GLP-1 Agonists for Diabetes: Can They Also Be Used for Weight Loss?

In recent months, glucagon-like peptide-1 (GLP-1) receptor agonist drugs have been in the news, as people who don’t have diabetes use them to help shed pounds. But what are GLP-1 agonists, and are they safe for weight loss?

You have probably heard about Ozempic, a prescription GLP-1 agonist used to manage blood sugar. Inspired by celebrities and social media, people who don’t have diabetes have been using this medication to help them lose weight. You might have even been affected by the shortage, as many people with Type 2 diabetes were unable to get prescriptions filled when pharmacies ran out of the medication.

Although Ozempic has become more readily available for those who need it for blood sugar regulation, the shortage has led to debate over whether GLP-1 agonists are safe for weight loss. 

What Are GLP-1 Agonists?

GLP-1 is a hormone that your body produces naturally. It has many functions, including stimulating insulin secretion and regulating hunger and food intake. GLP-1 agonists are drugs that mimic this hormone, improving blood sugar levels by promoting insulin production in the body. When blood sugar levels are high, GLP-1 helps the pancreas release the right amount of insulin. 

There are a number of different GLP-1 agonists available—including semaglutide, liraglutide, dulaglutide, albiglutide and exenatide—under many different brand names. In addition to helping people with Type 2 diabetes manage their blood sugar, GLP-1 agonists may have many other benefits, including:

  • Decreased production of glucose in the liver
  • Improved cardiovascular function, including better coronary blood flow and cardiac output and reduced risk of heart disease and cardiovascular events
  • Increased satiety (the feeling of being full after eating)
  • Lower blood pressure and cholesterol
  • Reduced risk of stroke
  • Weight loss

Recently a new diabetes medication, Mounjaro (tirzepatide), has been approved to treat Type 2 diabetes. It is similar to GLP-1 agonists; however, it also contains another incretin hormone, GIP or glucose-dependent insulinotropic polypeptide. Mounjaro activates both GLP-1 and GIP receptors to help control blood sugars similarly to GLP-1 therapy alone. Though research studies have shown Mounjaro to produce even more weight loss than Ozempic, the FDA has yet to approve this medication solely for weight loss at this time.

Because Type 2 diabetes can lead to serious complications over time, your doctor might also prescribe GLP-1 agonists to reduce your risk of related diseases and conditions. These drugs may decrease the likelihood of diabetes-related heart attack, stroke, kidney failure, nerve damage, vision problems and gum disease.

However, it’s important to keep in mind that GLP-1 agonists can cause side effects, including:

  • Abdominal pain
  • Diarrhea
  • Heartburn
  • Nausea and vomiting

More serious side effects can also occur. If you experience any of the following, seek medical treatment right away:

  • Allergic reactions, such as a rash, swelling of eyes, face, mouth, tongue or throat, or trouble swallowing or breathing
  • Dizziness or fainting
  • Persistent pain that starts in the upper left or middle of the stomach and spreads to the back and doesn’t go away
  • Rapid heartbeat
  • Swelling of legs, ankles or feet 
  • Trouble or decreased ability to urinate
  • Vision disturbances

Additionally, GLP-1 agonists may cause thyroid tumors or a type of thyroid cancer called medullary thyroid carcinoma. In studies, laboratory animals developed tumors, but it is not known if GLP-1 causes tumors in people. 

Which GLP-1 Agonists Are Approved for Weight Loss?

Semaglutide and liraglutide have been approved by the Food and Drug Administration (FDA) for weight loss. However, different formulations of these drugs exist, and not all are authorized for weight loss. In fact, there are only two FDA-approved GLP-1 agonists for weight loss: Wegovy (semaglutide) and Saxenda (liraglutide). 

Both drugs are formulated specifically for adults and children 12 and over who are obese or overweight and also have medical problems related to their weight. However, the pediatric indications for each drug are distinct. Wegovy may be prescribed for children 12 and older who meet or exceed a certain percentile BMI, whereas Saxenda may be prescribed for pediatric patients ages 12–17 who exceed a fixed weight.

Taken as injections, both have proven to be effective in helping people lose weight, causing decreased appetite and prolonged feelings of fullness. Doctors recommend using them in conjunction with increased physical activity and a healthy diet. 

However, both drugs can also cause side effects, including:

  • Abdominal pain
  • Constipation
  • Diarrhea
  • Dizziness
  • Fatigue
  • Gas and belching
  • Headache
  • Heartburn
  • Nausea and vomiting
  • Sore throat
  • Runny nose

More serious side effects can include:

  • Allergic reactions
  • Depression or suicidal thoughts
  • Gallstones and other gallbladder problems
  • Increased heart rate
  • Kidney problems
  • Pancreatitis (inflammation of the pancreas)

People who have Type 2 diabetes, especially those who take medicines like sulfonylureas or insulin, also have an increased risk of hypoglycemia, or low blood sugar, as well as vision changes.

Another prominent issue is weight gain when these medications are stopped. 

Talk With Your Doctor 

If you have been diagnosed with Type 2 diabetes or if you are overweight or obese, your doctor will discuss your options with you and help you determine if GLP-1 agonists are a good option for you.

Tell your doctor if:

  • You or anyone in your family has had medullary thyroid carcinoma or a condition called multiple endocrine neoplasia syndrome Type 2, which causes tumors to develop in more than one gland in the body.
  • You have had pancreatitis, diabetic retinopathy, gallbladder disease or kidney disease.
  • You are pregnant, breastfeeding or plan to become pregnant.
  • You have Type 1 diabetes (GLP-1 agonists cannot be used with Type 1 diabetes).

You should also make sure your doctor knows all prescription medications you are taking, as well as any over-the-counter products such as vitamins, nutritional supplements and nonprescription medications. GLP-1 agonists may change the way your body absorbs these supplements and medications.

Once you begin taking a GLP-1 agonist, you should not stop taking it without consulting your doctor. This type of medication is designed to be taken over a long-term period and should not be stopped immediately after your blood sugar normalizes, you lose weight or you feel better. You may experience weight regain when you stop taking the medication.

In addition, talk to your doctor about whether your insurance company will cover the GLP-1 you are prescribed. These medications can also be quite expensive, especially for Medicare patients without commercial insurance.

More to Read

Have questions about treating diabetes?

The experts at the University of Maryland Medical System are here to help.

Medically reviewed by Andrew Lebson, CRNP and Deep Mahapatra, DO.

Updated June 2023

Posted by Eric Jackson