Glucagon-like Peptide-1 (GLP-1) Agonists

Glucagon-like peptide-1 (GLP-1) receptor agonists are drugs that treat people with type 2 diabetes (T2D). They lower blood sugar by triggering the pancreas to release insulin after meals. GLP-1 receptor agonists are used with lifestyle changes like diet and exercise.^1-4

How do GLP-1 receptor agonists work?

Blood glucose levels depend on the activity of several hormones. Some of these hormones include:¹

• Insulin, which transports glucose out of the bloodstream
• Glucagon, which causes the liver to release glucose into the bloodstream
• Incretins, which triggers the release of insulin from the pancreas

GLP-1 is an incretin hormone. It is released by the intestines after you eat a meal. It then binds to a protein called the GLP-1 receptor. This causes the pancreas to release insulin, which reduces blood sugar.^2,3

People with T2D release low levels of GLP-1 after eating. This leads to high blood sugar because it impairs the activity of insulin. Taking drugs that mimic GLP-1 may lower blood sugar. These drugs are called GLP-1 receptor agonists. They work by:^1,4

• Increasing the amount of insulin released by the pancreas after meals
• Slowing the rate of food moving through your stomach (gastric emptying)
• Reducing the amount of glucagon made by the liver

GLP-1 receptor agonists can lead to weight loss. This lowers the risk of heart problems and overall mortality. GLP-1 receptor agonists are useful for people with T2D who are carrying extra weight or have heart disease.^1,5

Examples of GLP-1 receptor agonists for type 2 diabetes

Examples of GLP-1 receptor agonists include:⁴

• Bydureon^® Bcise (exenatide ER)
• Byetta^® (exenatide)
• Ozempic®, Rybelsus® (semaglutide)
• Trulicity® (dulaglutide)
• Victoza^® (iraglutide)

The choice of which one to use depends on a number of factors. Concerns include:⁴

• Whether you have other medical conditions
• Whether you have side effects
• Preference for self-injecting or oral drug form
• Personal preference
• Cost

What are the possible side effects?

Common side effects of GLP-1 receptor agonists include:^1,3

• Vomiting
• Diarrhea
• Dizziness
• Headache
• Injection site reactions
• Constipation
• Weakness

More serious side effects are possible, including:^1,3

• Pancreas inflammation (pancreatitis)
• Kidney problems
• Low blood sugar
• Gallbladder disease
• Allergic reactions
• Low blood platelet count
• Thyroid tumors

These are not all the possible side effects of GLP-1 receptor agonists. Talk to your doctor about what to expect when taking GLP-1 receptor agonists. You also should call your doctor if you have any changes that concern you when taking GLP-1 receptor agonists.

Other things to know

Take GLP-1 receptor agonists exactly as your doctor prescribes. Most versions are self-injected using a prefilled injector pen. Semaglutide also comes as an oral option.¹

You may start at a low dose to avoid side effects. Then you may slowly increase the dose. If you have side effects, you may switch to a different GLP-1 receptor agonist. Longer-acting (once-weekly) versions have a lower risk of side effects.¹

Your doctor may combine GLP-1 receptor agonists with other T2D treatments. GLP-1 receptor agonists can be combined with other treatments except dipeptidyl peptidase 4 (DPP-4) inhibitors.¹

Some GLP-1 receptor agonists should not be used if you have other medical conditions. In general, you should not use GLP-1 receptor agonists if you:^1,4

• Have a history of pancreatitis
• Have type 1 diabetes
• Have severe gastrointestinal disease
• Are allergic to medicine ingredients
• Are pregnant

Unfortunately, GLP-1 receptor agonists are the most expensive drug for T2D. They typically cost $500 to $700 for a 30-day supply. However, this is cheaper than hospital stays and treatments for diabetes complications. GLP-1 receptor agonists are still valuable treatment options.⁴

Before beginning treatment for T2D, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you take. This includes over-the-counter drugs.