GLP-1 agonists: diabetes medication for weight loss

If you have type 2 diabetes and weight loss goals (agreed upon by you and your healthcare provider), you may long for a diabetes medication for weight loss that treats your condition and supports your goals. GLP-1 agonists (formally known as glucagon-like peptide-1 receptor agonists) are medications that were initially developed to manage type 2 diabetes. However, research shows that when combined with healthy lifestyle changes like diet and exercise, GLP-1 drugs can be effective at helping people manage their weight, too. 

To learn more about diabetes medication for weight loss, we spoke to Ro’s resident metabolic health expert, Dr. Raoul Manalac, M.D., about how these drugs work and if they’re a good option. Continue reading to learn more about GLP-1 drugs for weight loss.

GLP-1 agonists are effective at treating type 2 diabetes, but can these medications also help you lose weight? The answer is yes. 

“GLP-1 agonists are some of the most powerful medicines for weight management that we have to offer,” says Dr. Manalac, senior director of clinical experience for metabolic health at Ro. 

In clinical trials, GLP-1 medications have been shown to help adults with a BMI higher than 30 decrease their body weight by up to 15%. While weight loss results will vary based on the type of GLP-1 drug prescribed, dosage, and other lifestyle and health factors, they have been proven to be very effective at helping people lose weight.  

This side effect is a welcome one for many. Type 2 diabetes is closely associated with overweight and obesity, which affects 86% of people with the condition. Additionally, weight loss has been shown to be an effective tool for managing diabetes. 

But what about people without diabetes? Can you use diabetes medication for weight loss if you don’t have the condition? Dr. Manalac says they can. 

The U.S. Food and Drug Administration (FDA) has approved semaglutide (brand name Wegovy, see Important Safety Information) for weight management in people with at least one weight-related condition like high blood pressure, diabetes, or high cholesterol. That means that even people without type 2 diabetes can get a prescription for the medication.

There are a couple of mechanisms that could be at play. 

“They [GLP-1 drugs] take advantage of the body’s hormonal pathways involved with sugar processing and how food travels through the body,” says Dr. Manalac. “These actions can improve blood sugar and help people feel more full after meals.” 

Researchers suggest that GLP-1 agonists slow down the process of gastric emptying, which is how quickly food moves from your stomach into the rest of your digestive system. This helps with weight loss by keeping food in the stomach for more time, so you eat less.

“These can help patients feel more full for longer or more full on less food,” says Dr. Manalac, “and help patients feel more confident about making lifestyle changes––particularly dietary changes that play an important role in weight management.”

As with any approach to weight management, lifestyle changes are key: GLP-1 agonists should be combined with diet and exercise to be effective.

There are five types of GLP-1 agonists currently in use, and all have been shown to help with weight loss, in different capacities. These include: 

Dulaglutide

Dulaglutide, brand name Trulicity, is injected once a week (on the same day each week) at any time of the day. Trulicity can be taken with or without food.

Liraglutide

Brand names Saxenda and Victoza both contain the same active ingredient (liraglutide), but only Saxenda is approved for weight loss. Both medications are injected once daily, and the injection site should be rotated to avoid lumps forming under the skin.

Exenatide

Brand names Bydureon bcise and Byetta contain the same active ingredient (exenatide). However, Bydureon bcise is an extended release drug and injected once a week at any time of day, with or without meals. Byetta is injected twice daily within the hour before morning and evening meals. 

Lixisenatide

Lixisenatide, brand name Adlyxin, is injected once daily. The injection site should rotate with each use. The medication should be injected within one hour of the first meal of each day. 

Semaglutide

Brand names Ozempic (see Important Safety Information), Wegovy and Rybelsus both contain the same active ingredient (semaglutide), however the frequency and method of administration differ between the drugs. Ozempic and Wegovy are injected once a week and should be injected in a different site each week to avoid lumps under the skin. Wegovy is a higher dose injectable that is FDA approved for weight loss. Rybelsus is the only oral GLP-1 drug as of now, and is taken once daily with 4 ounces of water. Waiting 30 minutes after taking the tablet to eat may increase absorption.

A large review of studies concluded all of these medications were more effective than a placebo for weight loss. While there were few differences between drugs in how much weight participants lost, some drugs were more effective than others.

Currently, only Saxenda (liraglutide) and Wegovy (semaglutide) are FDA-approved for weight management. 

Both are effective, though studies have found that semaglutide led to more weight loss than liraglutide. The other GLP-1s mentioned can be prescribed off-label for weight loss in people without diabetes. Your healthcare provider can help you determine which GLP-1 medication is right for you based on your lifestyle, additional medications, and health conditions.

In addition to being an effective diabetes medication for weight loss, GLP-1 drugs may have other benefits to your health, including improved outcomes for your heart, lower blood pressure, and lower cholesterol.

A meta analysis of 25 studies found that taking GLP-1 drugs may have cardiovascular benefits in patients with type 2 diabetes. Participants taking GLP-1 drugs showed a significant reduction in cardiac events (heart attacks, strokes, cardiovascular death, and more) compared to the placebo group. More trials are currently in process to learn more about the connection between GLP-1 drugs and positive cardiac outcomes.

GLP-1 drugs have also been shown to decrease blood pressure. In a meta analysis of 60 trials, participants who took GLP-1 drugs showed significant decreases in systolic blood pressure (SBP, or the amount of pressure on the arteries while the heart beats) and diastolic blood pressure (DBP, or the amount of pressure on the arteries while the heart rests), although reduction in DBP were less significant than in SBP.

Often referred to as the “bad cholesterol,” high levels of low-density lipoproteins (LDL) can lead to high cholesterol. A meta analysis of 35 trials showed that taking GLP-1 drugs may improve lipid levels and decrease LDL. 

Whether you use diabetes medication for weight loss, blood sugar management, or both, there is a risk for side effects. Common side effects include: 

• Nausea

• Vomiting

• Diarrhea 

• Feeling full

• Skin reaction at the injection site

Some of these side effects, like nausea, go away over time or can be alleviated by reducing the dosage. Although less common, people have reported other side effects including: 

• Dizziness

• Headache

• Indigestion

• Constipation

• Abdominal pain

• Mild tachycardia (heart palpitations or pounding)

These are not all of the side effects of GLP-1 agonists. If you’re taking any of these drugs and experience side effects, consult with your healthcare provider.

GLP-1 medications are not for everyone. People who are pregnant or trying to become pregnant shouldn’t be prescribed GLP-1 drugs, and a form of contraception is encouraged with the use of the medication. 

In studies on rodents, the use of certain GLP-1 medications was associated with hyperplasia of thyroid gland (also known as Graves’ disease), and tumors. Although more research is needed to understand the impact on humans, this raises concerns for the long-term impacts of taking GLP-1 drugs on the thyroid. This is the reason why the FDA has issued its most serious warning (called a boxed warning) that GLP-1s may be associated with a type of thyroid cancer called medullary thyroid carcinoma.

Acute pancreatitis has also been noted in people who take GLP-1 drugs. While the connection is not fully understood, people with a history of pancreatitis should not be prescribed GLP-1 drugs. If pancreatitis is developed while taking GLP-1 drugs, use of the medication should stop. 

If you’re hoping to support your weight loss goals, a GLP-1 drug might be for you. Your healthcare provider can help you determine which medication will be safe and effective for you. Together, you can create a tailored treatment plan that may include medication and lifestyle changes to achieve the best results possible. 

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Current version

April 19, 2023

Written by

Kristin DeJohn

Fact checked by

Felix Gussone, MD

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About the medical reviewer

Felix Gussone, MD, Ro

Felix Gussone is a physician, health journalist and a Manager, Medical Content & Education at Ro.