All About Insulin
Editor’s Note: People who take insulin require consistently affordable and predictable sources of insulin at all times. If you or a loved one are struggling to afford or access insulin, click here.
Insulin is a hormone produced in the pancreas that regulates the amount of glucose in the blood, effectively turning food into fuel for the body. A person is diagnosed with diabetes once the body is no longer able to produce insulin (type 1 diabetes, caused by an autoimmune attack) or able to produce enough insulin (type 2 diabetes, caused by metabolic disorder) to regulate blood sugar levels in a healthy way. Diabetes can develop at any age, and can even happen just during pregnancy (known as gestational diabetes).
A brief history of insulin
In 1921, Frederick Banting and his assistant Charles Best discovered how to remove insulin from a dog’s pancreas. They then used the insulin to save the lives of other animals, and eventually humans with diabetes. Before insulin was discovered, people with diabetes were placed on a “starvation diet,” which just delayed death.
Insulin from cattle and pigs was used for many years, but it caused allergic reactions in many patients. The first synthetic “human” insulin was produced in 1978 utilizing E. coli bacteria in its production. In 1982, Eli Lilly began selling Humulin R/Regular and N/NPH, the first commercially sold biosynthetic human insulins.
Insulin Today
Insulin now comes in many forms. It is important to know the difference and to be aware of the various qualities that set them apart. If you are switching types of insulin because of insurance coverage, cost, or provider recommendation, it is important to learn the differences so that you know how to accurately dose your insulin and stay safe.
There are several types of insulin today: Rapid-acting, Short-acting, Intermediate acting, Long-acting, Ultra Long-Acting and Inhaled insulin. They are categorized by how quickly they begin to work in the blood stream and also how long their effects will last.
They are produced by several companies, including what is known as “The Big Three” in the US: Eli Lilly, Novo Nordisk and Sanofi. Other companies such as Mannkind also sell insulin in the US market. Each company has their own brand of insulin within each of the categories below.
For many people, insulins within the same category (rapid-acting, etc.) can be interchangeable, but this is not true for all. It is important to work with your healthcare provider to determine the right insulin for you.
Editor’s note: visit our US Healthcare Glossary for a deeper dive on the healthcare coverage system in the US.
A note on biosimilars
Biosimilar insulins, the generic form of the biosynthetic insulins currently on the market, are becoming more available as FDA approval pathways are streamlined within the US. It is currently unclear as to whether or not the availability of biosimilars will decrease the cost of insulin in the US.
Several manufacturers in the US are currently offering “generic” versions of their current insulins at a lower price. Other biosimilar companies may begin to enter the US market within the next few years.
Ultra rapid-acting insulin
- Currently comes in two forms:
- Fiasp (bolused or injected)
- Afrezza (inhaled)
- Taken as a bolus or inhaled before or during a meal or to correct for high blood glucose
- Takes effect in 15 minutes
- Fiasp lasts two to four hours, Afrezza lasts one and a half to three hours
- Brand names: Lyumjev (lispro-aabc), Fiasp (aspart, with Vitamin B3 to make it ultra rapid), Afrezza (inhaled)
Rapid-acting insulin
- Taken as a bolus before or during a meal or to correct for high blood glucose
- Takes effect in 15 minutes
- Lasts two to four hours
- Brand names: Apidra (glulisine), Humalog (lispro), Admelog (lispro), Novalog, or Novorapid (aspart)
Short-acting insulin
- Taken as a bolus before or during a meal or to correct for high blood glucose
- Takes effect in 30 minutes
- Lasts three to six hours
- Brand names: Humulin R (insulin Regular human), Novolin R (insulin Regular human)
Intermediate-acting insulin
- Usually taken twice a day as a combination bolus and basal insulin
- Takes effect in two to four hours
- Lasts 12 to 18 hours
- Brand names: Humulin N (Insulin NPH), Novolin N (Insulin NPH)
Long-acting insulin
- Taken once or twice a day as a basal insulin
- Takes effect in two to four hours
- Lasts 24 hours
- Brand names: Lantus (glargine), Levemir (detemir), Basaglar (glargine)
Ultra long-acting insulin
- Taken once a day as a basal insulin
- Takes effect in six hours
- Lasts 36 hours
- Brand names: Toujeo (glargine), Tresiba (degludec)
