Lantus Side Effects

Generic name: insulin glargine

Medically reviewed by Drugs.com. Last updated on Feb 17, 2025.

Note: This document provides detailed information about Lantus Side Effects associated with insulin glargine. Some dosage forms listed on this page may not apply specifically to the brand name Lantus.

Applies to insulin glargine: subcutaneous solution.

Serious side effects of Lantus

Along with its needed effects, insulin glargine (the active ingredient contained in Lantus) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking insulin glargine:

More common side effects

• blindness
• blurred vision
• cough or hoarseness
• decreased vision
• diarrhea
• dizziness
• fever or chills
• general feeling of discomfort or illness
• headache
• joint pain
• lower back or side pain
• loss of appetite
• muscle aches and pains
• nausea
• nervousness
• painful or difficult urination
• pounding in the ears
• runny nose
• shivering
• slow or fast heartbeat
• sore throat
• sweating
• swelling of the hands, ankles, feet, or lower legs
• trouble sleeping
• unusual tiredness or weakness
• vomiting

Incidence not known

• anxiety
• chest tightness
• cold sweats
• coma
• confusion
• cool, pale skin
• decreased urine
• depression
• depression or thickening of the skin at the injection site
• difficulty swallowing
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• dry mouth
• fast heartbeat
• hives, itching, skin rash
• increased hunger
• increased thirst
• itching, pain, redness, or swelling at the injection site
• large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
• mood changes
• muscle cramps
• nightmares
• numbness or tingling in the hands, feet, or lips
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• seizures
• shakiness
• slurred speech
• trouble breathing
• weight gain

Other side effects of Lantus

Some side effects of insulin glargine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common side effects

• body aches or pain
• diarrhea
• difficulty in moving
• discouragement
• ear congestion
• feeling sad or empty
• irritability
• lack of appetite
• loss of interest or pleasure
• loss of voice
• muscle pain or stiffness
• pain in the arms or legs
• pain in the joints
• pain or tenderness around the eyes and cheekbones
• sneezing
• stuffy or runny nose
• tender, swollen glands in the neck
• trouble concentrating
• voice changes

For healthcare professionals

Applies to insulin glargine: subcutaneous solution.

General adverse events

Adverse reactions associated with insulin glargine (the active ingredient contained in Lantus) include hypoglycemia, allergic reactions, injection site reactions, lipodystrophy, pruritus, rash, edema, and weight gain.^[Ref]

Metabolic

• Very common (10% or more): Hypoglycemia
• Frequency not reported: Weight gain^[Ref]

The ORIGIN (Outcome Reduction with Initial Glargine Intervention) trial, an open-labeled, randomized study comparing insulin glargine (the active ingredient contained in Lantus) to standard care in persons 50 years or older with abnormal glucose levels (impaired fasting glucose and/or impaired glucose tolerance) or early type 2 diabetes mellitus and established cardiovascular (CV) disease or CV risk factors, found over the course of the 6 year study, severe hypoglycemia occurred in 5.7% of patients receiving insulin glargine compared to 1.9% in the standard care group. The median HbA1c values in the insulin glargine group ranged from 5.9% to 6.4% while the HbA1c values in the standard care group ranged from 6.2% to 6.6%. The incidence for all hypoglycemia was 58% and 26% in the insulin glargine and standard groups, respectively.

Weight gain has been reported with insulin therapy and has been attributed to the anabolic effects of insulin and the decrease in glucosuria. In the ORIGIN trial, the median change in body weight from baseline to the last treatment visit was 2.2 kg greater in the insulin glargine group (+1.4 kg vs -0.8 kg).^[Ref]

Local

• Common (1% to 10%): Injection site reactions, injection site pain
• Postmarketing reports: Localized cutaneous amyloidosis at the injection site^[Ref]

Injection site reactions include redness, pain, itching, hives, swelling, or inflammation. In some cases, these reactions may be caused by other factors, such as irritants in skin cleansing agents. In clinical studies, there was a higher incidence of treatment-emergent injection site pain in insulin-glargine treated patients compared to NPH-treated patients (2.7% vs 0.7%). Localized cutaneous amyloidosis at the injection site has occurred and hyperglycemia has been reported with repeated insulin injections into areas of localized cutaneous amyloidosis. Hypoglycemia has been reported with a sudden change to an unaffected injection site.^[Ref]

Hypersensitivity

• Rare (less than 0.1%): Allergic reactions^[Ref]

Hypersensitivity side effects have included both local and systemic reactions. Anaphylaxis has been reported. Local reactions have presented as erythema, local edema, and pruritus at the injection site. Most minor reactions to insulin at the injection site resolve in a few days to a few weeks.^[Ref]

Other

• Postmarketing reports: Medication errors

Medication errors, in which other insulins, particularly rapid-acting insulins, have been accidentally administered instead of this insulin, have been reported.

Cardiovascular

• Very common (10% or more): Hypertension (up to 19.6%)
• Common (1% to 10%): Peripheral edema^[Ref]

Insulin may cause sodium retention and edema, especially as metabolic control is improving. The ORIGIN (Outcome Reduction with Initial Glargine Intervention) trial, an open-labeled, randomized study in persons 50 years or older with abnormal glucose levels (impaired fasting glucose and/or impaired glucose tolerance) or early type 2 diabetes mellitus and established cardiovascular (CV) disease or CV risk factors, found the time to first occurrence of a major adverse cardiovascular event (MACE) and the incidence of MACE to be similar between insulin glargine (the active ingredient contained in Lantus) and standard care (n=12.537).^[Ref]

Dermatologic

• Common (1% to 10%): Lipohypertrophy
• Uncommon (0.1% to 1%): Lipoatrophy
• Postmarketing reports: Rash urticaria^[Ref]

Postmarketing reports indicate children and adolescents may experience more skin reactions such as rash and urticaria, than adults.^[Ref]

Oncologic

• Frequency not reported: Cancer occurrence^[Ref]

The ORIGIN (Outcome Reduction with Initial Glargine Intervention) trial, an open-labeled, randomized study in persons 50 years or older with abnormal glucose levels (impaired fasting glucose and/or impaired glucose tolerance) or early type 2 diabetes mellitus and established cardiovascular (CV) disease or CV risk factors, comparing insulin glargine to standard care found the overall incidence of all types of cancer combined or death from cancers was similar between treatment groups (n=12,537). In July 2009, The US FDA reported on an ongoing safety review evaluating a possible increased risk of cancer. In February 2011, the FDA in an updated communication reported the evidence was inconclusive and it is not possible to conclude that the use of this insulin increases the risk of cancer.^[Ref]

Immunologic

• Frequency not reported: Antibody formation^[Ref]

As with all therapeutic proteins, the potential for immunogenicity exits. The detection of antibody formation is highly dependent on the sensitivity and specificity of the assay and may be influenced by assay methodology, sample handling and collection, concomitant medications, and underlying disease. The presence of insulin antibodies may increase or decrease the efficacy of insulin and may require dose adjustment.^[Ref]

Ocular

• Rare (less than 0.1%): Visual impairment, retinopathy^[Ref]

Rapid improvement in glucose control has been associated with a transitory, reversible ophthalmologic refraction disorder and worsening of diabetic retinopathy. However, long-term glycemic control decreases the risk.^[Ref]

Gastrointestinal

• Common (1% to 10%): Gastroenteritis^[Ref]

Musculoskeletal

• Rare (less than 0.1%): Myalgia^[Ref]

Nervous system

• Common (1% to 10%): Headache
• Very rare (less than 0.01%): Dysgeusia
• Frequency not reported: Peripheral neuropathy^[Ref]

Rapid improvement in glucose control has been associated with a transitory, reversible acute painful peripheral neuropathy. However, long-term glycemic control decreases the risk.^[Ref]

Respiratory

• Very common (10% or more): Upper respiratory infection (up to 22.4%)
• Common (1% to 10%): Pharyngitis, rhinitis, sinusitis^[Ref]

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Further information

Lantus side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer