NovoLog (insulin aspart) is a fast-acting insulin used for diabetes treatment. It’s injected 5 to 10 minutes before meals. It may be prescribed with other insulins or oral diabetes drugs.
NovoLog is used to manage blood sugar levels in adults and children with type 1 or type 2 diabetes.
NovoLog starts working within about 5 to 10 minutes after you inject it. Its peak effect on blood sugar levels occurs 1 to 3 hours after injection, and its effects last for 3 to 5 hours. Keep in mind that this timing can vary from person to person.
NovoLog is a biologic drug, meaning it’s made from parts of living organisms. A biosimilar form called Merilog (insulin aspart-szjj) is also available. A biosimilar is like a generic version of a biologic drug.
You should inject NovoLog 5 to 10 minutes before each meal. It’s given as an injection under the skin using:
- a prefilled NovoLog FlexPen
- prefilled NovoLog PenFill cartridges (used with a compatible insulin pen, such as the NovoPen Echo)
- syringes or an insulin pump (used with a vial of NovoLog solution)
The FlexPen and PenFill cartridges contain 3 milliliters (mL) of NovoLog solution, and the vial contains 10 mL. For instructions on how to use the FlexPen and the NovoPen Echo, see the NovoLog website. You can also view the drug’s prescribing information.
Here are some questions related to using NovoLog:
- Where can I inject NovoLog? You can inject NovoLog into your abdomen, the front of your thigh, your upper arm, or your buttocks.
- Should I still take Novolog if I skip a meal? No. If you skip a meal, you should also skip that NovoLog dose. If you inject a dose and do not start eating within 5 to 10 minutes, your blood sugar may get too low.
- What if I miss a dose? If you’ve already started eating a meal, you can take NovoLog mid-meal. If you remember after you’ve eaten a meal, check your blood sugar to determine if you need a dose to lower your blood sugar. If you aren’t sure what to do, contact your doctor or a pharmacist for advice.
In some cases, doctors may administer NovoLog as an intravenous (IV) infusion in a hospital setting.
NovoLog’s mechanism of action (how it works) is to mimic the job of natural insulin. With diabetes, your body doesn’t make insulin or can’t use it properly. Like natural insulin, NovoLog tells your body to move sugar out of your blood and into your body’s cells. This lowers your blood sugar level.
Find answers to some commonly asked questions about NovoLog.
How does NovoLog compare with other forms of insulin for diabetes?
The following table summarizes how NovoLog compares with some other insulins used to treat diabetes.
| Drug name | Active ingredient | Type of insulin |
|---|---|---|
| NovoLog | insulin aspart | fast-acting insulin (also called mealtime insulin) |
| Humalog Admelog | insulin lispro | fast-acting insulin |
| Fiasp | insulin aspart and niacinamide (vitamin B3, which is meant to help Fiasp start working faster than NovoLog) | fast-acting insulin |
| Novolin | NPH insulin (insulin isophane human) | • Novolin R: regular insulin (also called short-acting insulin) • Novolin N: intermediate-acting insulin • Novolin 70/30: mixture of intermediate-acting and regular insulins |
| Basaglar | insulin glargine | long-acting insulin (also called basal insulin) |
This is not a comprehensive list of all available insulins. Be sure to talk with your doctor if you’re considering other treatment options.
Does NovoLog need to be refrigerated? When does the drug expire after it’s been opened?
Before you open NovoLog, you can refrigerate it or keep it at room temperature. How you store it affects how soon it expires:
- Unopened at room temperature, NovoLog is good for up to 28 days
- Unopened in the refrigerator (36°F to 46°F or 2°C to 8°C), NovoLog is good until the expiration date on the box.
After you open a NovoLog pen, keep it at room temperature (up to 86°F or 30°C). Don’t put it back in the refrigerator. After you open a NovoLog vial, you can store it at room temperature or in the refrigerator.
Be sure to use NovoLog within 28 days of opening it.
NovoLog’s more common side effects include headache, weak muscle reflexes, nausea, and fungal infection of the nails. Other possible side effects can be mild or serious, and can include:
- diarrhea
- low blood sugar
- injection site reactions, such as pain, swelling, or skin redness or discoloration
- allergic reaction
These are not all of the side effects reported with NovoLog. You can talk with your doctor or pharmacist, or refer to the drug’s prescribing information for details. You can also refer to this NovoLog side effects overview.
Allergic reactionFor some people, NovoLog can cause an allergic reaction. In general, symptoms of an allergic reaction can be mild or serious.
If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away.
Your doctor will recommend the specific NovoLog dose that’s best for you based on your blood sugar levels, diet, physical activity level, and other factors.
If you’re using NovoLog with an insulin pump, talk with your doctor about your dosage instructions.
If you think you’ve taken too much NovoLog, call your doctor or call America’s Poison Centers at 800-222-1222 or through its online resource. If you have severe symptoms, immediately call 911 or your local emergency number. Or go to the nearest emergency room.
What you’ll pay for NovoLog may depend on several factors, such as your treatment plan and the pharmacy you use. Here are a few things to consider:
- Savings options and coupons: Some NovoLog savings options are available from the drug manufacturer, including help understanding your insurance coverage. You can also visit Optum Perks for price estimates of NovoLog based on the use of Optum Perks coupons. (These coupons cannot be used with insurance copays or benefits.)
- NovoLog supplies: You’ll need some supplies to inject NovoLog (such as insulin syringes, pen needles, an insulin pump, or a reusable insulin pen device), and their cost can vary.
It’s best to avoid or limit alcohol use during your Novolog treatment. Alcohol can affect your blood sugar levels, which could make NovoLog less effective. It can also raise your risk of certain NovoLog side effects.
If you drink alcohol, talk with your doctor about the amount (if any) that may be safe to consume during Novolog treatment.
Talk with your doctor about your health history before you take NovoLog, particularly about any history of:
- heart failure
- kidney or liver problems
- allergic reaction to NovoLog or any of its ingredients
You should not use NovoLog during an episode of hypoglycemia (low blood sugar). Know the risk factors for hypoglycemia, such as changes in your meal routine, physical activity level, or your dosage of insulin or other diabetes drugs.
It’s not known whether it’s safe to take NovoLog while pregnant or breastfeeding. If you’re pregnant, breastfeeding, or planning on either, talk with your doctor about your options.
NovoLog can interact with several types of drugs, including:
- some other diabetes drugs, such as:
- certain blood pressure drugs, including:
- beta-blockers such as metoprolol (Lopressor, Toprol-XL)
- angiotensin converting enzyme (ACE) inhibitors such as lisinopril (Zestril)
- angiotensin receptor blockers (ARBs) such as losartan (Cozaar)
- corticosteroids such as prednisone (Prednisone Intensol)
- diuretics such as furosemide (Lasix)
- certain mental health medications, including:
- clozapine (Clozaril)
- fluoxetine (Prozac)
- lithium (Lithobid)
- birth control pills such as ethinyl estradiol/drospirenone (Nikki, Loryna, others)
- certain HIV medications such as lopinavir/ritonavir (Kaletra)
- thyroid hormone replacements, such as levothyroxine (Synthroid)
This list does not contain all drugs that may interact with NovoLog. Be sure to tell your doctor about all medications you take, including prescription and over-the-counter types, and any vitamins, herbs, or supplements you take.
Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
