Insulin therapy helps control blood sugar levels in diabetes. What type of insulin you take, how often you take it, and how it’s administered are all part of your individualized treatment plan.

For many people diagnosed with diabetes, insulin therapy may be necessary to keep blood sugar within a consistent, safe range. While insulin pumps and inhalers are options for some people, self-injections are a standard route of insulin administration for many people living with type 2 diabetes.

Insulin types vary based on their speed of effect, when they reach peak effectiveness, and how long they work. Your doctor will decide which type is right for you based on your diagnosis.

Different types of insulin and their common brand names include:

  • Rapid-acting: Starts working in 15 minutes with a peak onset of 1 hour. It’s usually taken immediately before a meal and lasts 2–4 hours. (Fiasp, NovoLog, Apidra, Humalog)
  • Regular/short acting: Starts working within 30 minutes with peak onset after 2–3 hours. Usually taken 30–60 minutes before a meal and lasts for 3–6 hours. (Humulin R, Novolin R, Velosulin R)
  • Intermediate acting: Starts working in 2–4 hours with peak onset between 4 and 12 hours. Lasts between 12 and 18 hours. (Humulin N, Novolin N, ReliOn)
  • Long-acting: Starts working 2 hours after administration and provides consistent dosing with no peak for up to 24 hours. (Tresiba, Levemir, Lantus)
  • Ultra-long acting: Starts working after 6 hours and provides consistent dosing with no peak for 36 hours or longer. (Toujeo)
  • Premixed: A combination of short-acting and intermediate-acting insulin that begins working within 5–60 minutes with varying peaks. Lasts between 10 and 16 hours and is typically taken 10–30 minutes before breakfast and dinner. (Humalog Mix, Novolog Mix, Ryzodeg)

Your prescribed insulin will also have a strength represented by a “U” number, which indicates how many units of insulin are in a milliliter of solution. The most common strength of insulin is U-100, but your doctor may prescribe other strengths, such as U-200, U-300, or U-500.

Insulin injections involve a needle and syringe or an insulin pen.

Needles and syringes are used to draw insulin from a vial each time you need an injection.

Insulin pens are handheld devices that contain pre-filled insulin cartridges or reservoirs. Like syringes, they have a needle for administration, but a dial on the pen sets your insulin dose. Insulin pens are available in reusable or disposable options.

No matter which option you choose, taking insulin means an injection. Insulin injections are administered just under the skin (subcutaneously), allowing the insulin to enter your bloodstream gradually.

You may feel a sensation similar to a pinprick, followed by burning, coldness, or tingling as the insulin is administered. For many people, insulin injections are mild and don’t cause any significant soreness or pain.

How often you take insulin will depend on factors such as the severity and type of diabetes, your insulin sensitivity, present complications, lifestyle, and current therapy goals.

Your insulin supplies will depend on your choice of injection method: syringe or insulin pen.

If you’re using a syringe to administer your insulin, you’ll need:

  • a syringe (typically comes with needles attached)
  • needles (if not attached to the syringe)
  • your vial of insulin
  • medical disposal container (sharps container)

If you’re using an insulin pen, you’ll need:

  • your insulin pen
  • an insulin cartridge if your pen is not disposable
  • disposable pen needle
  • medical disposal container (sharps container)
  • manufacturer instructions for your specific pen

The choice to use a syringe or a pen is often a matter of personal preference, though cost, insulin dose, and insurance coverage can affect your decision.

Benefits of insulin pens:

  • offer more precise dosing options
  • have smaller, thinner, more comfortable needles
  • are easier to use
  • are less conspicuous

Not all types of insulin can be used with a pen, however, and pens can be more expensive and are not covered by all insurance providers. Some pens may also have batteries that need to be monitored and replaced as needed.

Benefits of syringes:

  • are less expensive
  • can be used with all types of insulin
  • allow full hands-on control of the dosing and administration process
  • do not require any batteries
  • don’t have temperature requirements for storage or transport (though the insulin vial does)
  • may cause more injection site discomfort

The package insert will let you know how your insulin should be stored.

Most manufacturers recommend insulin be kept in the refrigerator, but your doctor may suggest keeping the bottle you’re using at room temperature if you find injecting cold insulin unpleasant.

Insulin can last up to 1 month at room temperature.

Avoid extreme temperatures when storing insulin, and never keep bottles in the freezer, in direct sunlight, or out in your car.

Used syringe needles, disposable pen needles, and disposable pens need to go in a medical waste container. These puncture-resistant containers, often called “sharps” containers, prevent accidental needlestick exposures that may pose a health risk.

Check with your health department about the disposal of needleless syringes, empty insulin vials, and pen casings. They can often go in your regular trash, though local restrictions may vary.

Your health department can also instruct you on what to do if you don’t have a sharps container handy. You may be able to place used needles in a heavy-duty plastic container with a secure lid, like an empty laundry detergent bottle.

When your container is full, it may need to be taken to an approved drop-off location like a healthcare facility, local pharmacy, or waste management facility. Your local health department can provide instructions.

Incorporating insulin into your daily life can take some getting used to. Keep a list of questions that you can add to as they arise, and bring the list to your next doctor appointment.