Without insulin, the body is unable to utilize sugar present in the bloodstream for energy. Just as it's important to have the right key to unlock a door, it's important to use the right insulin to unlock cells so available sugar can be used.

 

As with most aspects of managing your diabetes, there can be both similarities and differences in the way individuals react to various kinds of insulin. Seek your doctor's advice before making any additions or changes to your regimen.

 

Until recently, most insulin was made from the pancreases of pigs or cattle. More common now are synthetic versions, genetically engineered and structurally identical to that made by a functioning human pancreas. Because insulin is a protein destroyed by digestive enzymes, it must be taken by injection, although some inhaled forms are now being evaluated for their efficacy.

 

All insulin comes dissolved or suspended in liquids, but the solutions have different strengths. In the United States, the most commonly used strength is U-100. That means there are 100 units of insulin per milliliter of fluid. Other strengths are available but are rarely used in the United States. Make sure that you understand the difference when traveling abroad.

Insulin is produced in different strengths and a variety of types, each classified according to how fast it begins to work, how long until its action reaches its peak, and how long the effect lasts.

Insulin Type	Action Begins	Peak	Duration
Humalog®	5 minutes	1 hour	2-4 hours
Regular Insulin	15-30 minutes	2-4 hours	4-6 hours
NPH	30-60 minutes	4-8 hours	20-22 hours
Lente	60 minutes	9-12 hours	22-24 hours
UltraLente®	1-2 hours	9-15 hours	24-26 hours
Lantus®	1.1 hours	No pronounced peak	24+ hours

Some types of insulin can be combined in a single syringe, or purchased pre-mixed to decrease the number of injections necessary. Other types must be injected individually. Talk to your doctor or diabetes educator to determine what types are best for you and whether they can be mixed or must be injected separately to achieve maximum effectiveness.

Humalog (manufactured by Lilly) and Novolog® (manufactured by Novo Nordisk) are the quickest acting types of insulin. Their rapid onset makes Novolog and Humalog ideal for those who count carbohydrates and cover their meals and snacks with injections. The FDA has approved Novolog for use in insulin pumps.

Lilly and Novo Nordisk also manufacture short-acting insulin, commonly referred to as Regular Insulin, which generally takes anywhere from thirty minutes to two hours to begin acting and continues working for four to six hours.

Intermediate range insulin is also made by Lilly and Novo Nordisk. Whether referred to by the brand names of Humulin® and Novolin®, or the generic NPH and Lente, this type takes longer to begin acting, has a longer peak, and remains working in the body longer than Regular, Novolog or Humalog. Both NPH and Lente are used when long-range coverage is desired.

Lantus (manufactured by Aventis) and Humulin UltraLente (manufactured by Lilly) are newer forms. Both UltraLente and Lantus are designed for use as basal insulin, meaning that they provide coverage for the small, continuous need for insulin rather than the additional bursts needed when food is digested.

 

Body weight, activity level, food eaten, illness, stress, and insulin sensitivity (or resistance) all contribute to the complex equation determining how much insulin is needed by an individual at a specific time. As factors in your lifestyle change, it's likely that your needs will vary. Be sure to consult with your healthcare professional before making any changes to your regimen.

 

 

Beaser, R.S., & Hill, J.V. The Joslin Guide to Diabetes: A Program for Managing Your Treatment. New York, Simon & Schuster, 1995.

Cleveland Clinic. (reviewed 2003). What are the different types of insulin? Retrieved August 25, 2003, from www.clevelandclinic.org/health/health-info/docs/3300/
3376.asp?index=11452.