Syringe Unit
A syringe unit is a calibration mark on an insulin syringe barrel. On U-100 syringes, 1 unit equals 0.01 mL; on U-40 syringes, 1 unit equals 0.025 mL — different calibrations requiring different dose math.
Overview
Insulin syringes are not calibrated in milliliters directly — they use 'units' as their scale markings. The number of units per milliliter depends on the syringe type: U-100 (100 units/mL) and U-40 (40 units/mL). Most research peptide dosing math assumes a U-100 syringe because it is the most widely available. When converting a volume in mL to units: multiply by 100 for U-100 or by 40 for U-40. Accidentally using U-40 math with a U-100 syringe (or vice versa) leads to significant dosing errors, so identifying syringe type before any calculation is essential. Syringe unit calculators automate this conversion.
Related Terms
Related Calculators
Frequently asked questions
How do I tell if my syringe is U-100 or U-40?+
Check the syringe label or packaging. U-100 syringes are by far the most common in the US. U-40 syringes are used for veterinary insulin and are less common.
Why do syringe units matter for peptide dosing?+
All peptide dose calculations output a volume in mL, which must be converted to syringe units to know how far to draw the plunger. Using the wrong syringe type gives the wrong unit count and therefore the wrong dose.
How many units is 0.1 mL on a U-100 syringe?+
0.1 mL × 100 units/mL = 10 units on a U-100 syringe.