What You Need to Know About GLP-1 Receptor Agonists

Key takeaways:

• GLP-1 (glucagon-like peptide-1) is a hormone that plays a crucial role in regulating blood sugar levels and appetite.
• GLP-1 receptor agonists are medications that mimic the actions of GLP-1, helping to control blood sugar and reduce weight.
• Common side effects of GLP-1 therapies include nausea, vomiting, and diarrhea, although they are generally well-tolerated.

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What is GLP-1?

GLP-1 is the short-form term for glucagon-like peptide-1 agonists, which may also be called GLP-1 receptor agonists, incretin mimetics, or GLP-1 analogs. They belong to a class of medications used to treat type 2 diabetes by managing high blood sugar levels. They are also often effective at treating obesity. 

What are GLP-1 agonists used for?

While GLP-1 agonists were initially developed for treating type 2 diabetes, they have also been found to help with weight loss in patients with overweight or obesity, with and without type 2 diabetes. Some GLP-1 medications have been approved as weight management treatments, while others may be prescribed off-label. 

How do GLP-1 receptor agonists work?

GLP-1 receptor agonists work by stimulating the body’s insulin secretion. In individuals with type 2 diabetes, the body cannot use the insulin produced naturally, which can cause blood sugar levels to rise after eating. The GLP-1 medication will then help bring blood sugar levels back down. 

Type 2 diabetes is often associated with obesity. Approximately 86% of people with type 2 diabetes also have overweight or obesity. Weight loss can be an effective tool for managing or improving diabetes. Not only do GLP-1 medications lower blood sugar levels, but they also encourage weight loss, which is often helpful for controlling and treating type 2 diabetes. 

The weight loss caused by taking GLP-1 medications may be linked to the slowed gastric emptying resulting from GLP-1 agonists. Since the medication slows down the process by which nutrients are digested and moved from the stomach through the digestive system, patients often feel more full, from less food, for a longer time. This often leads to reduced food intake and, potentially, weight loss. GLP-1 medications should be combined with intentional eating choices and physical activity for the most effective weight management results. 

What are the benefits of GLP-1 medications?

Some of the potential benefits of GLP-1 medications may include:

• stimulating insulin secretion after eating
• delayed gastric emptying (where the movement of food from the stomach to the small intestine is slowed)
• increased satiety (ie. feeling of fullness with eating)
• inhibiting the production of glucagon from the pancreatic alpha cells
• decreasing pancreatic beta-cell apoptosis and promoting their proliferation
• an average of 2.9 kilograms of weight loss as compared to placebo
• lowering systolic and diastolic blood pressure and total cholesterol
• lowering all-cause mortality
• reducing hemoglobin A1c
• other benefits in the cardiovascular system, muscles, liver, and brain

What are the potential side effects of GLP-1 agonists?

Here are some of the most commonly reported side effects of GLP-1 medications:

• nausea, vomiting, and diarrhea (which can lead to acute kidney injury due to volume contraction/dehydration)
• dizziness
• mild tachycardia (increased heart rate)
• headaches
• dyspepsia (indigestion/upset stomach, often after eating or drinking)
• injection-site pruritus and erythema (a skin reaction to injection)
• low risk of minor episodes of hypoglycemia (low blood sugar), usually when GLP-1 medications are combined with another medication that lowers blood sugar levels
• can impact how the body absorbs other oral medications due to slowing down the digestive process

GLP-1 medications should not be prescribed to patients who are pregnant. They are also not recommended for patients with a history of pancreatitis. GLP-1 medications  should be discontinued if pancreatitis occurs  while taking the medication. Patients with a personal or family history of multiple endocrine neoplasia type 2 (MEN2) or medullary thyroid cancer should not be prescribed GLP-1 medications. 

Once a patient starts taking a GLP-1 medication, they should have regular appointments with their healthcare provider in order to monitor their blood glucose levels, weight, kidney function, and any signs of pancreatitis.

How is GLP-1 taken?

Most GLP-1 medications are taken by subcutaneous injection. However, there is one type of GLP-1 medication, semaglutide, which also comes in an oral form. Since some GLP-1 agonists are fast and some are slow, the frequency with which they should be taken varies. 

Here is a list of the GLP-1 medications currently on the market, along with how often they should be taken:

• Dulaglutide: injected once weekly
• Albiglutide: injected once weekly
• Exenatide QW: injected once weekly
• Tirzepatide: injected once weekly
• Liraglutide: injected once daily
• Lixisenatide: injected once daily
• Exenatide BID: injected twice daily
• Semaglutide: injected once weekly or taken orally once daily

In general, patients will be started on a low dose, gradually increasing depending on their blood sugar levels. 

Now that you know everything there is to know about GLP-1 receptor agonists and what they do, the next step is to talk to a Felix healthcare practitioner to find out whether a GLP-1 prescription is a good choice for you.