What is Lantus (Insulin Glargine)?

Lantus is a long-acting insulin that helps blood glucose get into the cells for energy. Lantus is the brand name of insulin glargine. Insulin glargine works by lowering high blood glucose levels in people with diabetes. It replaces the insulin we naturally make. Insulin is a natural hormone that helps our body to convert glucose into energy and store glucose in the form of glycogen for later use. People who are diabetic cannot make enough insulin or use it properly. As a result, glucose cannot be used or stored properly, which leads to a build up of glucose in the bloodstream. Injecting insulin glargine can help lower blood glucose to normal level. This medication is used to treat type 2 diabetes in adults and type 1 diabetes in adults and children who have reached the age of 6 years.

Lantus onset, peak time and duration

Lantus or insulin glargine refers to a man made hormone that is naturally produced in the body. This medication is used to treat both type 1 and type 2 diabetes. Lantus onset refers to how quickly insulin glargine starts to work in the body. As a long acting insulin, the medication onset is about one and a half hours and can last up to 24 hours.

The drug peak refers to how long it takes before this medication achieves the maximum effects in the body. The lantus peak is 6 hours. Insulin glargine is a part of a treatment program that includes diet, exercise, weight control and testing your blood glucose. Make sure you follow the program as it is instructed by your doctor


Lantus should be stored in its original container and kept away from heat and light. You are not supposed to freeze this medication. In case of frozen lantus, you should throw it away. Ask your doctor how to properly dispose the medication. Do not use this medication incase it looks cloudy or has particles in it.

How to take insulin glargine?

Insulin glargine is injected subcutaneously once every day. Your doctor will show you how to inject this medication at home. You should not use this medication if you do not understand how to properly inject it. Make sure you rotate the injection site to avoid adverse reactions. You are not supposed to inject insulin glargine into a muscle or vein.


The dosage will vary depending on your lifestyle and results your doctor will find after monitoring your blood glucose. To help you remember your dosage, you should take this medication at the same time every day. Your doctor may change your dosage if you have an acute illness, during changes in meal patterns or physical activity. Use insulin glargine as it is prescribed by your doctor. You should not use larger or smaller amounts of lantus than what is recommended. You should not stop taking this medication without consulting with your doctor. In case you missed a dose you should take it as soon as you remember. Avoid taking a double dose to make up for the missed dose. If the next dose is near, skip the missed dose and continue with normal dosing.

Side effects

Low blood sugar or hypoglycemia is the most common side effect of using lantus.

Symptoms of hypoglycemia include

  • fast heartbeat
  • headache
  • sweating
  • difficulty concentrating
  • fainting
  • seizure
  • hunger
  • weakness

You can quickly relieve these symptoms with a fast acting carbohydrate such as non diet soda, fruit juice or hard candy.

Other side effects include allergic reactions with symptoms such as

  • redness
  • itching
  • difficulty breathing
  • swelling

Disclaimer: Please note that the contents of this community article are strictly for informational purposes and should not be considered as medical advice. This article, and other community articles, are not written or reviewed for medical validity by Canadian Insulin or its staff. All views and opinions expressed by the contributing authors are not endorsed by Canadian Insulin. Always consult a medical professional for medical advice, diagnosis, and treatment.