Lantus Side Effects
Generic name: insulin glargine
Medically reviewed by Drugs.com. Last updated on Jun 14, 2022.
Note: This document contains side effect information about insulin glargine. Some of the dosage forms listed on this page may not apply to the brand name Lantus.
For the Consumer
Applies to insulin glargine: subcutaneous solution
Side effects requiring immediate medical attention
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:
- blurred vision
- cough or hoarseness
- decreased vision
- fever or chills
- general feeling of discomfort or illness
- joint pain
- lower back or side pain
- loss of appetite
- muscle aches and pains
- painful or difficult urination
- pounding in the ears
- runny nose
- slow or fast heartbeat
- sore throat
- swelling of the hands, ankles, feet, or lower legs
- trouble sleeping
- unusual tiredness or weakness
Incidence not known
- chest tightness
- cold sweats
- cool, pale skin
- decreased urine
- 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
- numbness or tingling in the hands, feet, or lips
- puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
- slurred speech
- trouble breathing
- weight gain
Side effects not requiring immediate medical attention
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:
- Body aches or pain
- difficulty in moving
- ear congestion
- feeling sad or empty
- 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
- stuffy or runny nose
- tender, swollen glands in the neck
- trouble concentrating
- voice changes
For Healthcare Professionals
Applies to insulin glargine: subcutaneous solution
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]
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 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]
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]
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]
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.
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]
Very common (10% or more): Hypertension (up to 19.6%)
Common (1% to 10%): Peripheral edema[Ref]
Common (1% to 10%): Lipohypertrophy
Uncommon (0.1% to 1%): Lipoatrophy
Postmarketing reports indicate children and adolescents may experience more skin reactions such as rash and urticaria, than adults.[Ref]
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]
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]
Frequency not reported: Antibody formation[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]
Rare (less than 0.1%): Myalgia[Ref]
Common (1% to 10%): Headache
Very rare (less than 0.01%): Dysgeusia
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]
Very common (10% or more): Upper respiratory infection (up to 22.4%)
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More about Lantus (insulin glargine)
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Related treatment guides
1. "Product Information. Lantus (insulin glargine)." Aventis Pharmaceuticals (2001):
2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
3. Cerner Multum, Inc. "Australian Product Information." O 0
4. "Product Information. Toujeo SoloStar (insulin glargine)." sanofi-aventis (2015):
5. "Product Information. Basaglar (insulin glargine)." Eli Lilly Canada Inc (2018):
6. FDA. U.S. Food and Drug Administration "FDA Drug Safety Communication: Update to ongoing safety review of Lantus (insulin glargine) and possible risk of cancer. http://www.fda.gov/Drugs/DrugSafety/ucm239376.htm." (2015):
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Some side effects may not be reported. You may report them to the FDA.