How to read an insulin syringe
A U-100 insulin syringe is marked in insulin units: 100 units per mL. A 0.3 mL barrel reads to 30 units and a 0.5 mL barrel to 50. The 1 mL barrel tops out at 100.
| Product or scale | Capacity | Graduation or concentration | Needle or identifying detail |
|---|---|---|---|
| U-100 insulin scale | 1 mL basis | 100 units per mL | DailyMed HUMULIN R label states a syringe marked for U-100 insulin preparations should always be used |
| U-40 insulin scale | 1 mL = 1 cc | 40 units per mL | DailyMed VETSULIN label states that a syringe other than U-40 gives incorrect dosing |
| embecta Ultra-Fine insulin syringes | 1 mL, 0.5 mL, 0.3 mL | 1/2-unit scale marking available on the 0.3 mL barrel | 6 mm, 8 mm, and 12.7 mm needles; 6 mm needle listed as 31G |
| UltiCare U-100 insulin syringes | 0.3 mL, 0.5 mL, 1.0 mL | 0.3 mL and 0.5 mL barrels graduated in 1-unit increments; 1.0 mL barrel graduated in 2-unit increments | 31G at 6 mm and 8 mm; 30G at 8 mm and 12.7 mm; 29G and 28G at 12.7 mm |
| UltiCare U-100 half-unit product 91007 | 3/10 mL/cc | Half-unit dose markings | 31G x 6 mm needle; quantity 100 |
| McKesson Brand 102-SN310C31516P | 0.3 mL | U-100 insulin / 0.01 mL increments | 31 Gauge x 5/16 inch; McKesson #942674 |
| McKesson Brand 102-SN05C31516P | 0.5 mL | U-100 insulin / 0.01 mL increments | 31 Gauge x 5/16 inch; McKesson #942668 |
| McKesson Brand 102-SN1C31516P | 1 mL | U-100 insulin / 0.01 mL increments | 31 Gauge x 5/16 inch; McKesson #938700 |
How to read U-100 insulin syringe units
The concentration marking separates near-identical syringes. DailyMed’s HUMULIN R label defines U-100 as 100 units per mL and states that a U-100 insulin syringe should always be used with that U-100 preparation. DailyMed’s VETSULIN label runs on a different scale: U-40 insulin contains 40 units per mL, with 1 mL equal to 1 cc. The same 1 mL of volume is a different number of units on each scale.
Barrel size alone does not set the graduation interval. UltiCare’s U-100 line runs 1-unit increments on the 0.3 mL and 0.5 mL barrels; the 1.0 mL barrel is graduated in 2-unit increments. McKesson’s house-brand listings state 0.01 mL increments on the 0.3 mL and 0.5 mL barrels, and the same on the 1 mL. Half-unit scales exist too. embecta lists a 1/2-unit scale marking on its 0.3 mL barrel, and UltiCare’s 3/10 mL/cc product 91007 carries half-unit dose markings.
Needle specs are separate from the scale markings. embecta’s Ultra-Fine syringes carry 6 mm, 8 mm, and 12.7 mm needle lengths, and its U-500 syringe is identified separately by a green U-500 symbol. EXELINT’s U-100 catalog runs from 0.3 mL to 1 mL, including a 1/2 mL line, but its listings do not state graduation intervals.
Where to buy
We do not link retail listings for these insulin syringes.
Sources
- DailyMed — HUMULIN R insulin human injection label
- DailyMed — VETSULIN insulin pork injection label
- embecta — Insulin Syringes with Ultra-Fine needle
- embecta — Micro-Fine Insulin Syringe Portfolio
- UltiMed — UltiCare U-100 Insulin Syringes
- UltiMed — UltiCare U-100 3/10 mL/cc half-unit product 91007
- EXELINT International — Insulin Syringes
- McKesson Medical-Surgical — McKesson Brand 102-SN310C31516P
- McKesson Medical-Surgical — McKesson Brand 102-SN05C31516P
- McKesson Medical-Surgical — McKesson Brand 102-SN1C31516P
Specifications last verified: 2026-07-31