Basal Insulin

These instructions are for Children's Hospital of Philadelphia (CHOP) patients with diabetes who use basal insulin, also known as long-acting insulin.

Important information about basal insulin:

• Long-acting insulin, also called basal insulin, provides background insulin all day. This keeps blood sugars stable between meals and when you are asleep. Your body needs insulin all the time. Learn more about type 1 diabetes.

• Basal insulin does not peak like bolus insulin, which works quickly. Basal insulin works in the body for 18-36 hours (about 1 and a half days).

• Basal insulin is most often given once a day, usually in the evening. Sometimes it is ordered twice a day, at breakfast and dinner or bedtime.

• There are several brands and strengths of basal insulins. Your diabetes team will decide which medicine is best for you.

• The medicine is given as an injection into the layer of fat underneath the skin. This gives a slow, steady amount of insulin into the body to keep blood sugars in range.

• Basal insulin injections can be pre-filled insulin pens or pulled up in a syringe. Your team will teach you about the type and strength as well as how to give the medicine.

Patient instructions for basal insulin:

• Give the medicine when your diabetes provider has ordered it. Try to give basal insulin within the same hour every day.

• If you use more than one type of insulin, do not mix it with your basal insulin. You may give your basal insulin and your fast-acting insulin at the same time; just use a different injection site and different syringes if using vials.

• In rare cases, basal insulin can cause low blood sugar. Check your blood sugar immediately if you feel shaky, dizzy, irritable, and sweaty or have any other symptoms.

  • If your blood sugar is less than 70, take 4 glucose tablets or drink 4 ounces of juice. This equals 15 grams of carbohydrate. Avoid using chocolate or nuts to treat a low blood sugar as they will not work fast enough to correct the low.

Patient instructions for injections:

Subcutaneous injection sites

• Give basal insulin in a different site than any other insulin.

• Give the injection straight into the fat layer under your skin.

• Inject into:

  • Lower half of upper arm

  • Side of thigh

  • Buttocks

  • 2 inches away from your belly button on your stomach

• Use a different body area each week. Rotate the injections sites within the area you choose for each dose. Keep injections one inch apart. This helps the insulin absorb properly.

  • If the same area is used too much, a hard lump can form under the skin. This lump, called lipohypertrophy, takes 6-12 months to heal. During this time, the site cannot be used because insulin will not be absorbed well.

Instructions for leaking:

• If the medicine leaks from the injection site, you did not get your full insulin dose. As a result, your blood sugars may go up.

  • Do not repeat the dose.

  • Check blood sugar every 2 - 4 hours.

  • Check for ketones if the blood sugar is greater than 240.

  • Call the Diabetes Center if you have ketones.

  • Begin drinking more sugar-free fluids if you have ketones.

• To prevent leaking:

  • Slowly count to 5 after you inject all the insulin before pulling the needle out.

  • Inject straight down, not at an angle.

  • Use a longer needle if this happens often.

• Before it is opened, keep new insulin in the refrigerator door. Unopened insulin is good until the expiration date on the box if kept in the refrigerator.

• Once opened, store insulin according to the manufacturer's guidelines. Some types can be stored on the refrigerator door or at room temperature (50°F-80°F), while others need to be at room temperature. Keep insulin away from areas that are too hot or too cold.

  • Never store it in the glove compartment in your car.

  • Never freeze insulin.

• Throw out opened insulin as directed by the manufacturer and after 30 days of use. Date the vial or pen so you know when to open a new one. Please note insulin glargine should be discarded 28 days after opening.

• Dispose of syringes, needles, and lancets safely in a hard plastic container like a laundry detergent bottle. People are at risk of needle sticks if they are not discarded properly.

• Learn more about how to safely get rid of sharps at www.SafeNeedleDisposal.org. Your city, county or township will also have information. Some will provide a special disposal device at no cost.

Reviewed on March 1, 2023, by Lisa Miller, CDE, RD, LDN, CPT