Insulin Clinics / Foundations

How insulin is delivered

Insulin can be given by syringe, pen, pump, or inhaler. Each has trade-offs in cost, convenience, precision, and the kind of life it fits into.

Last updated: October 2026 · Based on ADA Standards of Care, FDA prescribing information, and NIDDK · General information, not medical advice — see our editorial policy

Vials and syringes

The original delivery method, and still the cheapest. Insulin comes in a glass vial (usually 10 mL of U-100) and is drawn into a single-use syringe before each injection. Syringes come in different sizes — 0.3 mL (up to 30 units), 0.5 mL (up to 50 units), and 1 mL (up to 100 units) — with the needle permanently attached, usually 6 mm, 8 mm, or 12.7 mm long. See the insulin syringe guide for how to read sizes and markings.

Pros

• Lowest cost per dose by a wide margin, especially with older insulins.
• Easy to mix two insulins in one syringe (for example, NPH and regular).
• Widely available; in many U.S. states syringes can be bought at a pharmacy without a prescription (rules vary by state and country).

Cons

• More steps before each dose, more room for error.
• Drawing tiny doses (less than 5 units) is harder to do accurately.
• Less discreet in public.

Disposable insulin pens

A disposable pen is a single device pre-filled with insulin (usually 300 units; concentrated-insulin pens hold more, from 450 to 1,500 units). You attach a fresh pen needle, dial the dose, inject, and remove the needle. When the pen is empty, the whole device is thrown away. Most modern insulins come in this form.

Pros

• Faster than vials and syringes; fewer steps.
• Dose dial is easier to read and more accurate, especially for small doses or vision problems.
• More portable and discreet.

Cons

• Higher cost than vials, especially in the U.S.
• You cannot mix two insulins in one device.
• Pen needles are an additional supply that may be billed separately.

Reusable pens with cartridges

Reusable pens are durable devices (metal or plastic) that take a replaceable cartridge of insulin. They are common outside the U.S. and used by some U.S. patients. The pen lasts for years; only the 3 mL cartridges and pen needles get replaced. Some reusable "smart" or memory pens record the time and amount of each dose, and add-on caps or buttons can do the same for some disposable pens. Reusable pens generate less plastic waste and can be slightly cheaper over time, depending on the cartridge price.

Insulin pumps

An insulin pump is a small device that delivers rapid-acting insulin continuously through a thin tube and a cannula (a soft plastic tube under the skin), or directly through a patch. The user — or in newer systems, the algorithm — also instructs the pump to deliver bolus doses for meals and corrections.

Tubed pumps

A tubed pump (for example Tandem t:slim X2 and Mobi, the MiniMed 780G, and the twiist system) is worn clipped to a belt or in a pocket. The MiniMed 780G is now made by MiniMed, formerly Medtronic Diabetes. Thin tubing connects it to an infusion set placed on the abdomen, thigh, or another fatty area. The infusion set is usually changed every 2–3 days (some extended-wear sets last up to 7 days); the pump itself lasts 4 years or more.

Patch pumps

A patch pump (for example Omnipod 5) sticks directly to the skin. There is no tubing; the pump and infusion site are one unit, controlled wirelessly from a phone or controller. Each "pod" lasts about 3 days, then is removed and a new one is placed.

Hybrid closed-loop systems

The most important shift in insulin delivery in the last decade is the hybrid closed-loop system, sometimes called an "artificial pancreas." A continuous glucose monitor (CGM) talks to the pump, and an algorithm adjusts basal insulin every few minutes based on glucose trends. The user still announces meals and confirms boluses — that is the "hybrid" part — but overnight basal regulation is largely automatic.

Studies and real-world data show these systems consistently increase time in the target glucose range and reduce overnight lows compared with manual pumps or injections in type 1 diabetes. They are also approved for type 2 diabetes in some cases. Examples include Tandem systems with Control-IQ technology, the MiniMed 780G, Omnipod 5, and the twiist system. Available models change often, so ask your care team what is current and covered. The iLet Bionic Pancreas takes a simpler approach where the user announces a meal as "usual for me," "more," or "less" rather than counting carbs.

Pros and cons of pump therapy

Pumps offer fine-grained control (basal rates can vary by hour, doses can be 0.025 units in some pumps) and remove the need for multiple daily injections. Closed-loop pumps add automated correction overnight and during exercise, which is where most people get into trouble.

The trade-offs: pumps are expensive (the device, the supplies, the CGM), they require training to use safely, an infusion set failure can cause rapid hyperglycemia and DKA because there is no long-acting insulin in the body, and many people simply do not want a device attached to them.

Inhaled insulin

Inhaled insulin (Afrezza) is a fine powder of human insulin breathed in through a small inhaler at the start of a meal. It absorbs through the lungs, starts working within minutes, and its effect usually lasts about 1.5–3 hours at typical doses (longer with large doses). The inhaled insulin guide covers it in depth.

It is approved as a mealtime insulin only, for adults and children 6 years and older — it does not replace basal insulin. It comes in 4-, 8-, and 12-unit cartridges, which makes very fine dose adjustments harder. It is not appropriate for people with asthma, COPD, or other chronic lung disease, and the prescribing information calls for a lung function test (spirometry) before starting, after 6 months, and yearly after that. It is not recommended for people who smoke or recently quit. Some people who dislike injections find it valuable; others find the cost or the dose granularity limiting.

Cost considerations

Across all of these methods, cost varies dramatically by insurance, geography, and the specific product. As a rough ordering in the U.S.:

• Lowest: regular and NPH human insulin in vials with syringes (for example Walmart's ReliOn line, which has been priced at roughly $25 per vial — prices change, so check locally).
• Moderate: analog insulin in vials; some biosimilar pens.
• Higher: brand-name analog pens; pump supplies; CGM sensors.
• Highest: hybrid closed-loop systems including pump, supplies, and CGM together.

The cost and access page covers patient assistance programs, the $35-per-month Medicare insulin cap, and what to do when you cannot afford this month's supply.

Who tends to use what

There is no single right answer. Some patterns are common:

• People newly starting insulin in type 2 diabetes most often begin with a pen for once-daily basal insulin.
• Pediatric type 1 diabetes care has shifted heavily toward CGMs and pumps, especially closed-loop systems.
• Adults with type 1 diabetes split roughly between multiple daily injections (with a CGM) and pumps; both can produce excellent results.
• People with limited insurance, or who travel to places where supplies are uncertain, often choose injection-based regimens for resilience.
• People with very small total daily doses (some children, some adults with high insulin sensitivity) benefit from pumps that deliver in fractions of a unit.

The right delivery method is the one you will actually use reliably, that you can afford, and that your care team can support. It is reasonable — and common — to switch over time as needs and circumstances change.

Frequently asked questions