Be honest: Do you tend to tune out whenever a medication commercial gets to the list of side effects? It’s natural — side effects are kind of boring and easy to dismiss — but knowing the “what ifs” is important. It helps you make informed decisions about your health, manage potential risks, and recognize when something might be wrong.
And that holds true with Saxenda, the brand name for liraglutide that’s FDA-approved for chronic weight management. While the medication is considered safe, it’s still smart to know what to look out for and how to help reduce their severity. Here’s everything you need to know about Saxenda side effects.
What is Saxenda?
Saxenda, a brand name for liraglutide, is a once-daily injectable medication that is FDA-approved for chronic weight management. It falls under the class of glucagon-like peptide-1 (GLP-1) receptor agonists, a group of medications that function like a naturally occurring hormone in the body to regulate satiety and appetite, explains Dr. Lydia Alexander, M.D., President of the Obesity Medicine Association. GLP-1 drugs mimic that hormone by stimulating the pancreas to produce insulin and slowing gastric emptying. When combined with diet and exercise, Saxenda can be an effective tool for long-term weight management. Clinical trials showed that the average person loses 5% of their body weight in eight weeks, 7% in 16 weeks, and 8% in 24 weeks.
Common side effects of Saxenda
As with any prescription weight-loss medication, taking Saxenda comes with potential side effects, which is why it's important to weigh the overall benefits and risks for your health. In clinical studies, around two-thirds of patients taking Saxenda reported gastrointestinal issues (compared to 39% of patients taking placebo), with nausea being the most common (find a full list of side effects on Saxenda’s site). Here are the most common side effects and how frequently they occur:
- Nausea (Occurs in about 39.3% of patients, compared to 13.8% placebo)
- Diarrhea (Occurs in about 20.9% of patients, compared to 9.9% placebo)
- Constipation (Occurs in 19.4% of patients, compared to 8.5% placebo)
- Vomiting (Occurs in about 15.7%, of patients, compared to 3.9% placebo)
- Injection site reaction (Occurs in about 13.9% of patients, compared to 10.5% placebo)
To help mitigate some of these common Saxenda side effects, Alexander recommends staying hydrated, eating slowly, and reducing how many foods you eat that are high in fat. “High-fat foods take longer to digest,” she explains, which can worsen constipation and nausea when your digestion is already slowed down by your medication.
Mild side effects of Saxenda
Saxenda’s side effects are typically mild. Along with the common ones mentioned above, you may also experience the following:
- Abdominal pain
- Bloating
- Dizziness
- Fatigue
- Gastroenteritis (inflammation of the stomach lining and intestines)
- Indigestion
Serious side effects of Saxenda
Though rare, there are some more serious side effects that could occur when taking Saxenda. Go over these with your provider and find out if you’re at a higher risk for any of them.
- Pancreatitis (inflammation of the pancreas)
- Low blood sugar levels (hypoglycemia)
- Increased heart rate
- Increased risk of thyroid cancer
- Gallbladder problems
Explanation of Saxenda side effects
Those more serious side effects can sound pretty scary. Here’s a breakdown of some of them, including the real risks they pose and how to know if they’re happening to you.
Thyroid cancer risk
During clinical studies on rodents, liraglutide (the active ingredient in Saxenda) caused thyroid C-cell tumors, mainly including medullary thyroid cancer (MTC). However, there is not enough evidence to suggest that this risk applies to humans, and it remains unclear whether Saxenda (liraglutide) can cause thyroid cancer in people. As a result, Saxenda carries a black box warning — an FDA-mandated safety alert — based on potential risks rather than a confirmed link.
Generally speaking, MTC is an “exceedingly rare” form of thyroid cancer, says Alexander, adding that she’s personally never seen it before in her practice. That said, if you have a family history for MTC or have had it yourself, your doctor will likely not advise you to take Saxenda.
Tips for managing or identifying thyroid cancer
Thyroid cancer can present with a range of symptoms. Common symptoms include:
- A lump on the side or front of the neck, sometimes growing quickly
- Swelling in the neck
- Pain in the front of the neck, sometimes radiating to the ears
- Hoarseness or persistent voice changes
- Difficulty swallowing
- Trouble breathing
- A constant cough not related to a cold
While not all of these indicate cancer, if you notice any of them, it’s important to consult your doctor for further evaluation.
Pancreatitis
This condition occurs when the pancreas — an organ that produces digestive enzymes and regulates blood sugar — becomes inflamed. It can develop suddenly (acute) or persist over time (chronic). While commonly linked to heavy alcohol use or gallstones, pancreatitis has also been reported with Saxenda. The manufacturer advises you to stop using Saxenda and contact your doctor immediately if you experience severe, persistent abdominal pain, with or without vomiting, that may radiate to your back. “If there’s a history of pancreatitis, then these medications should not be used or used with extreme caution,” says Alexander.
Tips for managing pancreatitis
Managing pancreatitis depends on its severity, so always consult your doctor. Treatment for mild cases usually involve IV fluids, pain relief, and a clear liquid or low-fat diet. Severe cases may require hospitalization, fasting, a feeding tube, or even surgery if complications arise. Since severe alcohol abuse is a common trigger, avoiding it is essential for recovery.
Gallbladder problems
Another potential side effect of Saxenda is gallbladder disease, which includes inflammation, infection, stones, or blockages in the gallbladder. The gallbladder, a small organ beneath the liver, stores bile that helps digest fats. When you eat, the gallbladder releases bile into the small intestine to aid in digestion. “In general, with this class of medication, it’s really the loss in weight — and in many cases, the rapid loss in weight — that can predispose you to inflammation of the gallbladder,” says Alexander. That’s because when the body burns fat quickly, the liver releases extra cholesterol into the bile, which can contribute to the formation of gallstones.
Even still, the chances of this happening are rare. “In nearly 20 years of doing this, I have yet to have a single one of my weight loss patients develop gallstones as a result of their weight loss,” says Dr. Carl Knopke, M.D., a board-certified obesity medicine specialist in Riverside, California.
Tips for managing gallstones
Treatment for gallstones depends on the severity of your symptoms and overall health. Contact your healthcare provider if you experience upper abdominal pain, fever, jaundice (yellowing of the skin or eyes), or clay-colored stools. In mild cases, management may involve monitoring symptoms and dietary changes, but more severe cases may require gallbladder removal (cholecystectomy).
Low blood sugar levels
Saxenda can increase the risk of low blood sugar (hypoglycemia), particularly in adults with type 2 diabetes who are also taking insulin or sulfonylureas — two common diabetes medications that lower blood sugar levels. If you're on these medications and start taking Saxenda, your doctor may need to adjust your dosage to reduce the risk of hypoglycemia. Additionally, children 12 and older without type 2 diabetes may also experience hypoglycemia while taking Saxenda. Be mindful of symptoms like dizziness, shakiness, sweating, confusion, or fast heartbeat, and talk to your healthcare provider about how to monitor and manage your blood sugar levels.
Tips for managing blood sugar levels
Your eating habits have a lot to do with your risk for hypoglycemia, explains Knopke. For example, if you eat a meal high in sugar and low in fiber, then don’t eat for hours, you’re going to have a hypoglycemic response. Since GLP-1s curb appetite, it’s important to focus on nutrient-dense foods when you do eat. Prioritize protein and fiber-rich foods to help maintain steady blood sugar levels.
The bottom line
Saxenda generally has a low-risk profile, with common side effects including nausea, constipation, and vomiting. Although rare, there are more serious side effects, such as thyroid cancer (though this has only been shown in rodents during clinical trials), gallbladder issues, pancreatitis, and low blood sugar. Be sure to talk to your doctor about any chronic conditions or medications you're currently taking to ensure Saxenda is a good fit. If you experience any side effects, reach out to your primary care provider to address them early. Focusing on a balanced diet, ensuring you're getting the right nutrition, and staying physically active can help manage side effects like constipation and support overall well-being during treatment.
FAQs
The most common side effect of Saxenda is nausea. Eating a healthy, balanced diet rich in protein and fiber and low in high-fat and ultra-processed foods, staying hydrated, and exercising regularly can help reduce nausea. It’s also important to work closely with your doctor to adjust the Saxenda dosage if needed.
No, Saxenda is not considered a high-risk medication. A high-risk medication typically carries a significant chance of severe side effects or complications that outweigh its benefits for many users. While Saxenda has potential side effects, most are manageable and not severe for the majority of patients.
There is no official “Saxenda diet” or list of foods to avoid, but it’s true that some foods can make side effects like nausea or digestive discomfort worse. Since GLP-1 medications slow gastric emptying, which keeps food in your stomach longer, eating high-fat foods, acidic foods, or sugar-sweetened beverages may increase the likelihood of these side effects.
This content is for informational purposes only and does not constitute medical advice, diagnosis or treatment. It should not be regarded as a substitute for guidance from your healthcare provider.