Metabolic Health

Know About Insulin for People With Diabetes

Reviewed by

Shifa Fathima

Insulin is a hormone produced in the body by the beta cells in the pancreas. The main function of insulin is to keep blood sugar levels within the normal range. Insulin is responsible for absorbing glucose from the bloodstream into various tissues in the different organ systems. When there is a shortage of insulin, the blood sugar level in the bloodstream, i.e., the glucose builds up, and the tissue does not get enough glucose to convert into energy. 

In type 1 diabetes, the pancreatic cells do not produce insulin. So, insulin is required to be injected into the body regularly. This is for basic survival because the body cannot function without insulin. However, on the other hand, in type 2 diabetes, the insulin produced in the body is not sufficient. Thus, insulin injections are needed to manage blood sugar levels. 

Starting on Insulin for Diabetes

Depending on the type of diabetes and severity, 4-5 insulin injections in a day may be necessary. For type 1 diabetes, usually, a pump is used to deliver insulin into the body. A new cannula is inserted under the subcutaneous layer of the skin every 2-3 days. Through the cannula, the insulin pump delivers the insulin into the bloodstream. However, for type 2 diabetes, if it is not too severe, simple changes in the diet, physical activity, and tablets can maintain the blood sugar levels. If tablets are not enough, getting started on insulin injections may become necessary. 

If insulin for diabetes must be started, your doctor will explain the following:

  • Types of insulin
  • When, where, and how to inject insulin?
  • How to rotate sites of injection?
  • How to store insulin?
  • What to do when blood sugar levels drop?
  • How to record blood sugar level and insulin dose?

Types of Insulin for diabetes

There are five types of insulin for diabetes. These groups are categorised based on their reaction time in the body. The doctor suggests a specific type of insulin based on various factors and the patient's medical history. 

The five main types of insulin are: 

  • Rapid-acting insulin
  • Short-acting insulin
  • Intermediate-acting insulin
  • Mixed insulin 
  • Long-acting insulin 

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Insulin Injection Devices

Various types of insulin delivery devices are available. The most common ones are syringes, insulin pumps, and insulin pens. Insulin syringes are typically manufactured in standard sizes – 0.3 ml or 30 units, 0.5 ml or 50 units, and 1.0 ml or 100 units. The syringe size essentially depends on the dosage of insulin for diabetes. The needles for the syringes are available in sizes ranging from 6 mm to 8 mm. Insulin syringes are usually of the single-use type. Insulin pens are more convenient.  

Insulin pens are either disposable or reusable. Disposable pens have an in-built cartridge which is discarded when empty. They also need to be disposed of when they have not been stored in the refrigerator for more than a month or when the expiry date has passed. 

Insulin pumps, on the other hand, are worn outside the body. It is pre-programmed, which holds a specified quantity of insulin. The pump delivers the insulin to the fatty tissues in the body, generally the abdomen region, through an infusion set. It is a thin plastic tube. The insulin pump is used only for rapid-acting insulin. The infusion set is changed every 2-3 days.  

Insulin Diabetes Injection Sites

Insulin is usually injected into the fatty tissues of the body, called the subcutaneous layer. The abdomen is the most common region where the insulin is injected, as it absorbs the insulin quickly. 

Factors That Speed-up Insulin Absorption

Some factors which speed up insulin absorption are – injecting insulin into a highly mobile area (arms or thighs), high temperature (due to a hot shower, sauna, etc.), and massaging the area around the site of injection (for increased circulation). 

Factors That Delay Insulin Absorption

Some factors that delay insulin absorption are – lipohypertrophy (using the same injection site too frequently), cold insulin (if taken from the refrigerator), and smoking cigarettes. 

Disposal of Used Insulin Syringes

Disposal of syringes, pen needles, lancets, cannulas, insulin containers, etc., must be done carefully in puncture-proof containers with a secure lid. The procedure of disposal varies from country to country. 

Insulin Storage

The storage of insulin is very crucial. Unopened insulin bottles must be stored in the refrigerator on its side. The temperature for storing insulin must be maintained between 2°C and 8°C. Insulin must never be frozen or defrosted. Once the container or vial of insulin is opened, it should be kept at room temperature (around 25°C) and must be used within a month. It also needs to be disposed of safely. It is advised never to expose insulin to direct sunlight. Extreme temperatures affect insulin. 

Insulin Diabetes Safety

Insulin must not be used if it looks cloudy, has any deposits, flakes, or lumps, is beyond its expiry date, is frozen, is kept open at room temperature for more than a month, or is exposed to high temperatures. 

Record Your Blood Glucose Levels and Insulin Doses

A record of blood glucose levels and insulin doses is recommended as it helps keep track and adjust the insulin dose as required. 


Insulin is responsible for absorbing glucose from the bloodstream into various tissues in the organ systems. blood sugar level in the bloodstream increases when there is a shortage of insulin. Insulin is required to bring it back to normal levels. 

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