Peptifact

Insulin Syringes for Peptide Research: What the Markings Mean, What the Law Says, What They Cost

A documentary guide to the U-100 insulin syringe: how the unit scale relates to millilitres, what gauge and length numbers mean, the FDA device class, which states sell them without a prescription, and observed prices on 2026-09-05.

Peptifact Editorial · Published 2026-09-05

Research-peptide vendors sell insulin syringes next to bacteriostatic water, and FDA has cited that pairing as evidence of intended human use in its warning letters (USApeptide.com's letter names "Insulin Syringes (10-pack assorted sizes)"). This page is not about how anyone uses a syringe. It is about what the object is: what the numbers on the package mean, what FDA classifies it as, which state law governs buying one, what CDC says about single use, and what a box costs on a given day. Everything here is documentary, and every figure links to where it was read on 2026-09-05.

Rankings on Peptifact follow the published criteria and are never sold; how brands appear on this site is set out on our disclosure page. No product on this page is ranked, because none has been through our testing protocol; the table reports specifications, not scores.

What the device is

FDA classifies the insulin syringe as a piston syringe under 21 CFR 880.5860: "a device intended for medical purposes that consists of a calibrated hollow barrel and a movable plunger", with a male connector for a hypodermic needle, used "to inject fluids into, or withdraw fluids from, the body". It is Class II, subject to performance standards. Manufacturers clear each range through a 510(k) submission; BD's 2019 summary for its BD Insulin Syringe range, K190054, describes the products as "sterile, single use, and non-pyrogenic" and lists the combinations it clears:

Barrel Cannula length Gauge
0.3 mL 12.7 mm 29 G, 30 G
0.3 mL 8 mm 29 G, 31 G
0.3 mL 6 mm 31 G
0.5 mL 12.7 mm 28 G, 29 G, 30 G
0.5 mL 8 mm 31 G
0.5 mL 6 mm 31 G
1 mL 16 mm 27 G
1 mL 12.7 mm 28 G, 29 G, 30 G
1 mL 8 mm 30 G, 31 G
1 mL 6 mm 31 G

Other manufacturers clear their own ranges through the same route, with the same regulation number on the summary; a 510(k) number on a retail page can be looked up in FDA's database to confirm the device is cleared.

Reading the numbers

Units and millilitres. A U-100 insulin syringe is graduated in insulin units because it was designed for U-100 insulin, which contains 100 units per millilitre. The marks are therefore a volume scale under another name: 100 units is 1 mL, 50 units is 0.5 mL, 10 units is 0.1 mL, 1 unit is 0.01 mL. A 0.3 mL syringe is marked to 30 units, a 0.5 mL syringe to 50, a 1 mL syringe to 100. The scale measures the same volume whatever liquid is in the barrel; it says nothing about the concentration of that liquid, which is a separate calculation that belongs to whoever prepared the solution. Syringes marked for U-40 or U-500 insulin use different scales and are labeled as such; the scale printed on the barrel is the thing to read.

Gauge. The gauge number describes the outside diameter of the needle on a scale where a higher number is thinner. BD's cleared range runs from 27 G to 31 G; 31 G is the thinnest in it.

Length. Stated in millimetres or inches: 6 mm (about 15/64 inch), 8 mm (5/16 inch), 12.7 mm (1/2 inch), 16 mm (5/8 inch). Retail listings mix the two systems, so "31G 5/16" and "31G x 8mm" describe the same needle.

Dead space. The volume left in the hub and needle after the plunger is fully depressed. Insulin syringes with a fixed needle are low-dead-space designs; the EasyTouch listing describes its needle as a "Dead Space" design that "minimizes waste and allows for more accurate measuring". A detachable-needle syringe of the same barrel size leaves more liquid behind.

Sterility. A property of the sealed package. BD's filing describes the device as sterile and single use; once opened and used, neither word applies.

What the law says about buying them

Syringe sale is regulated by the states, and the rules differ. The one statute we could open on 2026-09-05 is California's. Business and Professions Code 4145.5 provides that "a physician or pharmacist" may furnish hypodermic needles and syringes without a prescription to "a person 18 years of age or older" for personal use, describes the provision as "a public health measure intended to prevent the transmission of HIV, viral hepatitis, and other bloodborne diseases", contains no quantity limit, and requires pharmacies to store needles securely, counsel on safe disposal, and provide information on drug treatment, testing and sharps disposal.

Other states' rules, as reported in secondary summaries we read but could not verify against the statute on the day: New York permits registered pharmacies to sell a limited number of syringes to adults without a prescription under its Expanded Syringe Access Program; North Carolina permits non-prescription sale with no age or quantity limit under a pharmacist's discretion; some states require proof of a medical need or a prescription. We do not restate figures we could not confirm. The state pharmacy board is the authority, and its website is the place to check before assuming a sale is lawful in a given state. Federal law does not require a prescription for syringes; it leaves the question to the states.

What CDC says about use

CDC's injection-safety guidance for clinical settings, page dated 2024-03-26, sets out the rules that the single-use label rests on: "One Needle, One Syringe, Only One Time"; "Do not administer medications from the same syringe to more than one patient, even if the needle is changed"; and "Once a multi-dose vial is opened (e.g., needle-punctured) the vial should be dated and discarded within 28 days" unless the manufacturer states another date (CDC). Those are rules for clinics. A laboratory sets its own sterile-technique rules, and this page does not write them.

What they cost

Prices observed on 2026-09-05, US dollars, before shipping and tax:

Product Specification Count Price Per syringe Where Prescription note on the page
EasyTouch Insulin Syringes 31 G x 5/16 inch, 1 mL (100 units), U-100 100 $23.99 $0.24 Diabetic Warehouse None stated; "check with your doctor" before changing size

BD Ultra-Fine and other brand-name listings at national pharmacies and marketplaces blocked our requests on the day, so no brand-name price is quoted; secondary listings we saw put BD at roughly two to three times the EasyTouch per-unit price, which we report as unverified. Research-peptide vendors' bundled syringe packs are not in the table: their prices are for small counts and, per FDA's letters, the bundling itself is what the agency reads as intended-use evidence.

What this page does not do

It does not describe how to draw up, measure or inject anything. It does not say which syringe to use. It does not rank the products. It reports the specifications, the regulation, the law we could open, the CDC rules and a dated price, and links each to its source.

Sources and dates

Opened 2026-09-05: 21 CFR 880.5860 (Cornell LII); FDA 510(k) summary K190054 (BD Insulin Syringe); California BPC 4145.5 (leginfo.legislature.ca.gov); CDC injection-safety guidance (2024-03-26); Diabetic Warehouse product page; FDA's warning letter to USApeptide.com (2025-02-26). Pages that blocked our requests and are therefore not quoted: embecta/BD product pages, ADW Diabetes, Walgreens, Shaw's, the New York Department of Health ESAP pages and NY Public Health Law 3381, and the North Carolina Board of Pharmacy FAQ. Corrections go to the contact page; who we are is on the about page.

Frequently asked questions

What size syringe is used for peptides?

This page does not give usage instructions. What it can tell you is what the sizes are: insulin syringes come in 0.3 mL, 0.5 mL and 1 mL barrels, graduated in units where 100 units is 1 mL, with needles from 27 G to 31 G and 6 mm to 16 mm long, per BD's FDA filing. Which barrel and needle suit a laboratory's protocol is a question for that protocol; the numbers on the box mean the same thing whatever the protocol is.

How many units are in 1 mL on an insulin syringe?

One hundred, on a U-100 syringe. The unit scale was designed for U-100 insulin, which contains 100 units per millilitre, so the marks are a volume scale: 10 units is 0.1 mL, 50 units is 0.5 mL, 100 units is 1 mL. A 0.3 mL syringe is marked to 30 units, often in half-unit steps; a 0.5 mL syringe to 50 units; a 1 mL syringe to 100 units in two-unit steps. U-40 and U-500 syringes exist for other insulin strengths and their marks do not mean 100 units per millilitre, which is why the label matters.

Do you need a prescription to buy insulin syringes?

It depends on the state. California's statute lets a pharmacist or physician furnish needles and syringes without a prescription to anyone 18 or older for personal use. Other states allow pharmacy sale with age limits, quantity caps per sale, pharmacist discretion, or a requirement to show a medical need, and a few require a prescription. We were able to open California's statute; state pharmacy-board pages for New York and North Carolina blocked our requests on 2026-09-05, so we do not restate their limits. The pharmacy board of the state in question is the source to check.

What does 31G 5/16 mean?

31 G is the needle gauge: the outside diameter of the cannula, on a scale where a higher number is thinner, so 31 G is thinner than 29 G and 27 G. 5/16 is the needle length in inches, which is 8 mm. BD's range also includes 6 mm (about 15/64 inch), 12.7 mm (1/2 inch) and 16 mm (5/8 inch) lengths.

Can an insulin syringe be reused?

CDC's guidance for clinical settings is one needle, one syringe, only one time, and never using the same syringe for more than one person even with a new needle. BD's FDA filing describes its insulin syringes as sterile, single use and non-pyrogenic; sterility is a property of an unopened package, not of a syringe that has been used and stored. Laboratories set their own sterile-technique rules; the device is designed and labeled for a single use.

How much do insulin syringes cost?

On 2026-09-05 a box of 100 EasyTouch 31 G x 5/16 inch 1 mL syringes was listed at $23.99 at Diabetic Warehouse, or $0.24 each. Brand-name BD syringes typically cost more per unit; the retail pages we tried for BD pricing blocked our requests that day, so we do not quote a figure. Pharmacy prices vary by state and by whether the sale is made without a prescription.