Mounjaro benefits and side effects explained: All you need to know

Obesity is a major health concern in the world, as millions of people have excessive fat deposits in their bodies. In 2022, 890 million people were found to be living with obesity, according to the World Health Organization. So, it comes as no surprise that pharmaceutical companies and government agencies globally are trying to come up with a solution. That has brough weight loss drugs into the picture. Most of these prescribed medicines help by mimicking the hormones that play a key role in regulating appetite and hunger. Mounjaro is one such medication, which is used to manage type 2 diabetes and also has weight loss benefits. Know all about the benefits and side effects of Mounjara, a weekly injectable drug, before using it to lose weight.

What is Mounjaro?

Mounjaro is the brand name for tirzepatide, a once-weekly injectable medication approved by the US Food and Drug Administration for type 2 diabetes. It is also used off-label for weight loss, which means it is prescribed for a purpose other than what it’s been approved for.

“Unlike earlier GLP-1 agonists like semaglutide, which is sold under different brands, including Ozempic, Mounjaro acts on two incretin hormones GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1),” says endocrinologist Dr Archana Juneja. This way, it enhances its efficacy for both glycemic control and weight loss.

What are the benefits of Mounjaro?

Here are the key benefits of Mounjaro:

1. Manages diabetes

It helps in managing type 2 diabetes by increasing the production of insulin in the body. This in turn helps in lowering blood sugar, as the amount of sugar your liver produces decreases. “It stimulates the pancreas to release more insulin in a glucose-dependent manner, meaning it primarily works when blood glucose levels are high, reducing the risk of hypoglycemia,” explains the expert.

2. Helps with weight loss

Mounjaro has demonstrated significant weight reduction in non-diabetics as well. A new study, presented at the European Congress on Obesity in Spain in May 2025, found that a weekly dose of tirzepatide can lead to significant and consistent weight loss for up to 3 years in obese or overweight adults who are not diabetics. “This medicine works on the brain’s hypothalamus, which controls hunger. It helps to suppress appetite and slow down gastric emptying, leading to early satiety and aiding weight loss,” says the expert.

Mounjaro doses

The doses increase gradually, but make sure to follow your doctor’s advice.

• The recommended starting dose is 2.5 mg, which needs to be injected under the skin of your stomach, thigh, or upper arm once weekly, as per the FDA.
• Four weeks later, the dose will be increased to 5 mg.
• The maximum dosage is 15 mg, which should be injected subcutaneously once weekly.

If you miss a dose, a jab needs to be given as soon as possible within 4 days after the missed dose.

Does Mounjaro cause hair loss?

Hair loss is not a known or common side effect of Mounjaro itself. However, rapid weight loss, which is common with tirzepatide, can lead to telogen effluvium, a temporary hair loss problem. “This type of hair loss is usually reversible and not directly tied to the weight loss drug’s mechanism,” says Dr Juneja. If you experience hair loss while taking Mounjaro, you should be checked for nutritional deficiencies like iron, zinc, vitamin B12 and protein.

What are the side effects of Mounjaro?

Here are some of the side effects of Mounjaro:

• Nausea: It is a common side effect, experienced when you start taking this weight loss drug. “It is often due to the delayed gastric emptying caused by the medication, and usually improves as the body adjusts to the drug,” says the expert.
• Vomiting: It occurs in some people, particularly if the dose is increased too quickly. It’s the body’s response to changes in digestion and appetite regulation.
• Diarrhea: Loose or frequent stools can result from changes in gut motility, which is the stretching of the muscles in the gastrointestinal tract.
• Constipation: If not diarrhea, some people may experience slowed bowel movements or have difficulty passing stool due to changes in digestion.
• Indigestion: A feeling of discomfort or burning in the upper abdomen after eating may be felt while using Mounjaro.
• Pancreatitis: Inflammation of the pancreas is a rare, but serious side effect of this weight loss drug. It can lead to severe abdominal pain, nausea and vomiting.
• Hypoglycemia (low blood sugar): Mounjaro alone has a low risk of causing hypoglycemia. “However, if used in combination with insulin or sulfonylureas (anti-diabetic medications), the risk increases. Sweating, dizziness and confusion are some of its symptoms,” says the expert.
• Liver toxicity: It is rare, but hepatotoxicity, also known as liver toxicity, may be associated with tirzepatide use. During a study, published in the European Journal Of Case Reports In Internal Medicine, researchers found that liver toxicity was experienced after escalating doses of tirzepatide.