Saxenda vs Mounjaro (aka Zepbound) for weight loss: which one is better?

Trying to figure out the differences between Saxenda vs Mounjaro vs Zepbound? You’re not alone. Many people feel overwhelmed by all the weight loss medications out there. Learning about the options can help you talk with your healthcare provider about which medically supervised weight loss approach is right for you.

Two options gaining attention for their weight loss effectiveness are liraglutide and tirzepatide. If you haven’t heard of them, you may recognize their brand names. Liraglutide is sold under the brands Victoza for type 2 diabetes and Saxenda for weight loss. Similarly, tirzepatide is sold as the brands Mounjaro for type 2 diabetes and Zepbound for weight loss.

Keep reading this article for an in-depth look at Saxenda vs Mounjaro (aka Zepbound), including their costs, effectiveness for weight loss, dosage, side effects, how they work, and more. 

Saxenda vs Mounjaro — aka Zepbound

Saxenda, Mounjaro, and Zepbound are brand-name prescription medications that are similar in some ways. For example, all 3 come as prefilled pens you use to give yourself weight loss injections. But these medications have differences too, including their indications, which are the specific uses the U.S. Food and Drug Administration (FDA) has approved each one to treat.

The FDA approved Saxenda (liraglutide) and Zepbound (tirzepatide) for long-term weight management alongside a reduced-calorie diet and increased exercise in adults with obesity or overweight who meet one of the following criteria:

• An initial body mass index (BMI) of 30 or greater
• An initial BMI of 27 or greater and at least one weight-related health condition, such as high blood pressure, heart disease, or high cholesterol

Saxenda is also FDA-approved for use in children ages 12 years and older, if they meet one of the following criteria:

• An initial body weight of at least 132 pounds
• An initial BMI that converts to an adult BMI of 30 

Unlike Saxenda, tirzepatide is not FDA-approved for children.

Zepbound and Mounjaro share the identical active ingredient of tirzepatide, but Mounjaro isn’t FDA-approved for weight loss. Instead, the FDA approves Mounjaro to lower blood sugar (glucose) in adults with type 2 diabetes, along with diet and exercise. Mounjaro is commonly used off-label for weight loss, which led to the drugmaker Eli Lilly coming out with Zepbound. Zepbound is FDA-approved for weight management in adults who meet the criteria noted above.

Saxenda vs Mounjaro vs Zepbound for weight loss

Substantial weight loss can occur while taking any one of these weight loss medications. Between Saxenda and Zepbound, most clinical trial results suggest that tirzepatide (Zepbound) leads to more weight loss than Saxenda (liraglutide), on average. While individual results vary, looking at the clinical trials details helps give you an idea of what to expect.

The primary clinical study for Saxenda compared the medication to a placebo (an injection that contained no active ingredient). Trial participants were overweight or obese adults who didn’t have type 2 diabetes and who followed a reduced-calorie diet and increased physical activity. After 56 weeks, the majority of participants who took a maximum daily dose of 3.0 milligrams of Saxenda lost 5 to 10% of their initial body weight. And more than a third of Saxenda participants experienced weight loss greater than 10% of their body weight. On average, Saxenda resulted in weight loss of about 8% of initial body weight.

Based on the average loss of 8% of body weight, someone with a starting body weight of 250 pounds can reasonably expect to experience a 20-pound weight loss with Saxenda.

A clinical trial of Zepbound also compared the medication to a placebo. Participants also followed a lower-calorie diet and began exercising more. After 72 weeks, over 85% of participants who took Zepbound lost 5% or more of their body weight. More than half of participants taking at least 10 milligrams of Zepbound weekly experienced a body weight reduction of 20% or more. On average, those taking the highest dose (15 milligrams weekly) of Zepbound lost 20.9% of their initial body weight.

Based on this average, a person with a starting body weight of 250 pounds can reasonably expect to experience a 52-pound weight loss with Zepbound.

Since Mounjaro and Zepbound use the same active ingredient, Mounjaro leads to weight loss and helps with blood sugar control. And losing weight may help improve long-term outcomes in people with type 2 diabetes. In a Mounjaro clinical trial, individuals with diabetes received treatment with either Mounjaro or semaglutide (Ozempic). Participants also followed diet and exercise plans. After 40 weeks, more than 65% of people taking Mounjaro lost at least 5% of their initial body weight. Participants who took tirzepatide 15 milligrams weekly had nearly double the weight loss of participants who took semaglutide 1 milligram weekly. 

If you’re not sure if Mounjaro or Zepbound is better for you, ask your healthcare provider if weight loss drugs are right for you.

Saxenda (liraglutide) vs Mounjaro/Zepbound (tirzepatide) at a glance

* Prices according to manufacturer websites as of March 2024.

Saxenda (aka Victoza) vs Mounjaro for people with type 2 diabetes

Mounjaro and Zepbound contain the same active ingredient tirzepatide, but Mounjaro is FDA-approved for type 2 diabetes and Zepbound for weight loss.

Similarly, Saxenda’s counterpart, Victoza, contains the same active ingredient (liraglutide) but has different uses. The FDA approves Victoza, along with diet and exercise, for people with type 2 diabetes who meet certain criteria.

Weight loss is not an FDA-approved indication for Victoza. However, Victoza may promote weight loss in people with type 2 diabetes as an additional benefit.

In a separate Mounjaro clinical trial and Victoza clinical trial, researchers studied how well each medication lowered blood sugar levels compared to other diabetes medications. In these studies, both Victoza and Mounjaro were found to be highly effective for lowering blood sugar levels. But Mounjaro led to a greater improvement in a shorter amount of time. 

The table below highlights a few key differences of Victoza vs Mounjaro for type 2 diabetes.

How Saxenda and Mounjaro or Zepbound work

Saxenda and Moujaro work in similar ways. This section looks at how these medications work for promoting weight loss and managing blood sugar levels.

What’s in Saxenda and Mounjaro and Zepbound

Saxenda contains the active ingredient liraglutide. Liraglutide belongs to a class of medications known as glucagon-like peptide-1 receptor agonists (GLP-1s). Like other receptor agonist medications in this class, Saxenda works by mimicking GLP-1 to help replace or enhance its effects.

Mounjaro and Zepbound contain the same active ingredient, tirzepatide. Tirzepatide mimics 2 peptides in the body: GLP-1 and glucose-dependent insulinotropic peptide (GIP).

When these peptides activate certain receptors in the body, changes occur in your digestive and metabolic processes that promote weight loss and better glucose regulation.

How liraglutide and tirzepatide work for weight loss

Both liraglutide and tirzepatide work for weight loss by altering the normal digestive process, increasing the sensation of feeling full and slowing the passing of food through the gut. While using liraglutide or tirzepatide, a person’s appetite decreases, which helps promote weight loss.

How liraglutide and tirzepatide work to lower blood sugar for people with type 2 diabetes

Liraglutide and tirzepatide work to lower blood sugar by mimicking GLP-1 (liraglutide) and GLP-1/GIP peptides (tirzepatide). In the body, these peptides communicate with the pancreas, the organ that makes insulin. When blood sugar rises, GLP-1 and GIP tell the pancreas to release insulin into the blood; this, in turn, helps lower blood sugar. The GLP-1 and GLP-1/GIP receptor agonist medications act exactly like these peptides, ultimately leading to lower blood sugar levels.

Can you switch from Saxenda to Zepbound or Victoza to Mounjaro

Yes. As long as a licensed medical professional confirms that the switch is safe and appropriate for you. Also, when switching from one medication to another, a dosing adjustment may be needed to limit side effects caused by switching to a stronger GLP-1 or GLP-1/GIP receptor agonist.

Can you take 2 at the same time?

No. The FDA warns against using more than one GLP-1 or GLP-1/GIP receptor agonist medication at the same time. Combining medications may increase the risk of serious side effects.

What to know before you take Saxenda, Mounjaro, or Zepbound

Before starting any medication, it’s essential to weigh the risks and benefits. This section highlights some of the side effects and risks to consider before you take Saxenda, Mounjaro, or Zepbound. 

Saxenda and Mounjaro or Zepbound side effects

Saxenda, Mounjaro, and Zepbound may cause similar side effects. Typically, side effects are mild and go away within a few weeks as the body adjusts to the medication. Side effects may also be more noticeable after you increase your dose.

Since tirzepatide is stronger than liraglutide, side effects are more likely to occur and may be more bothersome with tirzepatide compared to liraglutide. But, as with all medications, individual experience varies.

Common side effects of liraglutide and tirzepatide include:

• Nausea
• Diarrhea or constipation
• Upset stomach
• Abdominal pain

Rare but serious side effects of these medications may include allergic reactions, pancreatitis, low blood sugar if taken with insulin or certain diabetes medications, or kidney problems. For a full list of possible side effects, see the prescribing information for Saxenda, Mounjaro, and Zepbound.

Who shouldn’t take Saxenda or Mounjaro and Zepbound

The FDA requires boxed warnings (aka black box warnings) on the label information (aka prescribing information) for all GLP-1 and GLP-1/GIP receptor agonist medications. This is because thyroid tumors were observed in mice and rats when researchers were testing these medications in animal studies. It isn’t known if this risk applies to humans, but as a precaution, the FDA recommends against using these medications in anyone with a personal or family history of medullary thyroid carcinoma (a type of thyroid cancer) or multiple endocrine neoplasia syndrome type 2 (MEN2). 

People with a known hypersensitivity to tirzepatide or liraglutide or who are pregnant or want to get pregnant should also avoid the medications. 

What each medication costs

The retail cost for a 4-week supply (as of the time of this writing) for Zepbound vs Saxenda vs Mounjaro according to drugs.com are:

• Saxenda: $1,349
• Mounjaro: $1,069
• Zepbound: $1,113

These prices represent the out-of-pocket price of the products without insurance. You may pay less if your insurance plan covers Saxenda, Mounjaro, or Zepbound. Also, the manufacturers of Saxenda, Mounjaro, and Zepbound offer savings cards that may help you get discounted medication. 

Mounjaro vs Saxenda vs Zepbound, which should you choose?

Saxenda, Mounjaro, and Zepbound all work to help people lose weight when used alongside a lower-calorie diet and increased exercise. 

For individuals with type 2 diabetes, Mounjaro is proven to lower blood sugar and promote weight loss. And even moderate weight loss can improve long-term health for people with type 2 diabetes.

If you’re interested in weight loss but you don’t have type 2 diabetes, Saxenda or Zepbound may be a better fit. Of the 2, Zepbound is the stronger medication based on a comparison of clinical trial results. But individual results can vary, and some people may not be able to tolerate the higher doses necessary to see optimal weight loss results.

Choosing a weight-loss medication is a decision that’s made between you and a healthcare provider after discussing your medical history, other medications, and other unique factors. They will help determine if one of these medications is safe and appropriate and aligns with your health needs and goals.

Find a weight loss provider on Klarity and see if Zepbound is right for you

While Saxenda and Zepbound can be effective weight loss tools, it’s important to remember they’re only one part of a comprehensive plan for reaching and maintaining a healthy weight. A well-rounded approach involves other aspects, such as diet changes, boosting physical activity, addressing related mental health concerns, and building a strong community for support. Find a weight loss provider on Klarity and start your weight loss journey today. 

The information provided in this article is for educational purposes only and should not be construed as medical advice. Always seek the guidance of a qualified healthcare professional with any questions or concerns you have regarding your health.

How we reviewed this article: This article goes through rigorous fact-checking by a team of medical reviewers. Reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the author.