Available in the form of injection, Lantus is the brand-name for insulin glargine – a man-made form of long-acting insulin that helps to lower and/or manage blood glucose levels in adults with type 1 or type 2 diabetes and children (6 years and older) with type 1 diabetes.

What is Insulin and How Does It Work?

For those who do not know, insulin is a natural hormone produced in the body, by the pancreas, after we eat something. It is in the presence of this hormone that the body uses the carbohydrates present in the food for energy and to convert and store the excess in the cells, in form of glucose, for later use.

People whose bodies fail to produce or utilize the insulin (patients of diabetes) often need to take a form of human insulin to lower and maintain their blood glucose levels.

Human or manufactured insulin is available in different types, varying according to their onset and peak time as well as the total duration their effects last for. As classified by the Food and Drug Administration, here are the five types of man-made insulin:

  1. Rapid-acting insulin
  2. Short-acting insulin
  • Intermediate-acting insulin
  1. Long-acting insulin
  2. Pre-mixed insulin (a combination of rapid or short-acting insulin and long-acting insulin)

While our bodies experience a sugar rush after eating and hence, insulin is needed to prevent the blood glucose level from rising too high, we also need small amounts of the hormone between meals to maintain blood sugar.

This is where the long-acting form of manufactured insulin comes in!

Long-Acting Insulin

As the name suggests, long-acting insulin helps to maintain blood sugar for a considerably longer period than the other types – it can help keep the blood glucose level within a healthy range for up to 24 hours. It also has longer onset and peak times.

Since it continues to work throughout the day, unlike the other types that only help to lower sugar levels after eating, long-acting insulin is also known as background or basal insulin.

The mechanism of action of long-acting insulin is similar to that of the naturally produced hormone. Three different types of long-acting insulin are currently available:

  1. Insulin detemir – lasts for 18 to 23 hours
  2. Insulin glargine – lasts for up to 24 hours
  • Insulin degludec – lasts for up to 42 hours

Lantus – A Product of Insulin Glargine

Lantus is the brand name for insulin glargine injections that (as mentioned earlier) are used to treat hyperglycemia caused by type 1 and type 2 diabetes in adults and by type 1 in pediatric patients.

Since people with type 1 diabetes primarily rely on exogenous insulin supply to maintain their blood glucose level, insulin injections, like Lantus, are generally used as the first line of medications. However, they are not the first choice for the treatment/management of type 2 diabetes. Patients of type 2 diabetes are prescribed with insulin in the later stages when the oral medications lose efficiency or the pancreatic cells get so damaged that they cannot produce the hormone anymore.

Lantus Mechanism of Action

Manufactured by using the recombinant DNA technology, the mechanism of action of this type of long-acting insulin is similar to that of the natural hormone.

It helps to lower and manage blood sugar by regulating the process of glucose metabolism that includes stimulating the uptake of glucose, particularly by fat and skeletal muscles, as well as inhibiting the hepatic production of glucose. The insulin also enhances protein synthesis and inhibits proteolysis and lipolysis; the processes for the breakdown of protein and fats (and other lipids) respectively.

How Protein Levels Are Linked with Blood Sugar?

In the body of a healthy (non-diabetic) person, the higher levels of amino acids (as a result of protein breakdown) signal the pancreas to produce insulin and glucagon. Insulin initiates the uptake of amino acids by the muscle cells, whereas glucagon signals the liver to release stored sugar. As a result, the level of blood sugar remains stable after the consumption of protein.

However, the process is disrupted in people with type 1 diabetes. While the pancreas does not produce insulin, it produces glucagon as soon as the level of amino acids increases in the blood, which then stimulates the release of stored sugar by the blood. When there is no insulin to utilize the sugar, the blood sugar level rises.

The increase in blood sugar would be much lesser with protein consumption than it would be with the use of an equivalent amount of carbohydrates. However, diabetic patients are likely to need additional insulin dosage after consuming a generous portion of protein, such as a large steak.

Limitations of Use

Lantus is not meant to be used for treating type 1 diabetes in children under the age of six and type 2 diabetes in children of any age. It shouldn’t be used for the treatment of diabetic ketoacidosis as well.

Available Dosage Forms and Strengths

The injections of Lantus contain 100 units/ml of insulin glargine and are available as:

  • 3 ml SoloStar prefilled pen for single-patient-use.
  • 10 ml vial for multiple doses.


Lantus can be stored for up to 28 days either in the refrigerator or at room temperature. However, just like other types of insulin, it should never be stored in the freezer; discard if it has been frozen.

Also, protect the insulin from direct light and heat.

The unopened pens/vials can be stored in the refrigerator between 36 to 46 degrees Fahrenheit (2-8 degrees centigrade) until the expiration date.

Recommended Dosage of Lantus

The right dosage of Lantus varies across patients because it depends on several factors and may need to be adjusted with certain changes, for example with changes in diet or physical activity, in case of an illness, and/or with changes in hepatic or renal function.

Determining the right dosage for a patient, in the first place, requires considering the type of diabetes, its severity, other health conditions the patient may be suffering from, any other medication a person is taking, health history, and the glycemic control goal.

Initial Dosage

Here is the generally initial recommended dosage of Lantus:

For Type 1 Diabetes

People with type 1 diabetes are generally prescribed to fulfill one-third of their daily insulin requirement with Lantus, in the beginning. The remaining two-third amount of required insulin is taken in the form of a short-acting one, before a meal.

Simply put, people with type 1 diabetes are generally treated with a combination of short-acting and long-acting insulins.

For Type 2 Diabetes

The recommended starting dose of Lantus for patients of type 2 diabetes, who are being treated with insulin for the first time, is 0.2 units per kg or a maximum of up to 10 units per day.

The amount and time of dosage of other anti-diabetic drugs may need to be adjusted with the beginning of treatment with Lantus.

How to Use Lantus?

Lantus should be administered subcutaneously in thigh, abdominal area, or deltoid, once daily. While there is no specific time to take the insulin, it should be taken at the same time every day, once you start it.

Here are some important instructions that you should remember while being treated with Lantus:

  • Always inspect the insulin injections before using. The solution should be colorless and clear and should not have any visible particles; do not use Lantus, or any other insulin, if it has a particulate matter or has discolored.
  • Rotate the site of injection within the same region every day to reduce the risk of lipodystrophy – a medical condition characterized by the abnormal distribution of fat in the body.
  • Administer Lantus at the same time every day.
  • Do not mix or dilute Lantus with any other type of insulin or drug.
  • Never administer the insulin via an insulin pump or intravenously.

Warnings and Precautions

  • Never share your Lantus cartridge or pen with anyone; sharing needles and injections is the leading cause for the spread of lethal diseases, like hepatitis and HIV.
  • Do not switch the type of insulin you are using unless prescribed by a doctor, even if both are insulin glargine. This is because not all brands of insulin glargine are equal and may need dosage adjustments while switching from one brand to another. Similarly, always consult your doctor before changing the type, strength, or dosage of insulin.
  • Treatment of diabetes generally requires making certain dietary and lifestyle changes along with taking the medications for effective results. Follow all the directions given by your doctor with regards to diet, physical activity, and medication to keep your blood glucose levels under control.
  • Do not use Lantus if you have diabetic ketoacidosis or experiencing an episode of hypoglycemia.

Possible Side Effects of Lantus

While Lantus is considered a safe and effective type of insulin for diabetic treatment and hence, is widely used, some people may experience a few negative effects with its usage.

Common Side Effects of Lantus

Here are some of the common side effects associated with Lantus use[1]:

  • Hypoglycemia – low blood sugar
  • Hollowing and/or thickening of the skin on the injection site(s).
  • Mild rash or itching on skin
  • Blurred vision
  • Anxiety
  • Cold sweats
  • Chills
  • Difficulty in thinking
  • Pale and/or cool skin
  • Increased heart rate
  • Nausea
  • Headache
  • Restless sleep
  • Slurred speech
  • Excessive hunger
  • Drowsiness
  • Weakness or unusual fatigue
  • Slurred speech
  • Feeling lightheaded or dizzy

Rare Side Effects of Lantus

Immediately seek medical help if you experience any of the following effects with the use of insulin glargine:

  • Shortness of breath
  • Excessive sweating
  • Quick weight gain without any apparent reason
  • Swelling of feet and/or hands
  • Allergic reaction to the drug – symptoms include redness and/or swelling at the injection site, troubled breathing, skin rash and itchiness all over the body, fast heartbeat, swelling of the throat and/or tongue, having a feeling that may faint.
  • Low potassium – signs include constipation, leg cramps, increased urination and/or thirst, irregular heartbeat, muscle weakness, tingling or numbness in the body, fluttering in the chest

Possible Drug Interactions of Lantus

Any medication that affects your blood sugar or alters the effects of insulin can interact with Lantus. Therefore, it is highly important to tell your doctor about all the medicines that you are taken to overrule the possibility of any adverse interaction. In particular, tell your doctor if you are using:

  • Any other anti-diabetic medication
  • Corticosteroids, such as prednisone
  • Birth control pills
  • Thyroid medications
  • Anti-psychotic medications, such as olanzapine, and clozapine
  • Anti-depressants, particularly monoamine oxidase inhibitors (MAOIs) and fluoxetine
  • Blood pressure medications, including ACE-inhibitors, clonidine, beta-blockers, and diuretics or water pills
  • Pioglitazone or rosiglitazone, sometimes present in combinations with glimepiride or metformin
  • Certain antibiotics, including sulfa drugs

Prescription Assistance for Lantus

Eligible patients can benefit from Copay Savings program run by Sanofi Patient Connection. Click here to check the eligibility criteria for the program or here to fill out the application form, if you know that you qualify for it.

In case you need more information or help regarding the process, call 855-984-6302 between 8 am – 8 pm ET, Monday to Friday.

[1] https://www.drugs.com/sfx/lantus-side-effects.html