Liraglutide: side effects and how to manage them

Liraglutide (Saxenda) side effects most commonly include nausea, but it usually goes away over time. Liraglutide belongs to a class of prescription drugs called glucagon-like peptide-1 (GLP-1) receptor agonists. Ozempic and Wegovy also belong to this drug class. Liraglutide is the active ingredient in two brand-name drugs: Victoza and Saxenda. 

While these medications differ in what condition they’re FDA-approved for, they cause similar side effects because they have the same active ingredient. Victoza is approved to help control blood sugar levels in people with type 2 diabetes mellitus and reduce the risk of serious cardiovascular problems, such as heart attacks. In contrast, Saxenda is approved for weight loss in those with obesity or weight-related health problems, along with diet and exercise. 

Read on to learn about the common side effects of liraglutide and get tips on how to manage them, along with details about the potential, rare, and long-term side effects of Victoza and Saxenda. 

Nausea and vomiting are the most common side effects of liraglutide. In clinical trials of Saxenda, 39.3% of participants taking 3mg of the drug daily reported nausea, while 15.7% reported vomiting.  

The risk or severity of nausea and vomiting can be higher when you first start treatment and after your healthcare provider increases your dose. To help lessen these side effects, your healthcare provider will prescribe a low starting dose of liraglutide. They’ll gradually increase your dose over time, depending on how well it works and how you tolerate it. 

In clinical trials of Victoza, investigators compared the side effects of the 1.2-milligram (mg) dose to the 1.8-mg dose and found:

• 18% of participants receiving the lower dose reported nausea, while 20% of those taking the higher dose reported nausea. For comparison, 5% of people taking a placebo also had nausea. 

• 6% of participants taking the higher dose experienced vomiting, while 9% of those taking the higher dose experienced this side effect. For comparison, 2% of people taking a placebo also had vomiting. 

The good news is that nausea, vomiting, and other types of stomach upset with liraglutide are usually temporary. Based on the drug’s clinical trials, nausea and vomiting are more likely to occur during the early phase of treatment and decrease as time goes on. As your body gets used to the drug, nausea and vomiting should lessen or even disappear within 2 to 3 months of treatment.

There are ways to help manage nausea and vomiting from liraglutide. Consider trying the following tips:

• Food choice. Avoid high-fat or spicy foods, especially during the initial phase of treatment. Also, consider limiting your intake of alcohol and carbonated beverages.

• Small meals. Try to decrease the portion size of meals. This can help because GLP-1 receptor agonists work by increasing the feeling of fullness and decreasing appetite. As such, large meals or overeating may lead to nausea.

• Mindful eating. Remember that you may feel full faster than usual, pay attention to your body’s cues. Stop eating when you feel satisfied, and don’t force yourself to eat more if you don't feel hungry.

• Hydrate. Drinking plenty of fluids is important, as nausea and vomiting may cause dehydration. 

However, if symptoms of nausea or vomiting are severe or these tips aren’t helping, you should seek medical advice from a healthcare provider. Don’t stop taking liraglutide or change your dose without talking to a healthcare provider first. 

Diarrhea is another gastrointestinal (GI) side effect of liraglutide. However, it is less common than nausea. During the Saxenda trial (3 mg daily), 20.9% of people taking the drug experienced diarrhea while the same was true for 9.9% of people taking a placebo. In the clinical trial for Victoza, 10-12% of participants reported diarrhea while taking liraglutide, while only 4% of those taking a placebo reported this side effect. 

As with nausea and vomiting, diarrhea is more likely or worse with higher doses of liraglutide. This is another reason why healthcare providers prescribe a low dose to start, then slowly increase it over time.  

You can usually manage mild diarrhea at home without medical attention. Sticking to bland foods, such as the BRAT diet, can be helpful. Again, it is important to remain hydrated, as diarrhea causes fluid loss, possibly leading to dehydration. When trying to combat diarrhea, taking a short-term, over-the-counter remedy like Pepto-Bismol can help.

19.4% of Saxenda recipients and 5% of Victoza recipients reported constipation in each drug's respective clinical trials. None of the reports were considered severe, and no participants had to stop the trial due to constipation.

While usually mild, constipation may still be a bothersome side effect of liraglutide. To help manage constipation or regulate bowel movements, consider the following approaches:

• Increase your intake of fiber and water

• Exercise to increase bowel activity

• Try a stool softener, such as docusate, to make stool easier to pass

A pharmacist or healthcare provider can assist you in selecting a gentle laxative if other approaches aren’t helping.

Injection site reactions are skin responses to the subcutaneous (under-the-skin) injections required to administer liraglutide. Symptoms may include a skin rash, reddening, pain, or itching at or near the injection site. Injection sites for liraglutide include your thigh, abdomen, or upper arm. In clinical trials of Saxenda and Victoza, injection site reactions were reported in 2-14% of participants.

Following a few essential tips can help prevent or minimize injection site reactions. First, you should avoid choosing the same spot for every dose. Instead, it’s better to rotate the injection site to prevent irritation and allow the skin to heal between doses. Since liraglutide is a once-daily injection, it is important that you change your injection site within the area you choose with each injection. 

Also, injecting cold solution may cause or worsen injection site reactions. Both Victoza and Saxenda must be refrigerated prior to the first use. Taking the medication out of the refrigerator ahead of time will allow it to reach room temperature and make for a more comfortable injection. You can leave liraglutide at room temperature for up to 30 days, being careful to store it away from direct sunlight.

Less commonly, liraglutide may cause other digestive side effects besides nausea, vomiting, and diarrhea (see above). In trials, less than 10% of participants taking Saxenda experienced dyspepsia (indigestion), abdominal pain, GERD (acid reflux), or flatulence. In Victoza’s clinical trials, about 9.5% of those taking Victoza reported decreased appetite, while 5.5% reported indigestion. 

Digestive side effects of liraglutide typically ease over time. It also helps to use lifestyle changes to manage GI discomforts. For example, to help limit indigestion and reflux, try eating smaller meals and avoiding spicy or acidic foods. If these strategies aren’t enough, your healthcare provider may recommend short-term treatment with medication to reduce stomach acid. Popular choices include proton-pump inhibitors (PPIs) like omeprazole and H2-blockers like famotidine. 

Note that Victoza and Saxenda also cause another stomach effect known as gastroparesis, which refers to the slowed movement of stomach contents into the intestinal tract. It isn’t known if Victoza and Saxenda are safe for people with existing gastroparesis.

Hypoglycemia (low blood sugar) occurs when the level of glucose in the blood drops below 70 mg/dL. Warning signs of hypoglycemia include sweating, dizziness, irritation, shakiness, fast heart rate, confusion, headache, and blurred vision. Severe hypoglycemia may be life-threatening, so it’s crucial to seek emergency medical attention if these symptoms occur.

In clinical trials of liraglutide, people who were taking other diabetes medications for type 2 diabetes had an increased risk of hypoglycemia, especially when liraglutide was combined with other diabetes drugs In a clinical trial of patients with type 2 diabetes, hypoglycemia occurred in about 28% of those taking Saxenda when they were also taking sulfonylurea, an oral medication to treat diabetes.

Monitoring blood sugar carefully and paying attention to warning signs of hypoglycemia can help you catch this side effect before it becomes serious. This is especially important if you take liraglutide in addition to certain diabetes medications, such as insulin or a sulfonylurea drug like glipizide. Before starting liraglutide, your healthcare provider will go over your current medications to help avoid unsafe interactions.

Liraglutide may cause headaches. In studies of Saxenda and Victoza, injection site reactions were reported in 10.5-13.6% of clinical trial participants who received liraglutide.

Mild headaches can be treated at home with an OTC pain reliever, such as ibuprofen or acetaminophen.

Rarely, headaches related to liraglutide may be related to hypoglycemia or low blood sugar. If headaches occur with other symptoms mentioned in the hypoglycemia section above, contact a healthcare provider right away.

Rarely, liraglutide may cause pancreatitis (inflammation of the pancreas). Pancreatitis wasn’t seen during studies of the drug but was reported after the drug came on the market. 

While taking Victoza or Saxenda, tell your doctor about any persistent, severe pain in your abdomen that may spread to your back that may occur with vomiting. In the case of these symptoms, seek emergency medical attention. If you have pancreatitis, your healthcare provider will have you stop using liraglutide. 

Gallbladder disease, like cholecystitis (inflammation of the gallbladder) and cholelithiasis (gallstones) is a less common but serious side effect of liraglutide. In clinical trials, 3.1% of people taking Victoza and 2.2% of people taking Saxenda experienced gallbladder disease. In most cases, people needed surgery to remove the gallbladder.

Losing a large amount of weight very quickly can raise the risk of gallbladder disease. You can help protect your gallbladder health by closely following the plan made with a healthcare provider, including aspects of diet and exercise. You should not increase the dose of liraglutide too soon or take it in combination with other weight-loss drugs or products to help ensure that weight loss occurs at a healthy pace.

In animal studies, liraglutide was shown to cause thyroid C-cell tumors, including medullary thyroid carcinomas (MTC), in rats and mice. Because of this, liraglutide carries a black box warning from the FDA to alert healthcare providers and patients about the possible risk of thyroid cancer. But, it is unclear whether liraglutide causes thyroid cancer in humans. 

Healthcare providers generally advise against using Victoza or Saxenda (or other GLP-1 receptor agonists) in people with a family or personal history of MTC, as well as those with multiple endocrine neoplasia syndrome type 2 (MEN 2), a condition known to increase the risk of thyroid cancers.

During treatment with liraglutide, tell your healthcare provider if you notice symptoms of thyroid cancer, which may include:

• Bumps, bulges, or masses in the neck

• Voice hoarseness

• Shortness of breath

• Trouble swallowing 

Like most medications, liraglutide (Victoza and Saxenda) carries potential risks and benefits. This medication controls high blood sugar levels, decreases appetite, and creates the feeling of being “full” faster and longer. Keep in mind that not everyone experiences side effects, and many people may only notice mild or temporary side effects with liraglutide. 

Note that this article does not discuss all possible side effects of liraglutide. Other side effects, such as allergic reactions, are possible. Talk to a healthcare professional to determine if liraglutide is right for you.

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Current version

June 15, 2023

Written by

Patricia Weiser, PharmD

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.