1. What is it?
Tirzepatide is a laboratory-made peptide that stimulates receptors for two gut hormones: GIP and GLP-1. A receptor is a site through which a cell receives a signal. This action is used to treat metabolic disorders. The substance's name and the medicine's name mean different things: tirzepatide is the active ingredient, while Mounjaro and Zepbound are names of specific products with a defined composition, quality control and information about their uses. [150] [154]
2. Why do people turn to it?
Tirzepatide is used primarily to treat type 2 diabetes and excess body weight. In the European Union, its weight-management indication covers adults with obesity, or overweight and an associated condition, alongside changes to diet and activity. In the USA, Zepbound is also indicated for moderate or severe obstructive sleep apnoea in adults with obesity. This condition involves repeated episodes of restricted or stopped breathing during sleep. [151] [155]
3. How does it work?
Tirzepatide helps the body release insulin in response to meals and affects appetite regulation. It may make smaller portions easier to eat by reducing troublesome hunger. This does not mean physically removing fat or being able to eat without limits. Its effects also include the rate of stomach emptying. The effects on digestion help explain both some benefits and the nausea or fullness that can occur during treatment. [150] [151]
4. What do studies actually show?
SURMOUNT-1 enrolled 2,539 adults with obesity, or overweight and an additional health problem, who did not have diabetes. After 72 weeks, average weight loss in the groups receiving tirzepatide was about 15–21%, depending on the study group. Participants also received support with eating fewer calories and increasing physical activity. The reported weight loss concerns treatment under those conditions. These results came after more than a year of follow-up, not during the first few weeks. An average describes the whole group: individual improvements varied, and some people stopped participating or discontinued treatment. The study assesses obesity treatment in the population described; it does not set a weight target for someone who does not meet the criteria for that condition. [152] [192]
5. What do we still not know?
A finding in people without diabetes does not precisely predict the result in someone with diabetes, other conditions or a different course of treatment. Time matters too: losing weight and later maintaining it are two separate challenges. Researchers therefore study different approaches to ongoing treatment. An average weight reduction should not become a promise of a particular number of kilograms for every patient. [152] [153]
6. What are the risks?
The most common symptoms affect the digestive tract: nausea, diarrhoea, vomiting and constipation. Vomiting or diarrhoea can cause dehydration. Severe, persistent abdominal pain needs urgent assessment, including for pancreatitis. The risk of low blood sugar increases with certain other diabetes medicines. Tirzepatide is not recommended during pregnancy; pregnancy plans and all medicines being taken should be discussed with the treating doctor. [151]
7. Is it an approved medicine?
As of 3 November 2026, tirzepatide is an ingredient in approved medicines, but their authorised uses depend on the country and product. European Mounjaro information remains the appropriate reference for patients in Poland. The US approval of Zepbound for sleep apnoea does not automatically create the same separate indication in the EU. Treatment decisions concern a diagnosed condition and a specific medicine, rather than the substance's popularity alone. [150] [155]
8. What is new in research?
SURMOUNT-MAINTAIN, about maintaining achieved weight loss, was published in May 2026. Participants completing an initial 60 treatment weeks were followed for another year under different continued-treatment strategies. The study expands knowledge of maintenance, but does not mean everyone can reduce treatment independently. Findings concern a selected group following lengthy prior treatment under defined study procedures. [153]
Where does this information come from?
References link to the publications and documents used. Each source includes its material type and what was reviewed; findings concern the substance, form and study population described.
Show sources and how they were checked
- Mounjaro
EMA; current product page accessed 3 November 2026; full overview of indications and mechanism. Accessed: 3 November 2026.
- Mounjaro: EPAR - Product information
EMA; version dated 21 September 2026; indications, warnings and pregnancy information reviewed. Accessed: 3 November 2026.
- Tirzepatide Once Weekly for the Treatment of Obesity
Randomised phase III SURMOUNT-1 trial; published online 04.06.2022; PubMed abstract read · DOI: 10.1056/NEJMoa2206038. Accessed: 03.11.2026.
- FDA Approves First Medication for Obstructive Sleep Apnea
FDA; decision dated 20 December 2024; full announcement reviewed. Accessed: 3 November 2026.
- FDA Approves New Medication for Chronic Weight Management
FDA; decision dated 8 November 2023; full announcement reviewed, indication and medicine name used. Accessed: 3 November 2026.
- Clinical Data, Safety & Study Design | Zepbound® (tirzepatide)
Lilly · manufacturer material; SURMOUNT-1 study conditions reviewed, including nutrition and physical-activity support. Accessed: 3 November 2026.
- Tirzepatide for maintenance of bodyweight reduction in people with obesity in the USA (SURMOUNT-MAINTAIN): a multicentre, double-blind, randomised, placebo-controlled trial
Randomised clinical trial; published online 12 May 2026; PubMed abstract reviewed · DOI: 10.1016/S0140-6736(26)00656-2. Accessed: 3 November 2026.