How does Victoza work? Everything you need to know in 2025

In the past few years, glucagon-like peptide-1 agonists, or GLP-1 receptor agonists, have gained a lot of attention for their ability to treat obesity. These drugs were approved initially as type 2 diabetes medications. Five medications in this class are FDA-approved to treat diabetes by improving blood sugar levels. Two of them are also approved as obesity treatments: semaglutide (sold under the brand names Ozempic® and Wegovy®) and liraglutide, which is sold under the brand names Victoza® and Saxenda®. 

Since these drugs treat diabetes, how does Victoza work for weight loss? 

Victoza is the brand name for liraglutide, manufactured by Novo Nordisk and approved for managing blood sugar in people with type 2 diabetes. The Food and Drug Administration (FDA) approved liraglutide as an obesity treatment for adults and teens under the brand name Saxenda. However, physicians may also prescribe Victoza for weight loss off-label. 

What do GLP-1s do? 

GLP-1 medications are prescription drugs that imitate an incretin hormone that’s naturally produced in the gut. These drugs help lower blood glucose by stimulating insulin production, which stabilizes blood sugar after eating and also help with insulin resistance. 

GLP-1 medications aid weight loss in a variety of ways. First, they slow gastric emptying—how quickly food moves through your digestive system—so you feel full longer and eat less often. They also affect the receptors in your brain that regulate appetite, helping you feel full even after you’ve eaten less. Finally, these medications act on receptors in the brain that trigger the feeling of reward after eating, reducing the desire to eat more and making it easier to stop eating when you’re full. 

Why do you lose weight with Victoza? 

Victoza supports weight loss by reducing your appetite, helping you feel full longer, and tamping down the mental reward of eating. One big difference between Victoza and your body’s natural GLP-1 hormones is how long it stays active in your system. The half-life (or the time required for your body to eliminate half of the substance) of the body’s natural peptide hormones is typically only a few minutes; the half-life of liraglutide is 13 hours. This means that liraglutide continues to affect appetite and hunger long after eating. 

This extended half-life makes liraglutide an effective medication for weight loss. In 2014, under the brand name Saxenda, it became the first GLP-1 drug approved as an obesity treatment. Like all weight loss medications, combining liraglutide with lifestyle changes like diet and exercise maximizes results. When paired with lifestyle modifications in clinical trials, people on Victoza with a body mass index (BMI) of 27+ consistently lost 8.8 to 13.2 pounds of their initial body weight. (Calculate your body mass index using our free BMI calculator.) Victoza also reduces the risk of heart attacks and other adverse cardiovascular events.

How is Victoza different from Saxenda? 

Victoza and Saxenda are different brand names for the same drug, liraglutide. Victoza is approved for the management of type 2 diabetes and is a once-daily injection given subcutaneously. Victoza comes in a prefilled multi-dose injector pen. You’ll give yourself a shot in your stomach, thigh or upper arm. (Saxenda is also taken as a daily injection and comes in a prefilled multi-dose injector pen.) 

The main difference between the two drugs is the dosage. Victoza’s manufacturer recommends once-daily doses of 0.6 mg, 1.2 mg, or 1.8 mg. Your health care provider will start you at the lowest dose and adjust the amount after one week if your glucose levels aren’t under control after the starting dose. After a second week, your physician can increase the amount to the maximum dose of 1.8 mg daily.

The manufacturer’s recommended starting dose of Saxenda is also 0.6 mg daily, but a care provider may increase the dose each subsequent week to a max of 3 mg daily. At its highest dose, research shows Saxenda helps patients achieve a weight loss of at least 4% of their starting body weight. 

While the FDA hasn’t approved liraglutide for weight loss at lower doses, your provider can prescribe a higher dose of Victoza off-label to help you achieve your weight loss goals. Prescriptions are written at a medical provider’s discretion. 

What are the side effects of Victoza? 

Victoza can have several side effects (as does Saxenda), most of which occur when you first start the drug or increase the dose. Side effects typically decrease over time as your body gets used to the drug. The most common side effects of Victoza include nausea, diarrhea, vomiting, and constipation. Changing how you eat can help manage side effects.

Victoza and Saxenda can also cause serious side effects, including pancreatitis, low blood sugar (hypoglycemia), kidney injury, allergic reactions, or gallbladder disease. Talk to your health care provider if you experience side effects while taking these medications. 

Victoza and Saxenda are not used to treat type 1 diabetes. People with certain medical conditions, including a personal or family history of medullary thyroid carcinoma (MCT) or multiple endocrine neoplasia syndrome type 2 (MEN 2), should not use GLP-1s. Do not take a GLP-1 like Victoza or Saxenda if you have ever had thyroid cancer. GLP-1s can cause fetal harm. If you are pregnant, breastfeeding, or planning to become pregnant, do not take a GLP-1. Find detailed side effects and risk information on our dedicated medication page. 

Is there a cheaper alternative to Victoza? 

One advantage of Victoza is that it’s the first GLP-1 drug available in generic form. In June 2024, Teva Pharmaceuticals, Inc. announced the launch of the first authorized generic liraglutide. Generic medications are generally much more affordable than brand-name drugs, and it makes GLP-1 medications much more affordable, especially for people whose insurance doesn’t cover weight loss drugs. 

About Found

Found is among the largest medically-supported telehealth weight care platforms in the country, having served more than 250,000 members to date. To discover your MetabolicPrint™ and start your journey with Found, take our quiz.

Found is not affiliated with Novo Nordisk A/S., the owner of the registered trademarks Wegovy®, Victoza®, Saxenda®, and Ozempic®. The content provided is for informational purposes only and should not be used as a basis for diagnosing or treating any health condition. Always follow your health care provider’s instructions to ensure safe and effective management of your health conditions. Certain medications are only FDA approved to treat conditions other than weight but may be prescribed to help aid in weight loss. Prescriptions are up to a medical provider’s discretion. For key risk information by drug, visit the Found medication page.