any peptide.