Wegovy vs. Mounjaro

There’s been no shortage of news coverage exploring the potential of new injectable medications aimed at treating overweight and obesity, in addition to their original purpose, treating diabetes.

Wegovy and Mounjaro are two of the most popular names in this space, alongside Ozempic and Zepbound. But these are all brand names for a pair of medications known as semaglutide and tirzepatide. Both act by tricking your body into producing extra insulin and slowing down digestion, but there are subtle differences that might make one better than the other.1

In this guide, our experts will review those differences to help you understand how they compare in advance of a consultation with a medical professional. And toward that end, whichever medication ends up best for you, we can share a recommendation for the consultation and convenient prescription process: Henry Meds.

At Innerbody Research, we thoroughly investigate and test the products and services we review. For this comparison between Wegovy and Mounjaro, we researched more than 50 scholarly articles on GLP-1 medications, obesity, and diabetes. We also identified several key players in telehealth that currently offer online prescriptions for these medications or for compounded generic versions that you can get for less if you don’t have insurance.

Our comparison was further bolstered by an in-depth review and contributions from Dr. Matt Segar, a member of Innerbody’s Medical Advisory Board who is also a published researcher in the GLP-1 RA field. His expertise proved invaluable. This is a rapidly evolving field, both on the research side and for customers and patients. We’ll continue to monitor its developments and update this content to reflect any important changes.

Over the past two decades, Innerbody Research has helped tens of millions of readers make more informed decisions involving staying healthy and living healthier lifestyles.

Wegovy and Mounjaro are brand-name versions in a class of drugs that were originally intended to treat type 2 diabetes but are increasingly popular as weight loss medications. These drugs are called glucagon-like peptide-1 receptor agonists (GLP-1 RAs), but the brands use different active ingredients:

• Wegovy’s active ingredient is semaglutide, the same as Ozempic.
• Mounjaro’s active ingredient is tirzepatide, the same as Zepbound.

There are other brands that use these same ingredients, as well, which can add to the confusion around them.

Tirzepatide, semaglutide, and liraglutide brand names

Here’s a quick cheat sheet to show you which brand names go with which GLP-1 RAs:

Many people seek a comparison of Wegovy and Mounjaro to better understand their weight loss options, but the clearest way to do this is to consider the actual medications rather than the brands; your prescribing doctor would likely not debate between Wegovy and Mounjaro because those brands are prescribed for two different purposes (weight loss and diabetes, respectively), even though the active medications (semaglutide and tirzepatide) are each prescribed for both weight loss and diabetes.

Despite the fact that brands like Mounjaro and Zepbound both use tirzepatide and that Wegovy and Ozempic both use semaglutide, each brand is typically prescribed for one purpose or the other.

• Wegovy is the brand of semaglutide for weight loss, whereas Ozempic is the diabetes version of the same active ingredient.
• Zepbound is the brand of tirzepatide prescribed for weight loss, while Mounjaro is its diabetes version.

For that reason, in this guide, we’ll often speak about semaglutide and tirzepatide, as opposed to using brand names, and our primary focus is weight loss. But keep in mind that many studies looking into these drugs have been conducted in diabetic patients, with weight loss reported as an additional specific result.

Branded semaglutide and tirzepatide are most commonly injections delivered subcutaneously with an autoinjector pen, not unlike an EpiPen. Fortunately, the regimen only includes one injection per week, so you don’t have to stick yourself daily like you would with liraglutide. Available compounded versions of their base ingredients can be injected, but they may also be available as oral medications.

In addition to being a GLP-1 RA, Mounjaro is also a glucose-dependent insulinotropic polypeptide receptor agonist (GIP RA), and we’ll dive a little deeper into how that improves its efficacy below.4

While these medications are extremely similar, there are four areas in which their differences are palpable enough to become points of comparison based on research studies. Those include their respective efficacy, safety, cost, and convenience. Again, differences in these categories are slight, but they could tip the scales in your decision making or in your conversation with a doctor. A prescribing medical professional would need to determine whether you’re a suitable candidate for GLP-1 medications and, if so, which of these would be better for you.

Keep in mind that there are versions of semaglutide and tirzepatide that are approved for either weight loss (Wegovy, Zepbound) or diabetes (Ozempic, Mounjaro), but not one version that's approved for both, even though effects should be the same between them.

Let’s take a closer look at each criterion.

Effectiveness

Advantage: Tirzepatide

While both drugs can produce weight loss and antidiabetic effects, head-to-head studies conducted among diabetic participants reveal that tirzepatide is more effective at both.2 Research comparing the two in non-diabetic populations isn’t yet available.

Both semaglutide (the active ingredient in Wegovy) and tirzepatide (the active ingredient in Mounjaro) effectively cause the body to produce more glucagon-like peptide 1 (GLP-1), which then causes your body to create more insulin. Both medications also cause your rate of digestion to slow, allowing you to feel fuller for longer as food makes its way through your system.1

But in addition to being a GLP-1 receptor agonist, tirzepatide has a second, more pronounced mechanism of action regarding glucose-dependent insulinotropic polypeptide (GIP).4 We’ll get into the weeds on how each peptide is responsible for the drugs’ weight loss and antidiabetic effects a little later on, but a simple, convincing bit of comparison comes from a pair of studies conducted in the past few years.

In one study published in Diabetes, Obesity, and Metabolism, tirzepatide produced a 17.8% weight loss effect in diabetic patients. That same study saw semaglutide produce a 12.4% weight loss. Both are significant numbers, but tirzepatide clearly performed better.3

Another study saw a significant difference in blood sugar levels between semaglutide and tirzepatide groups, and a similar study saw improved pancreatic islet function and insulin production from its tirzepatide group compared to semaglutide.2 5

Both medications are effective for weight loss and blood sugar control, but tirzepatide appears to be the slightly more effective choice.

Safety

Advantage: Semaglutide

The risk of serious side effects from GLP-1 receptor agonists is relatively low, but common side effects like nausea, indigestion, and other forms of GI upset can be expected by most users.6 These digestive issues tend to fade as your body adjusts to the medication and you make lifestyle adjustments based on how the medication affects your metabolism. Semaglutide seems to have a slight edge in reducing the risk of side effects, based on studies that assessed the risk of GI upset and pancreatitis.2 10

In our conversations with diabetic GLP-1 RA users, we’ve found that doctors will often start patients out on Ozempic, which uses the same active ingredient as Wegovy (semaglutide), as opposed to a drug based on tirzepatide. However, these decisions may also be influenced by availability, as GLP-1 RAs are currently in short supply. Ultimately, your consultation with a doctor or other medical professional will determine which GLP-1 RA is the best place for you to start.

Cost

Advantage: Tirzepatide (depending on your insurance)

Cost analyses for these drugs can be extremely difficult, especially when insurance gets involved. The typical price range charged to insurers for either is around $900-$1,300 per month, and one insurance plan will bring that cost down more or less than another, even within the same company. A comparison across insurance companies is made all the more difficult by differences in their tiered classification structures.

For instance, Anthem uses a three-tier system and designates brand-name Mounjaro and Wegovy as tier 2 drugs. Meanwhile, United Healthcare uses a four-tier system and classifies Mounjaro as a tier 3 drug; Wegovy isn’t even in its formulary. So, how much you pay through insurance will have a lot to do with how your plan interacts with different drug tiers and what that means within your deductible.

Without insurance, the list prices for each are as follows:

• Mounjaro: $1,069.08/month
• Wegovy: $1,349.02/month

That may not be an enormous disparity, and each company has different savings programs for certain groups, which may further reduce costs.

However, when looking at costs by weight lost, Mounjaro has a slim advantage. One research paper examined how the costs of tirzepatide (the active ingredient in Mounjaro) would compare to semaglutide (the active ingredient in Wegovy) to lose the same amount of body weight. Researchers found that a 1% reduction in body weight would cost $985 using tirzepatide versus $1,845 using semaglutide — nearly double the cost.3

However, this might all go out the window as pharmaceutical companies decide to price their drugs differently, and we’ve seen providers of compounded GLP-1 RAs regularly charging more for tirzepatide than semaglutide. For example, tirzepatide from Henry Meds costs $449/month compared to $297/month for semaglutide.

Ultimately, cost is a muddy picture, but research points toward Mounjaro as the less expensive treatment option.

Convenience and availability

Advantage: Semaglutide

Wegovy (semaglutide) and Mounjaro (tirzepatide) are both pretty convenient. They both only require weekly injections and come in autoinjector pens that make the process relatively easy, even for people squeamish around needles.

An ongoing autoinjector shortage might make it difficult to come by either of these branded medications.11 That may lead you to seek out compounded versions, but these often come in vials and require you to inject yourself with a traditional syringe. This is where semaglutide becomes more appealing.

In our research, we’ve consistently found more companies offering semaglutide than tirzepatide. And when companies offer both, there are typically more ways to take the semaglutide that don’t require needles, such as oral tablets or sublingual drops.

So, while branded Mounjaro and Wegovy may be roughly equal in terms of convenience, Wegovy’s base ingredient — semaglutide — is more readily available and easier to take.

GLP-1 receptor agonists mimic the activity of glucagon-like peptide (GLP) 1 throughout the body, which contains numerous GLP receptors. These drugs’ effects derive from receptor agonism in the central nervous system, digestive tract, and pancreas.

Here’s a quick look at how they work in each of those areas:

In addition to these primary mechanisms of action, studies have also shown that GLP-1 RAs can increase insulin sensitivity by reducing inflammation.25

When all of these actions combine, you end up with a decreased appetite between meals, a desire to eat less during meals, and a more balanced insulin response to the food that you eat. This reduced caloric intake can lead to weight loss, as can the inhibition of new fat cell creation resulting from tamed blood sugar.

The short answer is that tirzepatide (the active ingredient in Mounjaro and Zepbound) appears to be slightly more effective than semaglutide (the active ingredient in Wegovy and Ozempic) in studies — both for weight loss and diabetes. The reason for this is two-fold, but it helps to understand a little bit about glucose metabolism for it all to make sense.

Essentially, as your body breaks down food, a portion of it becomes glucose that enters your bloodstream. When your body senses an increase in blood sugar, the pancreas creates insulin, a hormone that causes glucose to leave the blood, depositing it in other tissues for energy use later.17

The pancreas also creates glucagon as a check against insulin’s activity. Glucagon initiates gluconeogenesis, the process by which the body creates glucose to increase blood sugar. These two hormones work together to keep your blood glucose levels balanced. A pancreatic dysfunction is at the root of Type 2 diabetes.18

So, how does this all relate to tirzepatide's increased efficacy? Well, one theory is that not all GLP-1 RAs are created equal. For example, results were surprisingly different when early clinical studies pitted liraglutide (the active ingredient in Saxenda) against semaglutide.

In the eighth trial of the STEP program (for the Semaglutide Treatment Effect in People with obesity), researchers compared semaglutide directly to liraglutide in comparable doses.19 After 68 weeks, participants on liraglutide lost an average of 6.4% body weight, but those on semaglutide saw nearly triple that effect, losing an average of 15.8% of body weight.

Studies comparing semaglutide to tirzepatide have yielded similar results, but this time in tirzepatide’s favor. One saw tirzepatide knock off an average of 17.8% body weight compared to 12.4% from semaglutide after 72 weeks.3

But GLP-1 receptor agonism likely isn’t superior in tirzepatide, as it appears to have an imbalanced effect favoring its agonism of glucose-dependent insulinotropic polypeptide (GIP) receptors. While GLP-1 RAs increase insulin production by stimulating beta cells in the pancreas, GIP RAs inhibit glucagon production in the pancreas.4

As we said above, glucagon acts as a check against insulin. If semaglutide only increases insulin production in the pancreas, that increase could dangerously lower blood sugar without an attendant increase in glucagon production.4 But if tirzepatide works harder to inhibit glucagon production than it does to increase insulin production, it can have the same positive effects on blood sugar as semaglutide without needing to produce as much insulin. This would reduce the amount of glucose the body stores in its efforts to reduce blood sugar, a phenomenon central to lipogenesis (the development of fat cells).20

At this point, we know that these drugs’ mechanisms of action differ slightly, but the full picture of why tirzepatide provides superior results in studies remains theoretical. Research continues, but results thus far indicate its greater efficacy for weight loss and blood sugar control.

Perhaps because of its single mechanism of action compared to tirzepatide’s dual mechanisms, semaglutide performs slightly better from a safety perspective in clinical trials. For example, one of the studies referenced above breaks down how each drug performed in terms of nausea, diarrhea, and vomiting:2

As you can see, these aren’t night-and-day differences, but if you already have a sensitive stomach, it might be smarter to start with semaglutide to give yourself the best chance of mitigating digestive symptoms. A medical professional will help you determine which medication would be better for you, so be sure to share any history of digestive upset or conditions as they help you determine your best starting point.

Among more serious potential adverse effects, GLP-1 receptor agonists have been linked with an increased risk of thyroid cancer and gastroparesis in people who’ve used the drugs for 1-3 years.7 More research is needed to determine if one version of the drug or another is safer in this regard. There also appears to be an increased risk of gallbladder diseases, and tirzepatide may put you more at risk of pancreatitis than semaglutide.8 9 10

As with their effectiveness, GLP-1 RAs are considered to be generally safe for most potential users. But side effect intensity seems to vary a bit from one brand to the next, and there are potentially mild and some severe adverse effects to consider.

Most common side effects from these medications occur primarily along the digestive tract and include:

• Nausea
• Bloating
• Vomiting
• Diarrhea
• Indigestion
• Belching
• Flatulence

Much of the digestive discomfort people experience comes from slowed gastric emptying, which is another way of saying that you’ll digest food more slowly. If you eat portions that are too big or don’t wait long enough between meals, you’re likely to feel some bloating or nausea.

Low blood sugar is also somewhat common as the body adjusts to changes in insulin and glucagon activity.

On the rarer but more serious front, GLP-1 RAs have been associated with increased risks of thyroid cancer and pancreatitis.7 9 Though uncommon, it's critical that you divulge any thyroid issues, pancreatic concerns, or family history of cancer to your doctor. Many physicians will want to see recent lab test results for things like thyroid hormones or HbA1c before they’ll write you a prescription. Once they have all the pertinent data, they’ll be able to guide you toward one brand of GLP-1 RA or another.

Does semaglutide or tirzepatide cause muscle loss?

There is reasonable concern that the loss of body weight from GLP-1 RAs comes from a reduction in lean mass (muscle) as much as it does from body fat. Research to this point is somewhat inconclusive. Several papers point to a preservation or increase in lean body mass.21 One even showed improvements in muscle composition (a decrease in muscle fat) in non-diabetic participants.27 Others have seen a reduction of lean body mass, making up around 20-50% of total weight lost, but it’s important to note that this was a review of research into several anti-diabetic drugs including some that aren’t GLP-1 RAs.26

Research into low-calorie diets reveals that exercise and a high protein intake can help preserve muscle mass and even build muscle while restricting calories, so you can’t just eat junk, not exercise, and still expect these drugs to work miracles.22 Your overall health can improve by adding exercise and a healthy, protein-rich diet to a GLP-1 RA routine.

Not everyone can just walk into their doctor's office and demand a prescription for Wegovy, Mounjaro, or any other GLP-1 RA. There are specific diagnostic criteria you have to meet to be eligible. These criteria become especially important as GLP-1 medications receive rave news coverage that makes average people want to try them, even if they don't need them.

At this time, the FDA has approved some GLP-1 RA brands for weight loss and others for diabetes treatment. Here’s a quick breakdown:

As you can see, even Ozempic — probably the most recognizable name in the space, thanks to its association with celebrity weight loss — is actually approved for diabetes treatment. When you go through a provider that issues prescriptions and provides GLP-1 medications through a compounding pharmacy, you’re getting the same base ingredient that’s approved for both diabetes and weight loss under different brand names.

Essentially, to qualify for a GLP-1 RA prescription intended for weight loss, you must have a BMI of 30 or above. (For reference, a person at 5'10" would need to weigh 210lb to qualify.) You could also qualify if you have a BMI of at least 27 alongside certain comorbidities, such as diabetes or hypertension. However, that criterion appears to be somewhat flexible from one physician to the next, with things like depression being taken into account as a comorbidity of overweight and obesity.

Wegovy (semaglutide) and Mounjaro (tirzepatide) are both delivered via subcutaneous injection — you inject them under the skin, typically into adipose tissue (body fat). You don’t inject them straight into your veins.

To make the process of at-home injections as accessible as possible, the companies that make these drugs deliver them in autoinjector pens. You simply press these against your injection site (typically the upper arm, lower abdomen, or mid-thigh) and either depress a button or push hard enough that the needle pops out and pierces the skin.

Some GLP-1 RAs are packaged with multiple doses per pen, but Wegovy and Mounjaro each contain only one dose per pen, injected weekly. Some other GLP-1 RAs, like liraglutide, call for daily injections.

Patients will titrate up from a base dose of a GLP-1 RA to an eventual maintenance dose, increasing the dosage after around four weeks at each stop, depending on any adverse effects that may arise.

GLP-1 RAs are not cheap, and insurance coverage varies from plan to plan. Let’s look at Wegovy and Mounjaro as examples of cost. Based on the information from the companies’ websites, Mounjaro has a lower list price than Wegovy. Each drug is injected once weekly, and each package comes with four doses — a one-month supply.

Both companies offer savings programs for insured individuals intended to lower the medication cost, but there are caps on these programs. Sometimes, they can bring your cost down to $0, but that depends on the nature of coverage and your plan's pharmacy deductible.

Here’s what they cost:

As you can see, Mounjaro has a lower initial cost but an inferior savings plan for those whose insurance covers it. That said, the difference in savings is only $73, while the difference in monthly price is nearly $300.

Mounjaro has a favorable savings plan for those who have insurance but whose plans don’t cover it. However, under either of Mounjaro’s savings programs, if your out-of-pocket cost is less than the maximum coverage, you still have to pay $25, whereas Wegovy users may pay nothing if their coverage is good enough.

Individuals without any insurance, or with government insurance, are typically ineligible for either company's savings plan.

Typically, generic forms of patented medications don’t hit the market until those patents expire, which can take up to 20 years in many cases. Wegovy and Mounjaro are relatively new, but you can still access unbranded forms of their active ingredients through compounding pharmacies thanks to a current shortage. These aren’t technically “generic” medications; they’re compounded drugs.

Compounding pharmacies exist to create custom formulas for individual patients. Imagine that you needed a life-saving drug, but you were allergic to one of the additives a pharmaceutical company used in creating the tablets. A compounding pharmacy could legally make you a custom version of that drug without that allergen.

These pharmacies can also step in and fill gaps in the supply chain when there are shortages of certain drugs. In the case of GLP-1 RAs like Wegovy and Mounjaro, there’s technically an autoinjector shortage, but it’s impacting the availability of GLP-1 RAs nonetheless. With no end to the shortage in sight, numerous companies saw the opportunity to use compounding pharmacies to provide active GLP-1 RA ingredients to patients directly.

Opting for compounded semaglutide or tirzepatide, rather than brand-name equivalents, can dramatically reduce the cost of the medication, making it an ideal path for anyone without insurance who wants to utilize these medications. In our experience, they can also be somewhat less strict about applying the complete diagnostic criteria to receive a prescription, making the drugs more widely available.

But the autoinjector shortage applies here, as well. That means you may have to inject yourself with a traditional syringe. However, some compounding pharmacies also make it possible to administer these drugs in novel ways, like sublingual drops or dissolving tablets, removing the need for needles altogether.

While the most obvious route to accessing Wegovy or Mounjaro would be to go through your primary care physician or the prescribing medical professional who helps you manage diabetes, overweight, or obesity, there are numerous online platforms that provide more convenient access. Through these platforms, you can get prescriptions for either brand name GLP-1 RAs or their compounded active ingredients, and the ones that offer brand names can often help you navigate your insurance and company savings plans to try to get you the lowest possible monthly price.

Here’s a quick look at costs for some of the top players offering GLP-1 RAs:

As you can see, the issue with some online providers, especially those that offer brand-name GLP-1 RAs, is that they often charge monthly fees to access an ongoing prescription, as well as occasional fees for telehealth doctor's appointments. These fees can range from around $20 to $300, which is typically a lot more expensive than what you'd pay to go to a doctor in person.

Many compounded medication providers lack those monthly fees, but you can’t use your insurance to pay for the medication. You can try submitting for reimbursement, but you may not get anything back.

We recommend Henry Meds for its low cost and varied medication formats among these providers. You can get tirzepatide as an injectable or as oral tablets, and you can get semaglutide as an injectable, liquid oral drops, or fast-dissolving sublingual tablets.

For brand-name medications, Sesame has the lowest monthly membership cost with insurance coverage — and the price is even lower for Costco members.

Should I take brand-name GLP-1 RAs or compounded versions?

Choosing to go with compounded or brand-name GLP-1 RAs can be a confusing decision, so we put together this quick reference to give you some guidance:

Essentially, insured people with GLP-1 RA coverage are the only ones who would benefit from using either an in-person doctor or a telehealth company providing prescriptions for brand-name drugs. Nearly everyone else would be financially better off by going with compounded alternatives. This is especially true if you’re squeamish about needles, as several companies offer compounded GLP-1 RAs as tablets, liquid oral drops, or lozenges.

Understanding your options beyond just Wegovy and Mounjaro can also help you decide where to start. There are two ways to view alternatives:

1. Examining alternative GLP-1 RAs that aren’t brand-name Wegovy or Mounjaro
2. Examining alternative treatments for weight loss outside of GLP-1 RAs

Let’s take a look at each approach.