How long do Mounjaro side effects last?
Mounjaro (tirzepatide) is an injectable GIP and GLP‑1 receptor agonist approved for type 2 diabetes and, under the name Zepbound, for weight loss in obesity. Side effects often appear when starting or increasing the dose. Most gastrointestinal effects—nausea, diarrhea, abdominal pain—typically resolve within days to weeks. Eating smaller, bland meals more frequently may help. Persistent or severe symptoms should be discussed with a healthcare professional.
Common side effects
- Nausea
- Diarrhea
- Decreased appetite
- Vomiting
- Constipation
- Indigestion
- Stomach pain
Other mild side effects
- Injection site reactions
- Fast heartbeat
- Bloating and burping
- Heartburn (GERD)
- Hair loss
Serious side effects
These may last longer and require immediate attention. Call your healthcare provider or seek emergency help (911) if you experience:
- Severe allergic reactions (anaphylaxis): hives, throat swelling, breathing difficulty
- Signs of thyroid tumors: lump in neck, hoarseness, difficulty swallowing
- Pancreatitis: severe upper abdominal pain radiating to the back, with or without vomiting
- Kidney injury or failure: reduced urination, signs of dehydration from vomiting/diarrhea
- Gallbladder issues: intense upper abdominal pain, fever, nausea, vomiting
- Hypoglycemia (if on insulin or sulfonylureas): shakiness, sweating, confusion, weakness
- Vision changes in diabetic retinopathy
- Worsening depression or suicidal thoughts
When to call your doctor
Contact your provider if side effects persist despite dietary adjustments or OTC remedies. Urgent signs include severe allergic reactions, thyroid tumor symptoms, or intense abdominal pain.
Alcohol and Mounjaro
There are no known direct interactions, but alcohol can worsen nausea, vomiting, diarrhea, indigestion, and bloating. It may also mask hypoglycemia symptoms. Discuss safe alcohol use with your provider.
Who should avoid Mounjaro?
People with a personal or family history of medullary thyroid carcinoma or MEN 2 syndrome should not use Mounjaro due to an increased risk of thyroid tumors (Boxed Warning).
Pregnancy and breastfeeding
Mounjaro may harm an unborn baby. If pregnant or planning pregnancy, consult your provider. Oral contraceptives may be less effective; use alternative contraception for 4 weeks after starting or each dose increase. Safety in breastfeeding is unknown; discuss feeding options with your provider.
Sources
- Mounjaro (tirzepatide) injection, Eli Lilly & Company. Last updated 11/2024.