Insulin syringe sizes as makers and pharmacy references describe them: 0.3, 0.5 and 1 mL barrels, 27 to 31 gauge, 6 to 16 mm needles, and measured dead space.
This page reports what an insulin syringe is, in the terms its makers and the pharmacy and nursing references use: gauge, length, barrel and dead space. It names no vendor and sells nothing; the figures come from a device clearance, two drug labels, a CDC chapter, a nursing textbook and two measurement papers, each dated. Which syringe a particular draw fits is arithmetic, and the page does that arithmetic without choosing for anyone.
Four words carry the whole subject. Gauge is the needle's thickness, on a scale where a higher number is thinner. Length is the needle's length, stated in millimetres or inches. Barrel is the syringe's capacity, and on an insulin syringe it is graduated in units, where one unit is 0.01 mL on the U-100 scale. Dead space is the liquid left in the needle and hub after the plunger is fully pressed, which the scale does not show. The insulin syringe units page covers the scale itself; this page covers the hardware.
Gauge and length, as the clearance lists them
BD's 2019 FDA clearance for its insulin syringe range (510(k) K190054, read 2026-09-18) is the most complete public specification of the standard device: a graduated barrel, plunger rod and permanently attached needle, cleared under 21 CFR 880.5860 as a Class II piston syringe and "intended for subcutaneous injection of U-100 insulins". The combinations it lists:
| Barrel |
Gauges listed |
Lengths listed |
| 0.3 mL |
29, 30, 31 gauge |
6 mm, 8 mm, 12.7 mm |
| 0.5 mL |
28, 29, 30, 31 gauge |
6 mm, 8 mm, 12.7 mm |
| 1 mL |
27, 28, 29, 30, 31 gauge |
6 mm, 8 mm, 12.7 mm, 16 mm |
In inches: 6 mm is about 15/64, 8 mm is 5/16, 12.7 mm is 1/2, 16 mm is 5/8. Thirty-one gauge is the thinnest in the range and appears on every barrel at 6 and 8 mm; 27 gauge appears only on the 1 mL barrel at 16 mm.
On length, the references converge from different directions. The FITTER recommendations (Frid et al., Mayo Clinic Proceedings 2016, PMID 27594187), the consensus of 183 diabetes experts from 54 countries, state that the shortest needles, currently 4 mm pen and 6 mm syringe needles, are safe, effective and less painful and are the first-line choice in all patient categories, and that intramuscular injection is to be avoided. CDC's Pink Book chapter 6 (reviewed 2024-04-08), written for vaccines given with a separate needle, gives 5/8 inch at 23 to 25 gauge and a 45-degree angle into pinched skin. Nursing Skills, 2nd edition (Open RN), gives 25 to 31 gauge and half to five-eighths of an inch, at 90 degrees for normal-sized or obese adults and 45 degrees for thin patients. A longer needle at 45 degrees and a short needle at 90 degrees reach the same layer; that is the reconciliation.
Barrel size and the unit scale
The barrels differ in capacity and in the fineness of their lines (K190054, read 2026-09-18).
| Barrel |
Capacity |
Graduation |
Finest volume shown |
Fits a draw of |
| 0.3 mL |
30 units |
1-unit, or half-unit models |
0.01 mL, or 0.005 mL |
up to 30 units |
| 0.5 mL |
50 units |
1-unit |
0.01 mL |
up to 50 units |
| 1 mL |
100 units |
2-unit |
0.02 mL |
up to 100 units |
Two consequences follow. A draw larger than a barrel's capacity needs the next barrel or two syringes: 60 units does not fit a 0.5 mL barrel. A small draw reads more precisely on a finer scale: a 5-unit draw is a labelled line on a half-unit 0.3 mL barrel and falls between two lines on a 1 mL barrel, where the 2-unit step is 40% of the dose. Nursing Skills caps a subcutaneous injection at 1 mL for adults, which is the largest insulin barrel. The drug labels that mention syringes give one worked example between them: MOUNJARO and ZEPBOUND (revised 08/2026 and 8/2026) tell vial users to use a syringe capable of measuring a 0.5 mL or 0.6 mL dose, 50 or 60 units, and a new syringe and needle for each injection.
Dead space, measured
Zule et al. measured the dead space in 56 needle-and-syringe combinations collected from needle and syringe programmes across 17 countries in Europe and Asia (Harm Reduction Journal 2018, PMID 29334973). Barrels ran from 0.5 to 20 mL and needles from 8 to 38 mm. The averages:
| Design |
Average dead space |
| Low-dead-space syringe, permanently attached needle |
3 microlitres |
| High-dead-space syringe with a low-dead-space detachable needle |
13 microlitres |
| Low-dead-space syringe with a high-dead-space detachable needle |
45 microlitres |
| High-dead-space syringe with a high-dead-space detachable needle |
99 microlitres |
The fixed-needle insulin syringe is the first row; a 2018 paper by the same authors records that the World Health Organization recommended in 2012 that needle and syringe programmes offer low-dead-space insulin syringes with permanently attached needles (PMID 30170604). The arithmetic that turns microlitres into peptide: at 5 mg/mL, 3 microlitres holds 15 mcg and 99 microlitres holds about 500 mcg; at 2.5 mg/mL, half those figures. Against a 100 mcg draw, a 99-microlitre dead space is five times the quantity; against a 5 mg draw it is a tenth. The scale on the barrel shows none of it, because the graduations measure the liquid between the plunger tip and the zero line.
What the labels specify
Two kinds of label speak to syringes. The EGRIFTA SV kit (tesamorelin, revised 2/2024, read 2026-09-18) is the labelled peptide closest to a research vial in its handling: it ships 60 sterile 20-gauge 1-inch needles for mixing and 30 sterile 30-gauge half-inch needles for injecting, and states the dose as 0.35 mL of the reconstituted solution. Two needle sizes for two jobs, a thick one to move diluent and a thin one to inject, is the pattern the label sets out. The MOUNJARO and ZEPBOUND labels, whose vials hold a ready solution, specify only the syringe's measuring range and the single-use rule. No research compound has a label, so none has a specified syringe.
Choosing by dose volume: the arithmetic
The draw in units is the quantity in milligrams divided by the concentration in mg/mL, times 100. That number decides the barrel: under 30 units fits every barrel and reads finest on the 0.3 mL; 30 to 50 needs the 0.5 mL or 1 mL; 50 to 100 needs the 1 mL; over 100 needs two syringes or a higher concentration. The concentration is set at reconstitution, which is why the per-compound pages under the reconstitution hub work each vial size at 1, 2 and 3 mL of water, and why the reconstitution calculator returns units alongside mg/mL. The general reconstitution procedure and the supplies around it are Medibact's topic, on its page on how to reconstitute peptides.
What this page does not cover
It does not say where to buy a syringe, what one costs or what any state's law says about buying them; Peptifact's insulin syringes for peptide research page covers the markings, the law and the prices. It does not compare brands, because the clearance and the papers above describe designs, not brands.
Related pages
The insulin syringe units page covers U-100, U-40 and the reading of the scale; the how peptides are injected page reports the procedure as labels and nursing references describe it; the reconstitution hub and dosage hub hold the per-compound arithmetic and the reported ranges.
This page does not recommend a syringe, a needle, a barrel or a dose. It reports what one device clearance, two labels, a CDC chapter, a nursing textbook and two measurement papers state, each with its date, and it does the arithmetic that connects a draw to a barrel.
Sources and dates
Opened 2026-09-18: FDA 510(k) summary K190054, BD Insulin Syringes (regulation, class, barrel sizes, gauges, cannula lengths, graduation steps, indications for use); the EGRIFTA SV label on DailyMed (revised 2/2024, setid 3d783378-b02d-4f19-99dd-0fc91a042224) for the kit contents and dose volume; the MOUNJARO prescribing information (revised 08/2026) and the ZEPBOUND label (revised 8/2026, setid 487cd7e7-434c-4925-99fa-aa80b1cc776b) for the vial-syringe wording; CDC Pink Book chapter 6 (reviewed 2024-04-08); Nursing Skills, 2nd edition, chapter 18 (Open RN, NCBI Bookshelf NBK596739); Frid et al. 2016 (PMID 27594187), Zule et al. 2018 (PMID 29334973) and Zule et al. 2018 (PMID 30170604), abstracts via the NCBI E-utilities. Corrections go to the contact page.
