Insulin Dosages: How to Manage Blood Sugar

Insulin is a hormone that helps regulate metabolism and blood sugar. People with diabetes often need to take insulin injections to stay healthy. That’s because people with type 1 diabetes don’t make insulin, and people with type 2 diabetes don’t respond properly to the insulin their bodies produce. To help manage diabetes, your healthcare provider will likely provide you with an insulin dosage chart or regimen.

This article discusses how insulin dose is calculated, the types of insulin, and how much insulin to take throughout the day. 

Who Needs Insulin Shots?

Many people with diabetes need to take insulin. There’s now a type of inhaled insulin, but most people who need insulin still take insulin shots. Most insulin shots used in the United States are U-100. That means there are 100 units of insulin in each millimeter of the fluid. Knowing this can help you calculate your insulin dose.

Type 1 Diabetes

In nearly all cases, people with type 1 diabetes will need insulin shots. That’s because their body does not naturally produce insulin. Some people with type 1 diabetes use an insulin pump (a device that continuously pumps insulin into the body) to avoid having to give themselves injections multiple times a day.

Type 2 Diabetes

Some, but not all, people with type 2 diabetes need insulin shots. In the past, about 30% of people with type 2 diabetes needed insulin shots. Thanks to advances in medications that manage type 2 diabetes, combined with diet and exercise, not everyone with type 2 diabetes needs insulin.

Types of Insulin

When you’re calculating your insulin dose, there are two types of insulin replacement to consider. Some people need both types, while some need only one or the other:

• Basal insulin replacement: Basal, or background, insulin is the insulin that your body releases throughout the day and overnight that helps keep your blood sugar levels steady. People who inject insulin use about half of their daily insulin dose to replace basal insulin. You can use either long-acting or rapid-acting insulin for basal insulin replacement. 
• Bolus insulin replacement: Bolus insulin is released after meals to help your body process the influx of blood sugar. People with diabetes use bolus insulin replacement before meals or to lower their blood sugar when it gets too high. About half of your daily insulin dosage will consist of bolus insulin. Use rapid-acting insulin for your bolus insulin replacement needs. 

Recommended Dose

The amount of insulin that you need each day is measured in units. The number of units you need each day is known as your total daily insulin requirement. To calculate this, divide your weight in pounds by four. Here’s the equation:

• Total daily insulin requirement (in units) = weight (in pounds)/4

For example, if you weigh 160 pounds, your total daily insulin requirement is 40 units. If you weigh 220 pounds, your total daily insulin requirement is 55 units. However, it is important to note that this is an estimate. Insulin resistance is also an important factor; a person who is more insulin resistant may need more insulin than someone of the same weight.

Once you know your total daily insulin requirement, you can calculate your basal and bolus requirements. The simplest way is to allot half to each. However, your basal insulin requirement can vary between 40%-50% of your total daily requirement.

Your bolus replacement makes up 50%-60%. The amount of insulin you take before each meal will be a percentage of the bolus total. Exactly how much depends on how many carbohydrates you’re eating or your blood sugar before the meal.

Factors That Affect Dosage

The insulin dose calculator described above is a very basic approach. Several factors affect what insulin dosage is right for you, including:

• Your type of diabetes and level of insulin resistance. People with type 1 diabetes don’t make insulin and so may need a higher dose. Some people with type 2 diabetes and more insulin resistance may also need a higher dose of insulin. 
• Your diet: When you’re eating more carbohydrates, you may need more insulin. 
• Exercise increases insulin sensitivity, meaning you may need less insulin if you exercise regularly. 

Chronic health conditions, alcohol use, illness, medications, and your goals for diabetes management all play a role in what insulin dose is right for you. 

Adjusting Dosage Over Time

Figuring out your insulin dose can feel like a major victory. However, it’s important not to be complacent, since insulin dosage needs often change over time because of the following factors:

• Weight gain/loss
• Changes in diet
• Changes in physical activity level
• Illness
• Medication
  

Always talk to your healthcare provider before making any changes to your insulin dosage. 

Summary

Many people with diabetes need to take insulin shots to stay healthy. The number of units of insulin that you need each day is called your total daily insulin requirement. This is estimated by dividing your body weight by 4. While that gives a rough number, other factors including your type of diabetes, level of insulin resistance, diet, and exercise all play a role in calculating your insulin dose. Because of that, it’s important to work with a healthcare provider when developing your insulin regimen. 

A Word From Verywell 

Managing insulin can be intimidating, especially if you or a loved one was recently diagnosed with diabetes. It’s normal to have a bit of a learning curve. If you find yourself frustrated with the process, don’t hesitate to reach out to your healthcare team for guidance.