Humalog (Insulin Lispro Injection) Subcutaneous/Intravenous: Uses, Side Effects, Dosage

What Is Humalog?

Humalog (insulin lispro injection) is a prescription rapid-acting injectable insulin analog (eg., it’s a manufactured insulin). This medication is used to treat diabetes. It works by lowering blood glucose (sugar) in the body.

What Is Humalog Used For?

Humalog is a treatment option for type 1 and also type 2 diabetes (high blood sugar). In the United States, the Centers for Disease Control and Prevention (CDC) estimates that diabetes affects more than 37 million people—with prediabetes (when blood sugar is high but not high enough to be diagnosed as diabetes) affecting an additional 96 million people.

The National Diabetes Prevention Program (DPP) helps prevent or delay diabetes in people with prediabetes. If you have prediabetes and would like to know more about chapters of the DPP in your area, ask your healthcare provider for more information or contact a local program.

If you have diabetes, you might experience the following symptoms:

• Extreme hunger and thirst
• Frequent urination (peeing)
• Weight loss 

Over time, uncontrolled high blood sugar levels can lead to diabetes-related complications, including neuropathy (nerve pain or numbness), diabetic foot sores, amputations, eye problems, and kidney impairment.

Diabetes can also raise your risk of heart disease and stroke, which are the leading causes of death in the United States.

How to Take Humalog

In general, when using Humalog, take the following precautions:

• Carefully check the labeling on the package or container to make sure that you’re using the correct insulin product.
• Humalog should be clear and colorless. If you notice any color, cloudiness, or particles, don’t use it.
• Wash your hands with soap and water.
• If you’re using Humalog through a pen or an infusion pump, don’t dilute (water down) the insulin.
• Don’t dilute Humalog from vials on your own.
• When using an infusion pump, don’t mix Humalog U-100 with other insulins. 
• If you’re injecting Humalog U-100 under your skin without an infusion pump, however, Humalog U-100 can be mixed with Neutral Protamine Hagedorn (NPH) insulins—like Humalin N or Novolin N. Other than NPH insulins, however, don’t mix Humalog U-100 with any other insulins.
• If you’re going to mix Humalog U-100 with an NPH insulin, draw Humalog U-100 into the syringe first before drawing up the NPH insulin product. For more detailed directions about missing insulins, talk with your pharmacist or healthcare provider.
• If you’re injecting Humalog under the skin without an infusion pump, use Humalog within 15 minutes before or immediately after your meal.
• Don’t use Humalog U-200 in an infusion pump.
• Don’t mix Humalog U-200 with other insulins. 
• Don’t self-inject any type of Humalog directly into your vein. 
• When switching between the Humalog U-100 and U-200 pens, there is no need to convert your dose. The pen has a dose window that shows the dose (in units) that you will inject.
• Don’t transfer Humalog U-200 from a prefilled pen into a syringe. Just use the Humalog U-200 pen to directly inject the insulin under your skin.
• Don’t repeatedly use the exact same injection or insertion (infusion) site within the same body region. Repeatedly injecting or infusing insulin in the exact same spot will raise your risk of thick, pitted, and lumpy skin. 
• Don’t inject insulin into tender, bruised, scarred, pitted or damaged skin areas. Also, avoid skin that is scaly, hard, lumpy or thick.

Your healthcare provider can recommend which route you’ll use for your Humalog, which includes:

• Subcutaneous infusion through an insulin pump: If you’re going to use Humalog U-100 in an infusion pump, check the directions, which vary for each pump. Carefully read the labeling and packaging instructions. Talk with your pharmacist or healthcare provider for detailed information. In general, remember to change the Humalog in your pump reservoir every week, or after exposure to temperatures over 98.6 degrees Fahrenheit. Change your infusion sets and infusion set insertions at least every three days. Also, rotate your insertion (infusion) site within your chosen body region every three days. If you’re using a Humalog 3 milliliter (mL) cartridge for your D-Tron pump, you will need to throw away your cartridge every seven days.
• Intravenous (into your vein) infusion: If you’re receiving Humalog U-100 as an intravenous infusion, your healthcare provider will help give this infusion to you. Don’t self-inject Humalog directly into your vein.
• Subcutaneous (under your skin) injection: More on this next.

If you’re going to inject Humalog under your skin (subcutaneous), the specific directions will vary per person. Use Humalog according to your healthcare provider’s recommendations. The following, however, are some typical steps to inject Humalog under your skin.

Humalog Vial

1. Use an alcohol swab to clean your injection site, then allow your site to dry.
2. Use an alcohol swab to clean the rubber stopper of your Humalog vial.
3. Carefully remove the cap protecting the needle of your syringe.
4. Fill your syringe with air by pulling the plunger of your syringe back until the black tip reaches the marking of your Humalog dose in units.
5. Push the needle through the rubber stopper of your vial, and push the plunger all the way down to force air into your vial.
6. Turn your vial with the inserted syringe upside down.
7. Then, slowly pull the plunger back until the black tip reaches the marking of your Humalog dose in units.
8. If you notice any air bubbles, gently tap the syringe a few times to move the air bubbles to the top of your syringe—which is near the needle.
9. If necessary, adjust the plunger in or out until the black tip is at the appropriate marking (unit) for your Humalog dose. 
10. Without moving the plunger, pull your syringe to remove the needle from the rubber stopper of your insulin vial.
11. With one hand, gently pinch a fold of skin at your injection site which can be in one of the following body regions: butt cheeks, stomach, thigh or upper arms. The need to pinch a fold of skin will vary for each person. Talk with your healthcare provider to discuss the necessity of pinching your skin.
12. Using your other hand, hold your syringe with the needle at a 45-degree to a 90-degree angle to your injection site.
13. Continue to pinch your fold of skin while inserting the needle into your injection site and pushing the plunger of your syringe until there is no more insulin left in your syringe.
14. Keep the needle in your skin for a minimum of five seconds.
15. Gently stop pinching the fold of your skin and remove the needle. 
16. If you notice blood after you take out the needle from your skin, use a piece of gauze to gently press down on your injection site. Don’t rub the area.
17. Throw away your syringe with the attached needle in one of the following containers: red biohazard (sharps) container, hard plastic container (e.g., detergent bottle), or a metal container (e.g., empty coffee can). For additional information on how to appropriately and legally throw away your syringes and needles, talk with your pharmacist.

Humalog KwikPen

1. Use an alcohol swab to clean your injection site, then allow the site to dry.
2. Remove the cap from your Humalog KwikPen.
3. Use an alcohol swab to clean the rubber stopper of your KwikPen.
4. Peel off the circular paperlike seal from the needle.
5. Attach and screw the needle to your KwikPen.
6. Remove the big outer needle cap.
7. Remove the inner needle cap.
8. Turn the dose selector to two units.
9. Hold your KwikPen with the needle pointing up.
10. Use your finger to gently tap the cartridge window to move the air bubbles to the top of the cartridge—which is near the needle.
11. Continuing to hold your KwikPen with the needle pointing up, press the push-button on the other end of the KwikPen for five seconds. You should see the dose selector return to zero and a drop of insulin on the needle tip.
12. If you don’t see a drop of insulin on the needle tip, remove this needle, replace it with a new needle, and follow steps 1 through 11 again. Repeat step 12 until you see a drop of insulin on the needle tip. If you don’t see a drop of insulin on the needle tip by the fifth attempt for the U-100 pen or the ninth attempt for the U-200 pen, don’t use this pen and call the manufacturer (Eli Lilly) at 800-545-5979. You can also reach out to your pharmacist for assistance. 
13. With the dose selector back at number zero, turn the dose selector again until you reach the number of units that you’ve been instructed to inject for your situation. Make sure that the pointer lines up with your dose in units. 
14. With one hand, gently pinch a fold of skin at your injection site. The need to pinch the skin will vary per person. Talk with your healthcare provider to discuss the necessity of pinching your skin.
15. Using your other hand, hold your KwikPen with the needle at a 90 degree angle to the injection site. Be careful not to press the push-button yet.
16. Continue to pinch a fold of your skin while inserting the needle into the injection site and pressing the push-button all the way in until the dose selector returns to zero. The pointer should be lined up to the number zero. Keep the needle in your skin for a minimum of five seconds.
17. Gently stop pinching the fold of your skin and remove the needle. Make sure to hold the push-button until the needle is out of your skin. It is normal to see a drop of insulin on the needle tip.
18. If you see blood after you remove the needle from your skin, use a piece of gauze to gently press down on your injection site. Don’t rub the area.
19. Remove the needle from your KwikPen and throw it in one of the following containers: red biohazard (sharps) container, hard plastic container (e.g., detergent bottle), or a metal container (e.g., empty coffee can). For additional information on how to appropriately and legally throw away your syringes and needles, talk with your pharmacist.
20. Place the cap back on your Humalog KwikPen.

Storage

After bringing Humalog home from the pharmacy, you’ll need to protect your insulin from heat and light. Also, avoid freezing insulin. You can place unused vials and pens in your refrigerator between 36 degrees and 46 degrees. These refrigerated and unused vials and pens will last until the expiration date on the container or packaging.

If you prefer to store your unopened vials or unused pens at room temperature, however, then these products will only last for 28 days. Once you open a Humalog vial, you can store it in your fridge or at room temperature. But you will need to throw it away after 28 days. Once you use a Humalog pen, on the other hand, you can only store it at room temperature. And after 28 days, you will also need to throw it away.

If your healthcare provider recommends diluted (watered down) Humalog U-100 for you to inject under your skin, your healthcare provider will help you dilute your insulin in an appropriate amount and type of liquid. This diluted Humalog U-100 will be in good condition for 28 days in your refrigerator at 41 degrees. If you’re going to store your diluted Humalog U-100 at 86 degrees—which is above room temperature, your insulin will expire in 14 days.

If you are going to travel with Humalog, familiarize yourself with the regulations of your final destination. Make a copy of your Humalog prescription and consider asking your healthcare provider for documentation of medical necessity on a letter with an official letterhead. Also, have the original packaging or container with your name on it—from your pharmacy.

If you are carrying empty syringes, make sure to have Humalog physically on your person. You may also want to have an insulated bag with cold packs to prevent your insulin from getting too hot.

What Are the Side Effects of Humalog?

Similar to other insulins, side effects are possible with Humalog.

This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the Food and Drug Administration (FDA) at fda.gov/medwatch or 800-FDA-1088.

Common Side Effects

Common side effects with Humalog include:

• Itchiness
• Lipodystrophy (abnormal fat distribution)
• Low blood sugar
• Rash
• Reactions at your injection or insertion site (area where you inject or infuse your insulin)
• Swelling of your hands and feet
• Weight gain

Severe Side Effects

Seek immediate medical attention if you experience any of the following severe side effects:

• Extremely low blood sugar: If you’re experiencing severely low blood sugar, you may experience clumsiness, coma, confusion, seizures, and slurred speech. If your blood sugar is this low, use the glucagon product that your healthcare provider prescribed.
• Extremely high blood sugar: If your blood sugar gets too high, you can develop diabetic ketoacidosis, which is a life-threatening condition of high ketones due to fat breakdown in your body. Symptoms of ketoacidosis, include dry mouth, fruity-smelling breath, nausea, and vomiting.
• Heart failure: If you’re having heart failure, you might notice appetite loss, breathing problems, confusion, excessive sweating, and fast heart rate. You may also notice coughing and wheezing that don’t go away.
• Low potassium: If you have low amounts of potassium in your body, you may also have symptoms of abnormal heartbeat, constipation, muscle spasms, and numb or tingly sensations in your body.
• Severe allergic reaction: If you’re experiencing a severe allergic reaction, symptoms may include breathing problems, fast heartbeat, rash and sweating. You might also feel faint.

Long-Term Side Effects

Repeatedly using the exact same injection or insertion (infusion) spot raises your risk of lipodystrophy, which is an abnormal distribution of fat. This medical condition can lead to pitted-looking skin due to thinning of your fat tissue. It can also cause thick-looking skin due to the thickening of fat tissue.

Dosage: How Much Humalog Should I Take?

Modifications

Pregnant people: In reference to currently available data, there is no connection between using Humalog and negative effects on your unborn fetus. Uncontrolled diabetes, however, can raise your chance of miscarriage, preterm birth, stillbirth and delivery complications. Be sure to discuss any concerns with your healthcare provider.

Breastfeeding people: Data about the effect of Humalog on nursing babies are lacking. Discuss any questions that you may have about using Humalog while nursing with your healthcare provider.

Children: The FDA approved Humalog to treat type 1 diabetes in children. You can use Humalog as under-the-skin injections. You can also use Humalog U-100 in an infusion pump. The manufacturer of this medicine, however, hasn’t studied Humalog for use in children under 3 years old or in children with type 2 diabetes.

People with kidney or liver problems: People with kidney or liver problems have a higher risk of low blood sugar with Humalog. As a result, your healthcare provider may recommend closely monitoring your blood sugar and adjusting your insulin dose as needed.

Missed Dose

Humalog is typically used 15 minutes before or right after a meal. If you remember your missed Humalog dose before or right after mealtime, then immediately inject your missed dose. If some time (e.g., more than one hour) has passed since your missed dose, you can usually wait until your next scheduled meal and dosing time.

If you’re using Humalog in your insulin pump, perform the following maintenance tasks as soon as you remember:

• Change the Humalog in your pump reservoir every week or if it’s been exposed to temperatures over 98.6 degrees. 
• Change your infusion sets and infusion set insertions at least every three days.
• Rotate your insertion (infusion) site within your chosen body region every three days. 
• If you’re using a Humalog 3 milliliter cartridge for your D-Tron pump, you will need to throw away your cartridge every seven days.

Don’t try to double up and use extra insulin to make up for missed doses.

Since next steps to take after a missed Humalog dose will vary per person, refer to your healthcare provider’s recommendations. If you still have questions or concerns, call your healthcare provider.

Do your best to work toward finding ways to regularly remember your Humalog doses and insulin pump maintenance tasks. Forgetting doses and insulin pump maintenance tasks can cause uncontrolled high blood sugar levels and side effects. Over time, these high blood sugar levels can result in diabetes-related complications—like amputations, eye problems, heart disease, kidney problems and stroke.

Overdose: What Happens If I Take Too Much Humalog?

If you accidentally use too much Humalog, you may experience low blood sugar symptoms—like fast heartbeat, hunger, irritability, sweating, and tremors. So, if your blood sugar isn’t too low, use the following “15-15 rule”:

1. Eat or drink 15 grams of carbohydrates (carbs), which is a type of macronutrient in foods and drinks. The following are some examples of 15 grams of carbs: glucose tablets or gel tube—read the label to understand how many tablets or how much gel will equal 15 grams of carbs; half a cup of juice or regular soda; one tablespoon of sugar or honey; and hard candies or jelly beans—read the label to understand how many candies or jelly beans will equal 15 grams of carbs.
2. Wait 15 minutes.
3. Check your blood sugar. 
4. Keep repeating steps one through three until your blood sugar is above 70 milligrams per deciliter (mg/dL). 
5. Once your blood sugar is above 70 mg/dL, eat a small meal or snack to prevent your blood sugar from dropping again.

If you’re experiencing clumsiness, coma, confusion and seizures, then your blood sugar is too low for the 15-15 rule. You may need to use the glucagon product that your healthcare provider prescribed. Glucagon is a naturally occurring hormone that encourages your liver to release glucose (sugar) into the bloodstream.

Since extremely low blood sugar is also linked to low potassium, get medical help right away—even after using your glucagon prescription. You might need hospital observation until your blood sugar and potassium levels reach normal ranges again.

Precautions

What Are Reasons I Shouldn’t Take Humalog?

The manufacturer recommends against using Humalog if the following applies to you:

• Your blood sugar levels are low.
• You have a severe allergic reaction to Humalog or any of its ingredients.

What Other Medications Interact With Humalog?

Use caution with the following medications:

• Medications that raise the risk for low blood sugar, such as sulfonamide antibiotics, such as Bactrim DS (sulfamethoxazole/trimethoprim)
• Medications that lower Humalog’s effectiveness and raise blood sugar levels, such as steroids (e.g., prednisone) and atypical antipsychotics, including Zyprexa (olanzapine) or Seroquel (quetiapine)
• Medications that heighten or dull Humalog’s effects, such as alcohol or lithium
• Medications that hide symptoms of low blood sugar, such as beta-blockers, such as Coreg (carvedilol)

This isn’t a complete list of medications that can interact with Humalog. For more detailed information about medications that interact with Humalog, talk with your pharmacist or healthcare provider.

What Medications Are Similar?

There are many different types of insulin. Humalog is a rapid-acting insulin, which is usually given around mealtime.

Other mealtime insulins include:

• Afrezza (inhaled insulin)
• Apidra (glulisine)
• Aspart products, such as NovoLog and Fiasp
• Human regular insulin products, such as Humulin R, Novolin R, or Myxredlin
• Other lispro products, such as like Admelog and Lyumjev

All of the above insulins are rapid acting except for the human regular insulin products, which are short acting. Compared to rapid-acting insulins that are given within 15 minutes of meals, short-acting insulins are given within 30 minutes of meals. While these two types of insulins are slightly different, these insulins have no differences in achieving blood sugar goals and lessening low blood sugar symptoms.

Additionally, unlike the rapid-acting insulins, some of the short-acting ones—like Humulin R and Novolin R—are available as over-the-counter (OTC) medications, which don’t require a prescription from your healthcare provider. As OTC products, the short-acting insulins might also be less costly than the rapid-acting insulins—even without insurance coverage.

Since all of these insulins are mealtime insulins, they’re not typically used together for diabetes. If you have any questions or concerns, talk with your pharmacist or healthcare provider.

How Can I Stay Healthy While Using Humalog?

In addition to regularly taking or using your medications for diabetes, there are other ways to stay healthy, which include the following:

• Make sure to regularly check your blood sugar and perform next steps depending on the results and your healthcare provider’s recommendations.
• Eat a healthy diet.
• Have a regular exercise routine.
• Work toward achieving a healthy weight.
• Stay hydrated.
• Work with a registered dietitian nutritionist (RD/RDN), specifically one that is a Certified Diabetes Care and Education Specialist (CDCES). RDs/RDNs with a CDECES certification are specially trained to help people with diabetes to successfully manage their condition.

Maintaining a healthy lifestyle can help you have well-controlled blood sugar and prevent diabetes-related complications.