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How Does Mounjaro Work For Weight Loss?

By Norma Ector · · Updated

Mounjaro and weight loss
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Mounjaro (often misspelled "Mountjaro") is the brand name for tirzepatide, a once-weekly prescription injection made by Eli Lilly. It is not a diet program or an app.

The FDA approved Mounjaro to improve blood sugar in adults with type 2 diabetes. In late 2023, it approved the same drug under the name Zepbound for chronic weight management.

In this article, we explain how tirzepatide works for weight loss, who it is for, and what to watch out for.

Explain What is Mountjaro

Mounjaro is the brand name for tirzepatide, an injectable prescription medicine. It is given once a week under the skin of the stomach, thigh, or upper arm.

Mounjaro is approved for type 2 diabetes. When tirzepatide is prescribed specifically for weight loss, it is usually as Zepbound, which contains the same active ingredient.

Overview of Mountjaro and Weight Loss

The FDA approved Zepbound for adults with a BMI of 30 or higher, or 27 or higher with at least one weight-related condition, such as high blood pressure, type 2 diabetes, or high cholesterol.

It is meant to be used along with a reduced-calorie diet and more physical activity, not as a replacement for them.

How Mountjaro Works

how does mounjaro work for weight loss

Photo by Andres Ayrton From Pexels

Tirzepatide mimics two gut hormones, GLP-1 and GIP. According to the FDA, it activates receptors of hormones secreted from the intestine to reduce appetite and food intake.

It also helps the pancreas release insulin when blood sugar is high and slows how fast the stomach empties. Together, these effects help people feel full sooner and eat less.

The dose starts low and is raised gradually, usually no more than once every 4 weeks, to limit stomach side effects. Your doctor sets the dose; do not change it on your own.

Benefits of Using Mountjaro for Weight Loss

In the main FDA trial of adults with obesity or overweight without diabetes, people on the highest dose lost about 18% more of their body weight than those on placebo over 72 weeks.

In a trial of adults with type 2 diabetes, the highest dose led to about 12% more weight loss than placebo. Tirzepatide also improves blood sugar control in people with type 2 diabetes.

Disadvantages of Using Mountjaro for Weight Loss

Tirzepatide is not right for everyone, and it has real downsides for weight loss.

  • Side effects: MedlinePlus lists nausea, vomiting, diarrhea, decreased appetite, constipation, and upset stomach as common side effects.
  • Serious risks: Possible serious problems include pancreatitis, gallbladder problems, low blood sugar (especially with insulin), kidney problems from dehydration, allergic reactions, and suicidal thoughts.
  • Boxed warning: Tirzepatide caused thyroid C-cell tumors in rats. People with a personal or family history of medullary thyroid cancer or MEN 2 should not use it.
  • Cost and access: It is expensive, and many insurance plans do not cover it for weight loss alone.
  • Weight regain: Weight may come back if the medicine is stopped, so plan with your doctor for the long term.

Should You Try Mountjaro for Weight Loss?

That is a decision for you and your doctor. Tirzepatide for weight loss requires a prescription and medical supervision.

Your doctor will consider your BMI, health conditions, other medicines, and family history before prescribing it. Avoid online sellers offering it without a prescription, and do not use it during pregnancy.

Tips for a Successful Mountjaro Weight Loss Plan

Mounjaro For Weight Loss

Photo by Andres Ayrton From Pexels

If you and your doctor decide on tirzepatide for weight loss, these habits can help.

Eat smaller meals and stop when you feel full, since overeating can worsen nausea. Prioritize protein, vegetables, and fluids.

Stay active, including strength training, to help preserve muscle as you lose weight. Keep all follow-up visits so your doctor can adjust your dose and watch for side effects.

Common Mistakes to Avoid

Don't increase your dose faster than prescribed, and don't combine tirzepatide with other GLP-1 medicines such as semaglutide.

Don't buy unapproved or compounded versions from unverified sources. Don't ignore severe stomach pain that won't go away, which can be a sign of pancreatitis; get medical help right away.

Conclusion

Mounjaro is a once-weekly prescription injection of tirzepatide, approved for type 2 diabetes. The same drug, sold as Zepbound, is approved for chronic weight management.

It works by mimicking the gut hormones GLP-1 and GIP to reduce appetite and food intake. It can lead to significant weight loss, but it has side effects and risks, so it should only be used under a doctor's care.

FAQs

Is Mounjaro effective for weight loss?

Tirzepatide, the drug in Mounjaro, led to substantial weight loss in clinical trials. In a 72-week trial of adults without diabetes, the highest dose led to about 18% more weight loss than placebo. For weight loss, the same drug is approved as Zepbound; Mounjaro is approved for type 2 diabetes.

How soon can I expect to see results with Mounjaro?

The dose is started low and increased over weeks to months, so weight loss is gradual.

The FDA trials measured results over 72 weeks. Your doctor will track your progress and side effects.

Do I need a prescription for Mounjaro?

Yes. Mounjaro and Zepbound are prescription-only and should be used under a doctor's supervision. Be wary of online sellers offering tirzepatide without a prescription.

Do I still need diet and exercise on Mounjaro?

Yes. The FDA approved Zepbound for use alongside a reduced-calorie diet and increased physical activity. The medicine works best as part of those changes.

Are there any potential drawbacks to using Mounjaro for weight loss?

Yes. Common side effects include nausea, diarrhea, vomiting, and constipation, and there are serious risks to know about before using it for weight loss.

It carries a boxed warning about thyroid C-cell tumors seen in rats, and it should not be used by people with a personal or family history of medullary thyroid cancer or MEN 2. It is also costly and may not be covered by insurance for weight loss.

Sources

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