Is Mounjaro approved for weight loss?

Mounjaro (tirzepatide) is FDA‑approved as a once‑weekly injection, alongside diet and exercise, to improve blood sugar control in adults with type 2 diabetes. It is not officially approved for weight loss, but many healthcare providers prescribe it off‑label to support weight reduction in people with obesity.

How it works

Mounjaro activates two gut hormones—GIP and GLP‑1—that regulate appetite and digestion. By slowing gastric emptying and signaling fullness to the brain, it reduces calorie intake. It also enhances insulin release to lower blood sugar.

Eli Lilly markets the same active ingredient under the name Zepbound for chronic weight management in adults with a BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 plus at least one weight‑related condition.

Common side effects

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

Other possible effects

  • Burping
  • Fatigue
  • Stomach pain
  • Hair loss
  • Injection site reactions
  • Dizziness

Serious side effects

If you experience any of these, seek medical attention immediately:

  • Allergic reactions: hives, throat swelling, difficulty breathing
  • Thyroid tumors: lump in neck, hoarseness, swallowing trouble
  • Pancreatitis: severe upper abdominal pain, possibly radiating to back
  • Kidney damage: signs of dehydration, reduced urine output
  • Gallbladder issues: severe upper abdominal pain, fever, nausea
  • Hypoglycemia (if combined with insulin or sulfonylureas): shakiness, confusion
  • Vision changes in diabetic retinopathy
  • Worsening depression or suicidal thoughts

Weight loss results

In clinical trials, participants lost an average of 15–20 percent of their starting weight over 72 weeks. Higher doses led over one‑third of participants to lose at least 25 percent of their body weight.

Off‑label use in non‑diabetics

People without diabetes often receive Mounjaro off‑label for obesity management. Zepbound offers the same active ingredient under a weight‑loss‑specific approval.

Insurance coverage

Most insurers do not cover Mounjaro for weight loss, as it is only FDA‑approved for diabetes. Coverage may require prior authorization, and out‑of‑pocket costs can be high. Discount programs may help reduce expense.

Discuss with your provider

Talk to your healthcare professional about whether off‑label use of Mounjaro or Zepbound is appropriate based on your health status, weight goals, and potential risks.

Sources

  • Ania M. Jastreboff et al., Tirzepatide Once Weekly for the Treatment of Obesity, N Engl J Med 2022;387:205–216.
  • Mounjaro (tirzepatide) injection, Eli Lilly & Company. Last updated 11/2024.