Insulin Aspart

Insulin Aspart Overview

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Insulin aspart is a prescription medication used to treat type 1 and type 2 diabetes. Insulin aspart is a fast-acting form of insulin. It is usually given with a long-acting insulin to provide a steady amount of insulin to control blood glucose (sugar) levels.

This medication comes in an injectable form available in vials and prefilled pens. Insulin aspart should be injected just under the skin 5 to 10 minutes before meals. It may also be injected directly into a vein (IV) by a healthcare provider or by an insulin pump.

Common side effects of insulin aspart include low blood sugar, reaction at the injection site, and weight gain.

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Uses of Insulin Aspart

Insulin aspart is a prescription medication used to control high blood sugar in adults and children with type 1 or type 2 diabetes.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Insulin Aspart Brand Names

Insulin Aspart may be found in some form under the following brand names:

Insulin Aspart Drug Class

Insulin Aspart is part of the drug class:

Side Effects of Insulin Aspart

Serious side effects may occur. See "Insulin Aspart Precautions" section.

Common side effects of insulin aspart include weight gain, reaction at the injection site, and low blood sugar.

Low blood sugar (hypoglycemia) is the most common side effect seen with insulin aspart use. Symptoms of low blood sugar may include:

  • sweating
  • dizziness or lightheadedness
  • shakiness
  • hunger
  • fast heart beat
  • tingling of lips and tongue
  • trouble concentrating or confusion
  • blurred vision
  • slurred speech
  • anxiety, irritability or mood changes
  • headache

Severe low blood sugar can cause unconsciousness (passing out), seizures, and death. Know your symptoms of low blood sugar. Follow your healthcare provider’s instructions for treating low blood sugar. Talk to your healthcare provider if low blood sugar is a problem for you.

Insulin Aspart Interactions

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

  • oral antidiabetic products, pramlintide, ACE inhibitors, disopyramide, fibrates, fluoxetine, monoamine oxidase inhibitors, propoxyphene, salicylates, somatostatin analogs, sulfonamide antibiotics. These medicines may increase the blood-glucose-lowering effect and susceptibility to hypoglycemia (low blood sugar).
  • corticosteroids, niacin, danazol, diuretics, sympathomimetic agents (e.g., epinephrine, salbutamol, terbutaline), isoniazid, phenothiazine derivatives, somatropin, thyroid hormones, estrogens, progestogens (e.g., in oral contraceptives), atypical antipsychotics. These medicines may reduce the blood-glucose-lowering effect.
  • Beta-blockers, clonidine, lithium salts, and alcohol. These may either potentiate or weaken the blood-glucose-lowering effect of insulin.
  • Pentamidine as it may cause hypoglycemia (low blood sugar), which may sometimes be followed by hyperglycemia (high blood sugar).
  • beta-blockers, clonidine, guanethidine, and reserpine. These medicines may reduce the signs of hypoglycemia (low blood sugar).

Insulin Aspart Precautions

Serious side effects can occur including:

  • Serious allergic reaction (whole body reaction). Get medical help right away, if you develop a rash over your whole body, have trouble breathing, a fast heartbeat, or sweating.
  • Reactions at the injection site (local allergic reaction). You may get redness, swelling, and itching at the injection site. If you keep having skin reactions or they are serious talk to your healthcare provider. You may need to stop using insulin aspart and use a different insulin. Do not inject insulin into skin that is red, swollen, or itchy.
  • Skin thickens or pits at the injection site (lipodystrophy). Change (rotate) where you inject your insulin to help to prevent these skin changes from happening. Do not inject insulin into this type of skin.
  • Swelling of your hands and feet
  • Vision changes
  • Low potassium in your blood (hypokalemia)
  • Weight gain

Do not take insulin aspart if:

  • Your blood sugar is too low (hypoglycemia).
  • You are allergic to anything in insulin aspart. Check with your doctor if you are not sure.

While using insulin aspart avoid:

  • Alcohol. Alcohol, including beer and wine, may affect your blood sugar when you take insulin aspart.
  • Driving and operating machinery. You may have difficulty concentrating or reacting if you have low blood sugar (hypoglycemia). Be careful when you drive a car or operate machinery.  

Ask your doctor if it is alright to drive if you often have:

  • low blood sugar
  • decreased or no warning signs of low blood sugar

Insulin Aspart Food Interactions

Follow dietary (food) recommendations made by your doctor and dietitian which should include a healthy diet. Skipping meals should be avoided as this can cause problems maintaining blood sugar control. There are no specific foods to avoid while using insulin aspart.

Inform MD

Before using insulin aspart, tell your doctor:

  • if you are allergic to anything in insulin aspart.
  • about all of your medical conditions. Medical conditions can affect your insulin needs and your dose of insulin aspart.
  • if you are pregnant or breastfeeding. You and your healthcare provider should talk about the best way to manage your diabetes while you are pregnant or breastfeeding. Insulin aspart has not been studied in nursing women.
  • about all medicines you take, including prescriptions and non-prescription medicines, vitamins and herbal supplements. Your insulin aspart dose may change if you take other medicines.

Insulin Aspart and Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Insulin aspart falls into category B. In animal studies, pregnant animals were given insulin aspart, and some babies had problems. 

It is very important to maintain control of your blood sugar levels during pregnancy. Your doctor will decide which insulin is best for you during your pregnancy.

Insulin Aspart and Lactation

Tell your doctor if you are breastfeeding. You and your doctor should talk about the best way to manage your diabetes while you are breastfeeding. Insulin aspart has not been studied in nursing women.

Insulin Aspart Usage

Only use insulin aspart if it appears clear and colorless. There may be air bubbles. This is normal. If it looks cloudy, thickened, or colored, or if it contains solid particles do not use it.

Read the instructions for use that come with your insulin aspart product. Talk to your doctor if you have any questions. Your doctor should show you how to inject insulin aspart before you start taking it.

  • Take insulin aspart exactly as prescribed. You should eat a meal within 5 to 10 minutes after using insulin aspart to avoid low blood sugar.
  • Insulin aspart is a fast-acting insulin. The effects of insulin aspart start working 10 to 20 minutes after injection or bolus pump infusion.
  • Do not inject insulin aspart if you do not plan to eat right after your injection or bolus pump infusion.
  • The greatest blood sugar lowering effect is between 1 and 3 hours after the injection or infusion. This blood sugar lowering lasts for 3 to 5 hours.
  • While using insulin aspart you may have to change your total dose of insulin, your dose of longer-acting insulin, or the number of injections of longer-acting insulin you use. Pump users given insulin aspart may need to change the amount of total insulin given as a basal infusion.


Do not mix insulin aspart:

  • with any other insulins when used in a pump
  • with any insulins other than NPH when used with injections by syringe

If your doctor recommends diluting insulin aspart, follow your doctor's instructions exactly so that you know:

  • How to make insulin aspart more dilute (that is, a smaller number of units of insulin aspart for a given amount of liquid) and
  • How to use this more dilute form of insulin aspart. Do not use dilute insulin in a pump.
  • Inject insulin aspart into the skin of your stomach area, upper arms, buttocks or upper legs. Insulin aspart may affect your blood sugar levels sooner if you inject it into the skin of your stomach area. Never inject insulin aspart into a vein or into a muscle.
  • Change (rotate) your injection site within the chosen area (for example, stomach or upper arm) with each dose. Do not inject into the exact same spot for each injection.

If you take too much insulin aspart, your blood sugar may fall low (hypoglycemia). You can treat mild low blood sugar (hypoglycemia) by drinking or eating something sugary right away (fruit juice, sugar candies, or glucose tablets). It is important to treat low blood sugar (hypoglycemia) right away because it could get worse and you could pass out (become unconscious). If you pass out you will need help from another person or emergency medical services right away, and will need treatment with a glucagon injection or treatment at a hospital.


If you forget to take your dose of insulin aspart, your blood sugar may go too high (hyperglycemia). If high blood sugar (hyperglycemia) is not treated it can lead to serious problems, like loss of consciousness (passing out), coma or even death. Follow your doctor’s instructions for treating high blood sugar.

Insulin Aspart Dosage

  • Take insulin aspart exactly as prescribed by your doctor.
  • Follow the directions on your prescription label carefully.
  • Your doctor will determine the best dose for you. The dosage of insulin aspart must be individualized.

Insulin Aspart Overdose

If you take too much insulin aspart, your blood sugar may fall low (hypoglycemia). You can treat mild low blood sugar (hypoglycemia) by drinking or eating something sugary right away (fruit juice, sugar candies, or glucose tablets).

It is important to treat low blood sugar (hypoglycemia) right away because it could get worse and you could pass out (become unconscious).

If you pass out you will need help from another person or emergency medical services right away, and will need treatment with a glucagon injection or treatment at a hospital.


Other Requirements

All Unopened insulin aspart:

  • Keep all unopened insulin aspart in the refrigerator between 36° to 46°F (2° to 8°C).
  • Do not freeze. Do not use insulin aspart if it has been frozen.
  • Keep unopened insulin aspart in the carton to protect from light.

Insulin aspart in use:

Vials

  • Keep in the refrigerator or at room temperature below 86°F (30°C) for up to 28 days.
  • Keep vials away from direct heat or light.
  • Throw away an opened vial after 28 days of use, even if there is insulin left in the vial.
  • Do not draw up insulin aspart into a syringe and store for later use.
  • Unopened vials can be used until the expiration date on the insulin aspart label, if the medicine has been stored in a refrigerator.

PenFill Cartridges or insulin aspart FlexPen

  • Keep at room temperature below 86°F (30°C) for up to 28 days.
  • Do not store a PenFill cartridge or insulin aspart FlexPen that you are using in the refrigerator.
  • Keep PenFill cartridges and insulin aspart FlexPen away from direct heat or light.
  • Throw away a used PenFill cartridge or insulin aspart FlexPen after 28 days, even if there is insulin left in the cartridge or syringe.
  • Insulin aspart in the pump reservoir and the complete external pump infusion set.
  • The infusion set and the infusion site should be changed at least every 3 days. The insulin in the reservoir should be changed at least every 6 days even if you have not used all of the insulin. Change the infusion set and the infusion site more often than every 3 days if you have high blood sugar (hyperglycemia), the pump alarm sounds, or the insulin flow is blocked (occlusion).