Using Mounjaro and Wegovy can lead to weight loss, but only Wegovy is currently FDA-approved for chronic weight management. Mounjaro is currently approved to help manage blood sugar levels in people with type 2 diabetes (T2DM), but clinical trials have shown significant weight loss as well. So which is the better weight loss drug? This article can help you understand how these meds work and you can talk to your doctor to see if either is right for you.
What is Wegovy?
Wegovy (semaglutide) is a glucagon-like peptide-1 receptor agonist manufactured by Novo Nordisk. It is a weekly injection given under the skin in your stomach, thigh, or upper arm. The U.S. Food and Drug Administration (FDA) approved Wegovy as an obesity medication when used along with diet and exercise. Adults must have a body mass index (BMI) of 30 kg/m^2 or higher to use this medication or have a BMI of 27 kg/m^2 or higher with at least 1 weight-related health condition such as high blood pressure, T2DM, or high cholesterol. Wegovy can also be used in pediatric patients 12 years of age and older who are considered obese.
The active ingredient, semaglutide, works by stimulating your pancreas to produce insulin while also preventing the release of glucagon. This helps regulate your blood sugar levels. It is also thought to affect the parts of your brain that manage appetite and slow how fast you digest food. This leads to you feeling fuller for longer (satiety), eating less, and losing weight. Wegovy should not be used along with other diabetes medications that contain semaglutide such as Ozempic or Rybelsus. It should also be avoided with other GLP-1 receptor agonists, including Bydureon BCise (exenatide), Victoza (liraglutide), Trulicity (dulaglutide), and the weight loss medication Saxenda (liraglutide).
Wegovy and Mounjaro are not approved if you have a personal or family history of medullary thyroid carcinoma (a type of thyroid cancer) or multiple endocrine neoplasia syndrome type 2, which causes tumors in the thyroid and parathyroid glands. Be sure your healthcare provider is aware of the medical conditions you have such as pancreatitis, kidney disease, T2DM, diabetic retinopathy, depression, or if you are pregnant, plan to become pregnant, or are breastfeeding.
What are some common side effects of Wegovy?
The most common side effects of Wegovy include:
- Nausea
- Vomiting
- Constipation
- Diarrhea
- Stomach pain
- Headache
- Fatigue
- Indigestion
- Gas
Wegovy can sometimes cause serious side effects, including:
- Serious, life-threatening allergic reactions (hives, swelling of the tongue or throat, and difficulty breathing)
- Pancreatitis
- Gallbladder problems such as gallstones
- Increased risk of thyroid tumors
- Low blood sugar
- Diabetic retinopathy complications
- Kidney injury and failure
- Increased risk of depression and suicidal thoughts
- Cardiovascular problems such as an increased heart rate
What is Mounjaro?
Mounjaro (tirzepatide) is a brand-name diabetes drug manufactured by Eli Lilly. It is FDA-approved to treat adults with type 2 diabetes when used along with lifestyle changes such as a reduced-calorie diet and regular exercise. It is not for use in people with type 1 diabetes or pancreatitis, or to treat pediatric patients under 18 years of age.
It is a weekly injection given under the skin in your stomach, thigh, or upper arm, just like Wegovy.
Tirzepatide mimics 2 types of incretin hormones naturally produced by your body. It is classified as a glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist. These 2 hormones together lower your fasting and postprandial (after a meal) blood sugar levels, decrease food intake and reduce body weight.
While it is not currently approved for weight loss, Mounjaro was granted a fast-track designation for this indication in October 2022 by the FDA. It is expected the FDA will approve the New Drug Application for Mounjaro for chronic weight management sometime in 2023.
Like Wegovy, Mounjaro should also be avoided if you are taking other GLP-1 receptor agonists or if you have a personal or family history of medullary thyroid carcinoma (a type of thyroid cancer) or multiple endocrine neoplasia syndrome type 2.
What are some common side effects of Mounjaro?
The most common side effects of Mounjaro are gastrointestinal, which is similar to Wegovy. They can include:
- Nausea
- Diarrhea
- Decreased appetite
- Vomiting
- Upset stomach
- Constipation
- Stomach pain
Mounjaro can also rarely cause serious side effects similar to Wegovy, including:
- Serious, life-threatening allergic reactions (hives, swelling of the tongue or throat, and difficulty breathing)
- Pancreatitis
- Gallbladder problems such as gallstones
- Increased risk of thyroid cancer
- Low blood sugar
- Diabetic retinopathy complications
- Kidney damage
Does Mounjaro or Wegovy work better for weight loss?
There have not been any clinical studies that directly compare the average weight loss of people taking Mounjaro and Wegovy.
However, in a phase 3 trial with Mounjaro, significant weight loss was seen when compared to a placebo. People taking 5mg of Mounjaro a week lost an average of 15% of their body weight after 72 weeks. Higher doses of Mounjaro saw even more weight loss. People taking 10mg a week lost an average of 19.5% and those taking 15mg a week lost 20.9% of their body weight. This was compared to those who lost 3.1% of their body weight taking a placebo for the same period of time.
For Wegovy, they conducted a 68-week double-blind trial of once-weekly subcutaneous semaglutide (at a 2.4 mg dose) or placebo. The average weight reduction after 68 weeks was 14.9% from their starting weight with Wegovy versus 2.4% with placebo. This equaled an average of 33.7 pounds (15.3 kg) lost as compared to 5.7 pounds (2.6 kg) lost in the placebo group.
The participants in both of these trials also made lifestyle changes. They ate a healthy, low-calorie diet and regularly exercised.
Is Wegovy or Mounjaro cheaper?
This can depend on several factors, including your insurance coverage. Many insurance companies do not cover weight loss medications. And because Mounjaro is still only approved as a diabetes medication, it may not be covered when used off-label for weight loss. On average, the cost of Mounjaro is typically less than Wegovy, but that can change based on the indication and availability. You can check out the cost savings at Universal Drugstore for Mounjaro, Wegovy, as well as thousands of other prescription and OTC medications.
Sources
https://www.novo-pi.com/wegovy.pdf
https://reference.medscape.com/drug/ozempic-rybelsus-wegovy-semaglutide-1000174#4
https://reference.medscape.com/drug/mounjaro-tirzepatide-4000264
