Humalog Side Effects Center

Last updated on RxList: 8/29/2022
Humalog Side Effects Center

What Is Humalog?

Humalog (insulin lispro [rDNA origin]) Injection is a hormone that is produced in the body used to treat type 1 (insulin-dependent) diabetes in adults. Humalog is usually given together with another long-acting insulin. Humalog is also used together with oral medications to treat type 2 (non insulin-dependent) diabetes in adults.

What Are Side Effects of Humalog?

Common side effects of Humalog include:

  • injection site reactions (e.g., pain, redness, irritation).
  • Low blood sugar (hypoglycemia), is the most common side effect of insulin lispro such as Humalog.
  • Symptoms of low blood sugar may include headache, nausea, hunger, confusion, drowsiness, weakness, dizziness, blurred vision, fast heartbeat, sweating, tremor, trouble concentrating, confusions, or seizure (convulsions).
  • Low blood potassium levels (hypokalemia). Symptoms include dry mouth, increased thirst, increased urination, uneven heartbeats, muscle pain or weakness, leg pain or discomfort, or confusion

Humalog may cause serious side effects including:

  • weight gain,
  • swelling in your hands or feet,
  • feeling short of breath,
  • headache,
  • hunger,
  • sweating,
  • irritability,
  • dizziness,
  • fast heart rate,
  • feeling anxious or shaky,
  • leg cramps,
  • constipation,
  • irregular heartbeats,
  • fluttering in your chest,
  • increased thirst or urination,
  • numbness or tingling, and
  • muscle weakness or limp feeling

Get medical help right away, if you have any of the symptoms listed above.

Seek medical care or call 911 at once if you have the following serious side effects:

  • Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
  • Serious heart symptoms such as fast, irregular, or pounding heartbeats; fluttering in your chest; shortness of breath; and sudden dizziness, lightheartedness, or passing out;
  • Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors.

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

Dosage for Humalog

The total daily insulin requirement varies and the dose is usually between 0.5 to 1 unit/kg/day. Insulin needs may be altered during stress, major illness, or changes in exercise, meal patterns, or co-administered drugs.

What Drugs, Substances, or Supplements Interact with Humalog?

Humalog may interact with albuterol, clonidine, reserpine, guanethidine, or beta-blockers. Many other medicines can increase or decrease the effects of insulin lispro on lowering blood sugar. Tell your doctor all prescription and over-the-counter medications and supplements you use.

Humalog During Pregnancy and Breastfeeding

Tell your doctor if you are pregnant before using Humalog. Discuss a plan for managing blood sugars with your doctor before becoming pregnant. Your doctor may switch the type of insulin used during pregnancy. It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Additional Information

Our Humalog (insulin lispro, USP [rDNA origin]) Injection Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Diabetes is defined best as... See Answer
Humalog Consumer Information

Get emergency medical help if you have signs of insulin allergy: redness or swelling where an injection was given, itchy skin rash over the entire body, trouble breathing, fast heartbeats, feeling like you might pass out, or swelling in your tongue or throat.

Call your doctor at once if you have:

  • weight gain, swelling in your hands or feet, feeling short of breath;
  • low blood sugar--headache, hunger, sweating, irritability, dizziness, fast heart rate, and feeling anxious or shaky; or
  • low potassium--leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling.

Common side effects may include:

  • low blood sugar;
  • weight gain;
  • swelling in your hands or feet;
  • itching; or
  • thickening or hollowing of the skin where you injected the medicine.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Diabetes: What Raises and Lowers Your Blood Sugar Level? See Slideshow
Humalog Professional Information


Observed With HUMALOG U-100

The following adverse reactions are discussed elsewhere:

Clinical Trial Experience

Because clinical trials are conducted under widely varying designs, the adverse reaction rates reported in one clinical trial may not be easily compared with those rates reported in another clinical trial, and may not reflect the rates actually observed in clinical practice.

The frequencies of Treatment-Emergent Adverse Events during HUMALOG clinical trials in patients with type 1 diabetes mellitus and type 2 diabetes mellitus are listed in the tables below.

Table 1: Treatment-Emergent Adverse Events in Patients with Type 1 Diabetes Mellitus (adverse events with frequency ≥5%)

Events, n (%) Lispro Regular human insulin
(n=81) (n=86)
Flu syndrome 28 (34.6) 28 (32.6)
Pharyngitis 27 (33.3) 29 (33.7)
Rhinitis 20 (24.7) 25 (29.1)
Headache 24 (29.6) 19 (22.1)
Pain 16 (19.8) 14 (16.3)
Cough increased 14 (17.3) 15 (17.4)
Infection 11 (13.6) 18 (20.9)
Nausea 5 (6.2) 13 (15.1)
Accidental injury 7 (8.6) 10 (11.6)
Surgical procedure 5 (6.2) 12 (14.0)
Fever 5 (6.2) 10 (11.6)
Abdominal pain 6 (7.4) 7 (8.1)
Asthenia 6 (7.4) 7 (8.1)
Bronchitis 6 (7.4) 6 (7.0)
Diarrhea 7 (8.6) 5 (5.8)
Dysmenorrhea 5 (6.2) 6 (7.0)
Myalgia 6 (7.4) 5 (5.8)
Urinary tract infection 5 (6.2) 4 (4.7)

Table 2: Treatment-Emergent Adverse Events in Patients with Type 2 Diabetes Mellitus (adverse events with frequency ≥5%)

Events, n (%) Lispro
Regular human insulin
Headache 63 (11.6) 66 (9.3)
Pain 77 (10.8) 71 (10.0)
Infection 72 (10.1) 54 (7.6)
Pharyngitis 47 (6.6) 58 (8.2)
Rhinitis 58 (8.1) 47 (6.6)
Flu syndrome 44 (6.2) 58 (8.2)
Surgical procedure 53 (7.4) 48 (6.8)

Insulin Initiation And Intensification Of Glucose Control

Intensification or rapid improvement in glucose control has been associated with a transitory, reversible ophthalmologic refraction disorder, worsening of diabetic retinopathy, and acute painful peripheral neuropathy. However, long-term glycemic control decreases the risk of diabetic retinopathy and neuropathy.


Long-term use of insulin, including HUMALOG, can cause lipodystrophy at the site of repeated insulin injections or infusion. Lipodystrophy includes lipohypertrophy (thickening of adipose tissue) and lipoatrophy (thinning of adipose tissue), and may affect insulin absorption. Rotate insulin injection or infusion sites within the same region to reduce the risk of lipodystrophy [see DOSAGE AND ADMINISTRATION].

Weight Gain

Weight gain can occur with insulin therapy, including HUMALOG, and has been attributed to the anabolic effects of insulin and the decrease in glucosuria.

Peripheral Edema

Insulin, including HUMALOG, may cause sodium retention and edema, particularly if previously poor metabolic control is improved by intensified insulin therapy.

Adverse Reactions With Continuous Subcutaneous Insulin Infusion (CSII) — HUMALOG U-100

In a 12-week, randomized, crossover study in adult patients with type 1 diabetes (n=39), the rates of catheter occlusions and infusion site reactions were similar for HUMALOG U-100 and regular human insulin treated patients (see Table 3).

Table 3: Catheter Occlusions and Infusion Site Reactions

Regular human insulin
Catheter occlusions/month 0.09 0.10
Infusion site reactions 2.6% (1/38) 2.6% (1/39)

In a randomized, 16-week, open-label, parallel design study of children and adolescents with type 1 diabetes, adverse event reports related to infusion-site reactions were similar for insulin lispro and insulin aspart (21% of 100 patients versus 17% of 198 patients, respectively). In both groups, the most frequently reported infusion site adverse events were infusion site erythema and infusion site reaction.

Allergic Reactions

Local Allergy

As with any insulin therapy, patients taking HUMALOG may experience redness, swelling, or itching at the site of the injection. These minor reactions usually resolve in a few days to a few weeks, but in some occasions, may require discontinuation of HUMALOG. In some instances, these reactions may be related to factors other than insulin, such as irritants in a skin cleansing agent or poor injection technique.

Systemic Allergy

Severe, life-threatening, generalized allergy, including anaphylaxis, may occur with any insulin, including HUMALOG. Generalized allergy to insulin may cause whole body rash (including pruritus), dyspnea, wheezing, hypotension, tachycardia, or diaphoresis.

In controlled clinical trials, pruritus (with or without rash) was seen in 17 patients receiving regular human insulin (n=2969) and 30 patients receiving HUMALOG (n=2944).

Localized reactions and generalized myalgias have been reported with injected metacresol, which is an excipient in HUMALOG [see CONTRAINDICATIONS].

Antibody Production

In large clinical trials with patients with type 1 (n=509) and type 2 (n=262) diabetes mellitus, anti-insulin antibody (insulin lispro-specific antibodies, insulin-specific antibodies, cross-reactive antibodies) formation was evaluated in patients receiving both regular human insulin and HUMALOG (including patients previously treated with human insulin and naive patients). As expected, the largest increase in the antibody levels occurred in patients new to insulin therapy. The antibody levels peaked by 12 months and declined over the remaining years of the study. These antibodies do not appear to cause deterioration in glycemic control or necessitate an increase in insulin dose. There was no statistically significant relationship between the change in the total daily insulin dose and the change in percent antibody binding for any of the antibody types.

Postmarketing Experience


The following additional adverse reactions have been identified during post-approval use of HUMALOG. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Medication errors in which other insulins have been accidentally substituted for HUMALOG have been identified during postapproval use [see PATIENT INFORMATION].

Read the entire FDA prescribing information for Humalog (Insulin Lispro (Human Analog))

© Humalog Patient Information is supplied by Cerner Multum, Inc. and Humalog Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

Health Solutions From Our Sponsors