What are the GLP-1 drugs?
Updated on April 9, 2024. Previously published on November 28, 2022 by Sendra Yang, PharmD, MBA. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
Table of contents
- Types of GLP-1 Drugs
- Benefits of GLP-1 Drugs
- How Do GLP-1 Drugs Work?
- Adverse Effects of GLP-1 Drugs
- Key Takeaways For GLP-1 Drugs
- Want To Know More About GLP-1 Drugs?
GLP-1 drugs, also known as GLP-1 agonists, GLP-1 receptor agonists, incretin mimetics, or GLP-1 analogs, are commonly used to treat type 2 diabetes. [1, 2]
In recent years, however, healthcare providers have also been prescribing GLP-1 medication to support weight loss. Such is the case with popular drugs like Ozempic® and Wegovy®, which are both formulations of semaglutide, a GLP-1 receptor agonist developed by Novo Nordisk. [3]
All that said, what are the different GLP-1 drug types, what is GLP-1 medication for weight loss, and how exactly do these GLP-1 receptor agonist drugs work? We explore the details below.
Types of GLP-1 Drugs
Various types of GLP-1 drugs are available, each with unique forms of administration. Here's a breakdown of the currently available GLP-1 medication options and examples:
Short-Acting Injectable GLP-1 Drugs
GLP-1 agonist drugs that are dosed once or twice a day are considered short-acting formulations. These GLP-1 RA medications are typically administered via subcutaneous injection, meaning they’re injected into the fatty tissue just beneath the skin using a small needle. This method allows for the GLP-1 drug to be absorbed into the bloodstream gradually, providing sustained effects over the course of the day. [1, 2]
Examples of GLP-1 drugs with once- or twice-daily dosing schedules include [1, 2]:
- Exenatide (twice a day)
- Liraglutide (daily)
- Lixisenatide (daily)
Long-acting injectable GLP-1 drugs
Long-acting subcutaneous injections of GLP-1 drugs are administered just once a week. This delivery method offers a convenient and less frequent dosing schedule compared to shorter-acting formulations, which typically require daily administration. [1, 2]
Examples of GLP-1 long-acting medicines are [1, 2]:
- Dulaglutide (once a week)
- Exenatide extended-release (once a week)
- Semaglutide (once a week)
Oral GLP-1 Drug
Most GLP-1 drugs are administered via injections, typically as subcutaneous injections. However, semaglutide stands out as an available oral option, offering a convenient and weekly alternative for individuals who may have difficulty with injections. [2]
This oral administration route allows semaglutide to be absorbed through the gastrointestinal tract and enter the bloodstream, where it exerts its effects. [2]
Benefits of GLP-1 Drugs
It’s estimated that about 1 in 10 Americans have diabetes, with up to 95% having type 2 diabetes. [4] This condition is most common in older adults; however, young children, teens, and young adults may also develop insulin resistance, a state in which the body can become resistant to the effects of a hormone called insulin. [4, 5] The key roles of insulin are to break food down into blood sugar and help cells store and use the sugar for energy. [5]
When the cells become resistant to insulin, sugar can remain in the bloodstream, raising blood sugar levels. This may eventually lead to [4]:
- Heart disease
- Vision loss
- Kidney disease
Fortunately, GLP-1 drugs are an effective medication used to treat type 2 diabetes. [2] Research shows that GLP-1 medication can help lower blood sugar levels by increasing insulin and reducing the secretion of a hormone that raises blood sugar levels. [6]
GLP-1 drugs can also help facilitate weight loss by curbing hunger and increasing feelings of fullness. Depending on the type of GLP-1 drug, patients can lose varying weight. For example, research finds that individuals who incorporate healthy lifestyle choices and take semaglutide can lose an average of 33.7 pounds. Alternatively, those who take liraglutide—another type of GLP-1 agonist—can lose about 10.5 to 15.8 pounds. [3]
How Do GLP-1 Drugs Work?
We all have a naturally occurring hormone in our bodies called glucagon-like peptide-1 (GLP-1), which is produced in the gut. Food intake, primarily the consumption of carbohydrates (sugars), stimulates the GLP-1 hormone. Once it’s called into action, it binds to specific GLP receptors in various tissues, including the pancreas. [1, 2]
When the hormone binds to receptors within the pancreas, it produces insulin. Insulin, in turn, helps the body’s cells take up the sugar in the blood to ultimately lower the blood sugar level, assisting those with type 2 diabetes. [1, 2]
All that said, GLP-1 drugs work by mimicking the GLP-1 hormone in your body. When you take a GLP-1 medicine, it works in three main ways [1, 2, 7]:
- Stimulates the release of insulin by the pancreas after eating.
- Inhibits the release of another hormone called glucagon. (Glucagon stimulates the liver to release sugars that have been stored in the bloodstream.)
- Slows the absorption of glucose into the blood by reducing the speed at which the stomach empties after eating, thus making you feel more satisfied or extending the sensation of feeling full after a meal.
These effects combine to keep your blood sugars down and support the other benefits of taking a GLP-1 drug.
For instance, GLP-1 drugs induce weight loss by mimicking the GLP-1 hormone, akin to their actions in diabetes management. In this case, the drugs’ abilities to bind to GLP-1 receptors in the brain help to trigger [3]:
- Reduced appetite
- Increased feelings of fullness
- Decreased food intake
Adverse Effects of GLP-1 Drugs
Common side effects of GLP-1 drugs are nausea, vomiting, and diarrhea. [1, 2, 7] You may also experience [1, 2, 7]:
- Dizziness
- Mildly increased heart rate
- Infections
- Headaches
- Upset stomach
It’s also important to note that GLP-1 drugs increase satiety; if you continue to eat while feeling full, it may lead to a wave of temporary, mild nausea. If you do experience nausea, your healthcare provider should slowly increase your dosage.
Since the majority of GLP-1 drugs are subcutaneous injections, injection-site itchiness and redness may also occur. [1, 2]
Fortunately, this class of medications has a low risk of hypoglycemia or low blood sugar [1, 2].
If you have a family history of medullary thyroid cancer, multiple endocrine neoplasias, or acute pancreatitis, you should avoid GLP-1 drugs [1,2,4]. If you have a severe allergic reaction to GLP-1 medications or are pregnant, you should also avoid taking this class of drugs. If you have severe gastrointestinal diseases like gastroparesis and inflammatory bowel disease, you should not take GLP-1 medicines.
Key Takeaways For GLP-1 Drugs
- GLP-1 drugs are a class of medications used to treat type 2 diabetes and obesity.
- They work in three main ways: stimulate insulin production, inhibit glucagon release, and slow insulin absorption by reducing the speed of stomach emptying.
- The majority of GLP-1 drugs are injections, with only one currently available oral option.
- The most common side effects of GLP-1 drugs include nausea, vomiting, and diarrhea.
- GLP-1 drugs should be avoided if a family history of medullary thyroid cancer or other endocrine neoplasia is present. In addition, it is not recommended if you have acute pancreatitis, severe allergic reaction to GLP-1 drugs, are pregnant, or have gastroparesis and inflammatory bowel disease.
Want To Know More About GLP-1 Drugs?
If you have type 2 diabetes, have obesity, or want to learn more about the benefits and side effects of GLP-1 drugs, consider talking to your healthcare provider to see if this class of medications is an option for you.
You can check in on your health and wellness with Everlywell. Everlywell offers weight management telehealth to give you access to providers that can help with weight loss, including through a prescription of GLP-1 if applicable. Learn more about Everlywell and what is available for you and book online weight loss visit.
Related content
Zepbound® for Weight Loss: Benefits, Dosage, and More
HbA1c vs. fasting glucose: understanding the similarities and differences
What is the effect of exercise on blood sugar?
GLP-1 medications and exercise used together for type 2 diabetes: what to know
Getting insurance coverage for weight loss drugs like Wegovy®, Ozempic® and other GLP-1s
References
- Collins L, Costello RA. NCBI Bookshelf. Glucagon-like peptide-1 receptor agonists. Medical Citation URL. Accessed April 9, 2024.
- Diabetes care. American Diabetes Association. Published January 1, 2022. Medical Citation URL. Accessed April 9, 2024.
- Castro M. GLP-1 agonists: Diabetes drugs and weight loss. Mayo Clinic. Medical Citation URL. Accessed April 9, 2024.
- Type 2 diabetes. Centers for Disease Control and Prevention. Published December 16, 2021. Medical Citation URL. Accessed April 9, 2024.
- Insulin Resistance and Diabetes. CDC. Medical Citation URL. Accessed April 9, 2024.
- Nachawi N, et al. The role of GLP-1 receptor agonists in managing type 2 diabetes. Cleveland Clinic Journal of Medicine. Medical Citation URL. Accessed April 9, 2024.
- Latif W, Lambrinos KJ, Rodriguez R. NCBI Bookshelf. Compare and contrast the glucagon-like peptide-1 receptor agonists (GLP1RAs). Medical Citation URL. Accessed April 9, 2024.
Sendra Yang, PharmD, MBA received her Doctor of Pharmacy and Master of Business Administration degrees from Wingate University School of Pharmacy. She is a skilled medical information professional with nearly 10 years of experience in the pharmaceutical industry, pharmacy education (including as an Assistant Clinical Professor at the Medical College of Wisconsin), and clinical practice. She has also been a medical writer and editor for consumer health and medical content. Sendra is passionate about translating complex medical concepts into simple and easy-to-understand information.