Some of the most common side effects of Mounjaro are nausea, diarrhea, decreased appetite, vomiting, constipation, indigestion, and abdominal pain. If these persist or get worse, you need to talk to your healthcare provider.
Please note that not all possible side effects can be listed. If any of these or other unexpected side effects are experienced, seek medical attention promptly.
In animal studies, it has been found that Mounjaro and similar drugs may cause thyroid tumors, including thyroid cancer. If there are any symptoms like a lump or swelling in the neck, hoarseness, trouble swallowing, or shortness of breath, these may be symptoms of thyroid cancer.
People who have any personal or family history of medullary thyroid carcinoma (MTC), or who have the endocrine system condition called Multiple Endocrine Neoplasia syndrome type 2 (MEN 2) should not be taking Mounjaro.
Less frequently, Mounjaro may cause serious side effects, including:
- Pancreatitis, caused by inflammation of the pancreas, which can cause severe pain in the stomach area that will not go away, possibly along with vomiting. Pain may spread from the abdomen to the back. If these symptoms present, stop using Mounjaro and call for support right away.
- Low blood sugar (hypoglycemia) is possible if Mounjaro is being used along with another medicine that can reduce blood sugar levels, such as sulfonylurea or insulin. Signs of low blood sugar can include dizziness or light-headedness; sweating; confusion or drowsiness; headache; blurred vision; slurred speech; shakiness; accelerated heartbeat; anxiety, irritability or mood changes; hunger; weakness; or jitters. If these symptoms occur, it is recommended to go to an emergency healthcare facility immediately and tell them what medications you have taken.
- Mounjaro can cause a serious allergic reaction, such as swelling of the face, lips, tongue or throat; problems breathing or swallowing; severe rash or itching;, fainting or feeling dizzy; or very rapid heartbeat. Get medical help right away if any of these symptoms appear.
- Some gallbladder problems have occurred. Report to the healthcare provider right away if there are symptoms of gallbladder problems, such as pain in the upper abdomen; fever; jaundice (yellowing of skin or eyes); or clay-colored stools.
Mounjaro treats adults with type 2 diabetes mellitus. It is not suitable for type 1 diabetes, and has not yet been approved for children under the age of 16.
The drug can lower blood sugar levels, but is not a cure for diabetes. Benefits may only begin to show after the first month. Do not stop taking Mounjaro without talking to a doctor.
Treatment with glucagon-like peptide-1 (GLP-1) agonists produces significant reductions in the key measurement of blood sugar, the hemoglobin HbA1c test. This test measures average blood sugar levels over a three-month period. In trials, patients receiving Mounjaro reached an HbA1c of less than 7 percent, when the average starting HbA1c was between 7.9% and 8.6%. An HbA1c in a normal reading is below 5.7 percent, and diabetes is diagnosed when HbA1c reaches 6.5 percent or above.