Mounjaro, an injectible medicine for diabetes management, is the talk of the town for its weight loss benefits. But it does not come without side effects.
As the burden of obesity grows globally, the interest in weight loss drugs has also risen proportionately. While the evergreen combination of a healthy diet and regular exercise have always been recommended to those who wish to lose weight, the availability of weight loss injectables has turned out to be game-changing. One of these drugs is Mounjaro – an injectable medicine for adults with type 2 diabetes used along with diet and exercise to improve blood sugar (glucose). It has also found to be effective for weight loss, in ways similar to the anti-diabetes drug Ozempic. A new study also shows that Mounjaro for weight loss may be more effective than Ozempic. While Mounjaro may help to achieve your weight loss goal, you should know everything about it before taking a shot at it.
What is Mounjaro?
It is the name of the brand of the medicine that is administered in injectable form. “When used, certain hormones glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) get stimulated from the intestine,” says endocrinologist Dr Sandeep Kharb. Its mechanism of action is basically modeled on these hormones. Insulin release from the pancreas gets increased, and appetite gets suppressed, helping people with type 2 diabetes.
Moreover, the movement of the stomach gets slowed down, allowing food to remain in the stomach for a longer period of time. As a result, satiety gets prolonged, and a feeling of fullness persists. “This way, blood sugar levels can be controlled in a better way and weight loss gets supported,” shares the expert.
Mounjaro for weight loss: Is it approved?
No, Mounjaro for weight loss is not approved by the US Food and Drug Administration. However, a drug called Zepbound, which has the same active drug tirzepatide as Mounjaro, is FDA approved for weight loss and management. The injection can be used for weight management in adults with obesity or overweight with at least one weight-related condition such as type 2 diabetes, high blood pressure or high cholesterol. However, it needs to be used with a low calorie diet and regular physical activity.
How does Mounjaro help in weight loss?
Mounjaro for weight loss is yet to be approved by the FDA, but there are many studies that claim that it is an effective way to manage weight. One such study, published in May 2025 in the New England Journal of Medicine, found that users of tirzepatide (Mounjaro) lost about 20 percent of their body weight in 72 weeks. During that same period, participants on semaglutide (Ozempic) lost about 14 percent.
Here’s how Mounjaro may work in helping people lose weight:
- Dual receptor activation: Mounjaro for weight loss may work, as it activates both the GLP-1 and GIP receptors. While GLP-1 receptors play a role in insulin release and regulation of appetite, GIP receptors are involved in glucose metabolism.
- Slows down digestion: This weight loss drug can slow down the rate at which the food you eat leaves your stomach. This can make you feel full for a longer period.
- Suppresses appetite: “If you take Mounjaro for weight loss, a more selective suppression of appetite occurs specifically for high-calorie foods,” says the expert. For instance, if sweets, fried foods or sugary drinks are consumed while on this medication, significant discomfort may be experienced and so, can discourage further intake of that food item. This means the appetite suppressant effect is selective and especially effective against high-calorie foods.
Mounjaro: Dosage details
Since it is yet to be approved for weight loss, there is no specific dose for people who want to lose weight. However, for diabetes management, the FDA recommends the following:
- The initial dosage is 2.5 mg to be injected subcutaneously once a week.
- It can be increased to 5 mg (once a week) after using the medicine for 4 weeks.
The maximum dosage to lower blood sugar levels is 15 mg subcutaneously once weekly. But a personal consultation with a doctor will help you understand your dosage better.
How to get Mounjaro for weight loss?
Mounjaro for weight loss can be obtained through a prescription, so don’t buy it from a pharmacy without getting approval from your doctor. It is typically prescribed to people with obesity, whose body mass index is more than 30, or those who are overweight (BMI is over 27) with at least one weight-related health condition such as type 2 diabetes.
What are the side effects of Mounjaro for weight loss?
Here are some of the side effects of Mounjaro for weight loss:
- Nausea
- Diarrhea
- Reduced appetite
- Vomiting
- Constipation
- Upset stomach or pain in the abdomen
“These side effects are usually more common in the beginning of the treatment, so there’s nothing to worry about,” says Dr Kharb. They tend to subside over time as the body adjusts to Mounjaro for weight loss.
What are the long-term side effects of Mounjaro for weight loss?
Long-term side effects of Mounjaro for weight loss are not many and rare.
- It has been associated with muscle loss.
- There may be an increased risk of pancreatitis, which is inflammation of the pancreas.
- There is a risk of medullary thyroid cancer, a type of cancer that forms inside the thyroid gland.
- Formation of gallstones, which are the hardened pieces of bile that get formed in the gallbladder.
If you are planning on taking Mounjaro for weight loss, then know the dosage to avoid side effects like nausea and gallstones. It is best to reach out to a doctor before using this anti-diabetes drug to lose weight.
Related FAQs
How much weight can be lost on Mounjaro in 3 months?
Over a period of three months, a weight reduction of 10 to 12 percent may be possible. Around 15 percent reduction in weight may be possible in 6 months.
How to maximise weight loss while on Mounjaro?
In addition to taking the correct dose of Mounjaro, follow a balanced diet instead of dieting. Regular exercise, staying hydrated, getting enough sleep and managing stress can also help to lose weight.
