> ## Documentation Index > Fetch the complete documentation index at: https://docs.hi-doctor.ai/llms.txt > Use this file to discover all available pages before exploring further. # Mounjaro (tirzepatide) > What tirzepatide is, how the weekly injection and dose schedule work, what SURMOUNT-1 measured, and who a doctor rules out. Mounjaro (tirzepatide) is a once-weekly injection for weight management. It copies two gut hormones — GIP and GLP-1 — which together reduce appetite, slow how quickly the stomach empties, and help steady blood sugar. It is authorised across the EU and prescribed by licensed doctors when clinically appropriate. ## What it is Tirzepatide is a dual receptor agonist: it activates the GIP and GLP-1 gut-hormone receptors at the same time, with no glucagon component. Mounjaro is centrally authorised, so a single EU authorisation covers all 27 member states, and it is the only tirzepatide brand authorised in the EU. It holds both a diabetes indication and a weight-management indication under the same name. Alongside the single-dose pre-filled pen, the Spanish register also lists multi-dose KwikPen and vial presentations at every strength. ## How it works Both GIP and GLP-1 receptors sit in the brain areas that regulate appetite. Activating them reduces energy intake and appetite by increasing feelings of satiety and fullness, and by decreasing feelings of hunger. Tirzepatide also delays gastric emptying, so food leaves the stomach more slowly after a meal, increases insulin release in a glucose-dependent way, and lowers glucagon. The weight change comes mainly from eating less, and is mostly a loss of fat mass. Acts on two gut-hormone receptors at once rather than one. Slows stomach emptying and helps regulate the insulin response. A chronic treatment for as long as it is beneficial and safe. ## What it's authorised for Type 2 diabetes that is not sufficiently controlled in adults, alongside diet and exercise — either on its own when metformin is inappropriate, or combined with other diabetes medicines. Weight management in adults with a BMI of 30 kg/m² or more, or a BMI of 27 to under 30 kg/m² with a weight-related health condition such as high blood pressure, high cholesterol, sleep apnoea or cardiovascular disease, alongside a reduced-calorie diet and increased physical activity. ## What the studies reported The EMA marketing authorisation has been valid across the EU since 15 September 2022, under EMEA/H/C/005620. The pivotal trial, **SURMOUNT-1**, was peer-reviewed, enrolled 2,539 participants and ran for 72 weeks (DOI 10.1056/NEJMoa2206038, [ClinicalTrials.gov · NCT04184622](https://clinicaltrials.gov/study/NCT04184622)). It was a separate trial with its own population, sites and placebo response. A readout is not the same as peer-reviewed publication — every NCT identifier here links to its ClinicalTrials.gov record. ## Dose schedule The starting dose is low, and increases are doctor-supervised and step-wise. This is the starting dose to help the body adjust. It is not increased during this period. The doctor may adjust the schedule based on how you are responding. Building up to a maintenance dose between 2.5 and 15 mg a week, set by the reviewing doctor. A loss of 5% or more of starting weight at 3 months is considered a good response. The doctor reassesses every 3 months and decides, with you, whether to continue, adjust or stop. Discontinuation is gradual and paired with a maintenance plan. ## Taking it day to day * **Pick one day each week** and inject on the same day, at a time you can keep to. * **Store pens in the fridge** (2–8°C) while unused. Once a pen is in use, keep it below 30°C for up to 30 days, and do not freeze it. * **Check the pen before use.** * **Inject into the tummy, thigh or arm**, just under the skin. * **Rotate the injection spot every week** rather than using the same site repeatedly. * **Missed dose — the four-day rule:** if a dose is missed, it can still be taken within 4 days. After 4 days, skip it and take the next dose on the regular scheduled day. * **Know how long a pen lasts** before starting a new one. ## What has been reported | Effect | Frequency | | --------- | ----------- | | Nausea | Very common | | Diarrhoea | Very common | Severe stomach pain that does not go away can signal pancreatitis and needs urgent medical attention — it is not a symptom to wait out. ## Who it is not suitable for A doctor rules Mounjaro out where it is contraindicated or where a listed authorised indication does not apply — the eligibility checks run on submission of your [consultation](/essentials/how-it-works), not afterwards. The full Mounjaro treatment guide — injection technique in more detail, storage, and a day-by-day dose table — is published at [hi-doctor.ai/guides/mounjaro](https://hi-doctor.ai/guides/mounjaro). ## How Hi-Doctor handles it A questionnaire covering BMI, medical history and current medication is reviewed by an EU-licensed doctor, who decides whether Mounjaro or another [weight-loss option](/essentials/treatments) is appropriate. Cost of the medical consultation is set out on [pricing](/essentials/pricing); the medicine itself is paid separately at a pharmacy. ## Start a consultation Answer the weight-loss questionnaire and a registered doctor reviews it. They decide whether treatment is appropriate, which one, and at what dose — and declining is a normal outcome. See [what it costs](/essentials/pricing) and [how the review works](/essentials/how-it-works). This page is reference information, not medical advice and not a prescription. Whether a medicine is appropriate for you is decided by a registered doctor after reviewing your consultation.