Insulin Rapid: What is it? Types, Optimal Use, Dosage and Recommendations

When eaten, this hormone is released into the bloodstream, helping to move glucose from the food that has been ingested into cells for use as energy.

Insulin therapy aims to mimic the endogenous human insulin secretion pattern.

The rapid absorption and rapid action of RAIs are intended to be close to normal endogenous insulin secretion at mealtime.

In people with type 1 diabetes, the body produces little or no insulin, as the cells that produce insulin have been destroyed by an autoimmune reaction.

Insulin replacement through daily injections is required. In type 2 diabetes, the body can produce insulin, but it does not work as it should. This is often known as insulin resistance.

Lifestyle changes can delay the need for tablets and insulin to stabilize blood glucose levels.

When insulin is required, it is essential to understand that this is only the natural progression of the condition.


Insulin is injected through the skin into the fatty tissue known as the subcutaneous layer. It is not injected into the muscle or directly into the blood.

Insulin absorption varies depending on the part of the body where it is injected.

Insulin is absorbed faster in the abdomen and is used by most people.

Some people can also use the buttocks and thighs.

While it is essential to give each injection in a slightly different location within the same site, it is not advisable to change places without first consulting with your doctor.

Today’s tiny needles and injection devices make injecting insulin much more accessible than most people imagine.

By starting insulin, your doctor will help you adjust to the new routine and task of administering insulin and find the correct dose to lower your blood glucose levels to acceptable levels.

Insulin types

When you take insulin, it works to lower the level of glucose in your blood. When glucose is at its lowest level, the effect of insulin is said to have reached its “peak.”

After this, the effect gradually wears off, and blood glucose levels rise.

The doctor will work with the patient on which type of insulin is best for him.

  • A rapid-acting insulin is clear in appearance and begins to work in 1 to 20 minutes, peaks 1 hour later, and lasts for 3 to 5 hours. You should eat immediately after injecting rapid-acting insulin.
  • Short-acting insulin is clear in appearance. It starts working in half an hour, so you need to inject half an hour before eating, and it peaks in 2 to 4 hours and lasts for 6 to 8 hours.
  • Intermediate-acting insulin has a cloudy appearance and has protamine or zinc added to delay its action. It starts to work about 1 hour and a half after the injection, peaks at 4 to 12 hours and lasts for 16 to 24 hours.
  • Mixed insulin is cloudy and contains premixed combinations of short-acting or rapid-acting insulin and intermediate-acting insulin. This makes the injection easier by administering two types of insulin in one injection. This insulin can be taken before a meal to provide a stable insulin level for a time after the meal.
  • Long-acting insulin is clear in appearance. It usually does not have a pronounced peak and lasts up to 24 hours.

Fast-acting insulin

Rapid-acting insulins work in a narrower and more predictable time frame. Because they work quickly, they are most often used at the beginning of a meal.

Rapid-acting insulin acts like the insulin made by the human pancreas. It quickly lowers the blood sugar level and works for a short time.

By using rapid-acting insulin instead of short-acting insulin at the start of dinner, you can avoid severe drops in blood sugar in the middle of the night.

A rapid-acting insulin is typically an insulin analog.

Because fast-acting insulins work very quickly, they can increase the chances of hypoglycemia. Therefore, care must be taken when dosing.

Some fast-acting insulins

Rapid insulins, a type of insulin known as analog insulins, can be injected or given through an insulin pump.


Humalog is a product with the active ingredient insulin lispro.

It is incredibly fast-acting and will usually start working within 15 minutes.

The effects of insulin last between 2 and 5 hours.

It is faster acting than soluble insulin and, therefore, beneficial with meals.

Like many other forms of rapid-acting insulin, Humalog can be combined with intermediate-acting or longer-acting insulin for a more extended period of blood glucose maintenance.


When Novo rapid is injected, it works extremely fast to normalize blood sugar levels.

It usually starts working after 10-20 minutes and will last 3-5 hours.

It can be injected before a meal and sometimes immediately after to ensure tight control of postprandial levels.

Mealtime can be one of the most challenging times to control blood sugar in people with diabetes.

With each meal, the pancreas releases insulin to help the body use or store blood glucose from food, but people with type 2 diabetes do not respond well to that insulin.

Optimal use of insulin

Rapid-acting insulin can help with meals because it starts working almost immediately, giving the body the insulin it needs to process glucose from food.

However, to maximize your benefits, it is essential to follow these steps:

Follow dosing instructions

To ensure that you get the expected benefits of rapid-acting insulin, it is essential to know precisely when to use it and how to calculate doses correctly.

Most people with diabetes have two options for determining the dose:

A fixed-dose – Your doctor calculates the amount of insulin based on your weight and other health factors. You take this dose before every meal, regardless of what you plan to eat.

Calculated dose for each meal: the amount is based on the number of grams of carbohydrates to be consumed. To determine your dosage, you need to understand the relationship between one unit of insulin and grams of carbohydrate.

For example, for some adults, it may be one unit of insulin for every 10 grams of carbohydrate, while for others, it may be 15 grams. This approach allows you to fine-tune your insulin to your needs and get the correct amount of insulin at each meal.

Application time

Because rapid-acting insulin works much faster than traditional insulin, typically taken 30 minutes before a meal, timing is of the essence.

Rapid-acting insulin starts to work in 5 to 15 minutes and peaks in about 45 minutes; it is recommended to take the insulin when the food plate is in front of you.

You risk having a low blood sugar episode before eating if you take it earlier.

Carbohydrate consumption

Just because insulin can be given to match the number of carbohydrates in your meal does not mean that you should eat as many carbohydrates as you want.

Excess carbohydrates and excess insulin lead to weight gain, undermining diabetes control.

Do not accumulate doses.

When using rapid-acting insulin, it is essential to understand that if you are hungry and want to eat again in a few hours, you may still have insulin in your blood.

When calculating another dose for a snack or meal, you should be aware that you may already have insulin circulating.

It can be helpful at these times to determine if you are at risk of taking more insulin while the previous dose is still active.

Control your blood sugar level

Making sure to check your blood sugar before taking a dose is very important. The results should be recorded.

This will help detect patterns that indicate how your body responds to insulin and your dietary choices.