Mounjaro weight loss: How tirzepatide helps you lose weight

If you’re considering medication for your weight loss journey, you and your health care provider will work together to assess your unique needs and select a drug that appropriately addresses them. As you may know, several medications on the market today are either approved by the U.S. Food and Drug Administration (FDA)  for treating obesity and excess weight or prescribed off-label for weight management. 

Among them is Mounjaro® (tirzepatide), an FDA-approved brand-name medication for treating type 2 diabetes. In May 2022, the U.S. Food and Drug Administration (FDA) approved Mounjaro for treating type 2 diabetes. Health care providers have since been prescribing Mounjaro off-label for weight management.

Tirzepatide is so effective—and there’s such a recognized need for more medications to treat obesity—that the FDA put it on the fast track for approval. And in early November 2023, that approval came: tirzepatide, to be sold under the brand name Zepbound,™ became only the seventh drug approved for chronic weight management in the U.S. Both Zepbound and Mounjaro are manufactured by Eli Lilly.

But is Mounjaro the right medication for your weight loss needs? Found’s doctor-designed weight loss program leverages MetabolicPrint,™ a proprietary metabolic health assessment engine, and clinicians specialized in obesity medicine to find the right medication for you. We’ve gathered the information you’ll need to know on Mounjaro here, so let’s get into it.

What is Mounjaro?

A few important highlights you should know about Mounjaro (tirzepatide) are:

• The U.S.-based pharmaceutical company Eli Lilly manufactures Mounjaro.
• It’s a once-weekly injectable medication. 
• It is the first and only dual-targeted treatment with a glucose-dependent insulinotropic polypeptide (GIP) receptor agonist and glucagon-like peptide-1  (GLP-1) receptor agonist for adults with type 2 diabetes.

Why is this combination interesting? GLP-1 medications, such as Ozempic® or Wegovy,® manufactured by Lilly’s competitor Novo Nordisk, have gained popularity for their efficacy in helping some lose weight. However, the combination of GIP and GLP-1 receptor agonists may have additional benefits.

In an April 2022 news release, Eli Lilly explained why this dual mechanism is so important. The release explained that the GIP hormone receptor agonist complements the GLP-1 hormone receptor agonist in a novel way. According to Lilly, GIP has been shown to decrease food intake and increase energy expenditure, resulting in weight reductions, and when combined with a GLP-1 receptor agonist, may result in greater effects on markers of metabolic dysregulation such as body weight, glucose, and lipids. This means the two incretin hormone agonists work together to help weight loss by regulating blood glucose levels and appetite, aiding body fat reduction.

But what are incretin hormones? After eating, your gut naturally releases incretin hormones—the two main ones are GIP and GLP-1. These hormones help regulate the insulin the pancreas releases to keep blood sugar levels under control effectively. More than that, the GLP-1 incretin hormone helps gastric (or stomach) emptying happen more slowly, causing you to feel fuller longer.

But those with overweight or obesity can become insulin resistant—meaning their body doesn’t respond to its signaling—this can result in too much glucose in the blood. Insulin resistance can lead to type 2 diabetes, weight gain, and elevated blood sugar levels. 

In autumn 2022, Mounjaro (tirzepatide) received a “fast track designation” from the FDA for approval to treat overweight and obesity. When the FDA fast-tracks a drug, it means the regulators expedite the review of the drug because it treats a serious condition and will fill an “unmet need.” Tirzepatide’s approval for chronic weight management came just over a year later. 

Is Mounjaro effective for weight loss?

Eli Lilly released preliminary results from its SURMOUNT-1 clinical trial in April 2022. Participants with obesity or those with excess weight–a body mass index (BMI) of 27 or greater—who had at least one other comorbidity (but not type 2 diabetes) had weight reductions of up to 52 pounds during the 72-week Mounjaro weight-loss trial. 

This randomized, double-blind tirzepatide weight-loss clinical trial included 2,539 participants throughout the U.S., Argentina, Brazil, China, India, Japan, Mexico, Russia, and Taiwan, with a mean baseline body weight of 231 pounds. All those randomly placed in the Mounjaro (tirzepatide) study began with a 2.5 mg weekly dose. They then underwent a dose-escalation period that increased by 2.5 mg every four weeks until they reached a target dose of 5 mg, 10 mg, or 15 mg.

The results found that participants on tirzepatide dropped as much as 22.5% of their total body weight. Those are impressive numbers, given that people taking other FDA-approved medications for obesity typically lose 5% to 15% of their total body weight. 

The Surmount-1 trial also showed that dosage mattered when taking Mounjaro for weight loss. Study participants on a 5 mg dose of tirzepatide experienced an average weight loss of 35 pounds or 16% of their body weight. Those on a 10 mg dose lost an average of 49 pounds or 21.4% of their body weight. 

On the highest dose—15 mg—people lost an average of 52 pounds or 22.5% of their body weight. On the other hand, the placebo group lost just five pounds or 2.4% of their body weight over that same amount of time.

While the FDA approved Mounjaro (tirzepatide) to treat type 2 diabetes, health care providers specializing in obesity are particularly excited about this medication given the preliminary SURMOUNT-1 results. 

“As a board-certified obesity specialist, I believe that Mounjaro (tirzepatide) has the potential to be a game-changer in the treatment of obesity for certain patients who may not have responded to other medicines,” says Found’s Chief Medical Officer Rekha Kumar, MD, MS. “A medication with this efficacy gives hope to patients who have run out of existing medication options because the mechanism of Mounjaro (tirzepatide) is unique.”

Is taking Mounjaro for weight loss right for you?

Only some medical providers have the right training to help you choose the proper medication for your weight loss journey. If you’re considering Mounjaro, GLP-1s, or any other medications for weight loss, consult an obesity-trained specialist first. Remember that medication should always be paired with lifestyle changes for sustainable weight loss.

Aside from your unique biology and medication needs, here are a few factors to consider before picking Mounjaro.

How much does Mounjaro cost?

According to Lilly’s list price, Mounjaro costs $1,023.04 per four-week fill. The company notes the amount you pay “will largely depend on your prescription drug insurance plan.”

One option to consider is the Mounjaro Savings Card program from Eli Lilly. With this, you may pay as little as $25 for a one-month prescription if you qualify. However, you must have commercial health insurance. Learn more about the Mounjaro Savings Card and more here.

It’s worth noting that people across the country have seen a decline in coverage for GLP-1 receptor agonist medications in the last few months as insurers struggle to cover the demand for these drugs. One potential avenue for patients for whom Mounjaro is the right medication is to indicate a history of using other medications for weight loss first. This practice is called step therapy, and your provider will be able to walk you through it. 

What are Mounjaro’s side effects?

The most common side effects of Mounjaro (tirzepatide) are:

• Constipation
• Decreased appetite
• Diarrhea
• Indigestion
• Nausea
• Stomach pain
• Vomiting

Like GLP-1 receptor agonists, tirzepatide has an FDA-mandated boxed—or black box—warning for patients with a personal or family history of medullary thyroid cancer or who have multiple endocrine neoplasia syndrome type 2. They should not take tirzepatide for weight loss or any other treatment. Read more about tirzepatide here. 

How do you use Mounjaro for weight loss?

The single-dose Mounjaro pen automatically injects the medication through its hidden needle. When you press the button on the Mounjaro pen, the needle enters your skin and retracts when the injection is complete. 

You take Mounjaro once weekly on a day that’s best for you. You can inject the medication into your upper arm, thigh, or abdominal area. Once used, dispose of the pen in an FDA-cleared sharps container. If no sharps container is available, the Mounjaro site says to use a household container that is “heavy-duty plastic with a puncture-resistant lid” and “upright, stable, leak-resistant, and properly labeled to warn of hazardous waste.”

You should keep your Mounjaro refrigerated (between 36°F and 46°F) to maintain its efficacy and make sure it doesn’t freeze. (Unrefrigerated, it can last up to 21 days; just keep it below 86°F and out of the light.) 

What is the Mounjaro dose for weight loss?

As far as dosing, health care professionals recommend patients begin their Mounjaro weight loss journey at 2.5 mg to see how well their body tolerates the drug and then increase the dose from there. It’s essential to follow your health care provider's instructions. 

Here is Mounjaro’s recommended dosing schedule:

First four weeks: 2.5 mg once weekly

Second four weeks: 5 mg once weekly

Third four weeks: 7.5 mg once weekly

Fourth four weeks: 10 mg once weekly

Fifth four weeks:  12.5 mg once weekly

Sixth four weeks: 15 mg once weekly (maximum dose)

Mounjaro alternatives

There are other medications on the market today that are part of an obesity specialist’s toolkit when addressing a person’s unique biological needs. 

Mounjaro, as mentioned, is a GIP/GLP-1 receptor agonist medication. There’s also an entire class of GLP-1 drugs like Ozempic, Saxenda,® Trulicity,® Rybelsus,® Wegovy,® and Victoza.® There’s  a lot of hype in the market today about these medications and their ability to help with weight management. As you can imagine, the demand has also created issues like supply shortages, insurance coverage gaps, and, at times, questionable prescribing practices.

All GLP-1 medications have the potential for minor and more serious side effects. Common side effects include nausea, vomiting, diarrhea, and acid reflux. More serious but less common side effects include pancreatitis, gallbladder disease, and worsening diabetic eye disease. You should not use these drugs if you have a personal or family history of medullary thyroid cancer or multiple endocrine neoplasias syndrome type 2. Detailed side effects and risk information for specific GLP-1 medications can be found here.

Alternatively, there are other medications providers can prescribe for weight loss that are more cost-effective and don’t usually require step therapy. These meds also don’t involve weekly injections. And they’re often the first line of drugs used to treat overweight and obesity. 

Our verdict: Taking Mounjaro for weight loss

While not FDA-approved for weight loss yet, Mounjaro can be an effective tool for weight management when prescribed off-label as part of a broader treatment plan that includes lifestyle changes and physical activity. 

When you’re ready, a Found-affiliated obesity-trained health care provider will be able to determine if this medication is right for you. See if you’re eligible for medication and get started today by taking our quiz.

GLP-1*

GLP-1 prescriptions, filled through your local pharmacy, are now available as part of Found's weight-loss toolkit. While GLP-1s are effective for weight loss, they are not clinically appropriate for everyone. Eligibility for a GLP-1 is based on a thorough evaluation of your medical history, eating behavior, lab work, and insurance coverage. If a GLP-1 is not appropriate for you, our providers will work with you to determine an effective medication for your health profile.