GMO Insulin: What You Need to Know

Most of the insulin used by people today is made by bacteria that have been genetically modified to produce insulin that is identical to insulin made in the human pancreas, according to the National Library of Medicine. That means that insulin is, technically, a genetically modified organism (GMO) product.

Though many people have concerns about GMO products and seek out GMO-free foods and personal care items, experts unanimously agree that GMO insulin is safe and superior to other forms of insulin. For most people, it’s the best option to manage their diabetes.

It's been four decades since the first GMO insulin, a synthetic version of the human hormone insulin, was produced. This was a significant improvement over the insulin harvested from cows and pigs, says the American Diabetes Association (ADA). In the past decades, insulin manufacturers have learned how to modify GMO insulin so that it acts more slowly or quickly, considerably improving patients’ flexibility in diabetes management.

Insulin Basics

Insulin is a protein made in the pancreas that helps your body process sugar, turning the sugar in your blood, known as glucose, into the energy your cells need to function. But not everyone's body produces the needed amount of insulin.

If you have type 1 diabetes, your body can't make insulin, so you need insulin from another source to survive. If you have type 2 diabetes, your body may eventually have trouble making insulin. If this happens, you may need to use insulin as a medicine, too, says the Joslin Diabetes Center.

Development of GMO Insulin

Before the discovery of insulin, people who were struck with type 1 diabetes did not have long to live. Scientists and doctors recommended fasting and calorie-restrictive diets, but there was no real treatment available. Then came the discovery of insulin in 1922. At first, those with diabetes were given insulin from pork (porcine) or cow (bovine) sources, says Rohit Moghe, PharmD, a spokesperson for the American Association of Diabetes Educators. The insulin was extracted from the pancreas of those animals.

Animal insulin could save lives, but the human body recognized that it was not a real human protein, leading to allergic reactions and rejection, says the ADA. This made it hard for some people to use insulin from pigs or cows, Dr. Moghe says, and eventually spurred the development of genetically modified insulin — variously called GMO insulin, genetically engineered insulin, synthetic insulin, human insulin, or recombinant DNA insulin.

The first GMO insulin product developed and approved was Humulin, which was licensed for human use in 1982. A man-made insulin product, Humulin replaces the insulin the body would normally make on its own.

Genetically engineered insulin is made from yeast or a bacteria such as E. coli. In this process, a small piece of DNA, called a plasmid, is removed from the bacteria or yeast cell. The gene for human insulin is then inserted in the plasmid. This is considered genetic modification.

The genetically modified plasmid becomes part of a new bacteria or yeast cell. It is this cell that starts to make insulin, according to an article in Endocrine Reviews.

Benefits of GMO Insulin

Human insulin produced by GMO bacteria has many advantages over the older generation of insulin.

"This form of insulin could then be replicated, mass-produced, and altered to make insulin to be injected around mealtime or formulated in a way that has an extended duration of action," Moghe says. "This has made managing diabetes easier because there are now insulins that people with diabetes can use right before they eat or when they start to eat. They now don't need to take insulin 30 or 45 minutes before a meal, which was once the only option."

Not only is GMO insulin safe, he says, but it's easier to make on a large scale than porcine or bovine insulin. And another advantage of GMO insulin is that it doesn't come from another species. The human body is less likely to have side effects caused by insulin if it's not from animal sources.

The genetic modification of insulin also has allowed larger production of insulin, which helps to avoid the health risks associated with a lack of insulin in people with diabetes. Without the mass production of insulin, insulin scarcity could lead to deaths.

Finally, genetically engineered insulin is made using a sterile process. When insulin is extracted from a bovine or porcine source, the process is not always as clean, Moghe says. GMO insulin is also vegan, whereas insulin from an animal source is not.

In fact, insulin from animal sources is no longer available in the United States. Beef insulin for use by humans was stopped in 1998, and pork insulin was discontinued in 2006, according to the U.S. Food and Drug Administration (FDA).

GMO Insulin: Today and Beyond

Researchers continue to experiment with new modifications to GMO insulin in order to maximize its therapeutic potential for people with diabetes. New ultra-rapid insulins and an inhaled insulin have hit the market in recent years, and according to an article published in 2021, the future of insulin therapy could also include once-weekly insulins, oral insulins, and glucose-responsive “smart” insulins that only act when blood sugar levels are high.

Though GMOs are a concern for many consumers, genetically modified insulin has proven to be a safe, effective, and superior product for managing diabetes.