Mounjaro weight loss injections: a practical guide for people in Leeds

Step 1, clinical assessment: what happens before you inject anything

Before a single pen is dispensed, a prescriber reviews your health history. For anyone using a regulated online pharmacy, that means completing a structured medical questionnaire covering your BMI, current medicines, relevant conditions and whether there are any clinical reasons Mounjaro would not be appropriate for you. At nume, a GPhC-registered Independent Prescriber reads every consultation personally on the day it is submitted, your answers go to a clinician, not a screening algorithm.

Identity and weight are verified too. This matters not just as a formality but because starting dose, titration and ongoing safety depend on accurate baselines. If you are already on Mounjaro through another provider and want to transfer, your current dose and prescription history will be reviewed before treatment continues. People in Leeds sometimes ask whether they need a local GP referral, for private treatment, you do not, though our prescribers notify your GP in line with GPhC guidance so your wider care team stays informed.

Certain situations mean Mounjaro is not suitable: pregnancy, breastfeeding, or actively trying to conceive; anyone under 18; and a personal or close family history of medullary thyroid carcinoma or a condition called MEN2. A prescriber works through all of this during assessment. The NHS tirzepatide medicines page has a clear summary of the contraindications worth reading before you consult.

Step 2, starting at 2.5 mg: the first four weeks

The first pen contains four weekly doses of 2.5 mg. This starting dose exists for one reason: tolerability. It lets your digestive system adapt to the medicine before the therapeutic dose begins. Some people feel very little at 2.5 mg; others notice nausea or a significant drop in appetite almost immediately. Both are normal responses.

Injection technique is straightforward once you have done it once. You choose a site (the abdomen, front of the thigh, or outer upper arm) clean it, and use the KwikPen to inject under the skin. The pen is pre-filled and pre-set; there is no drawing up of liquid and no manual needle-plunging. Rotate injection sites each week to avoid irritation at the same spot.

If you order through a GPhC-registered pharmacy and your consultation is approved before midday on a working day, treatment is dispatched the same day. What actually arrives is a plain, unbranded box via DPD with tracking sent to your phone, inside, your KwikPen stored in the manufacturer's packaging and ready for the fridge. Storage is simple: 2–8°C in the refrigerator. For exact guidance on what to do if a pen has been left out at room temperature, the full Mounjaro injection guide covers storage windows in detail, and the Patient Information Leaflet included in your pack is the definitive reference.

Step 3, titration: how the dose increases over time

After four weeks at 2.5 mg, a prescriber reviews progress and tolerance. If the medicine is being well tolerated, the dose typically moves up in 2.5 mg steps at four-week intervals, through 5 mg, 7.5 mg, 10 mg, 12.5 mg, up to a maximum of 15 mg. Not everyone reaches the highest dose; the right maintenance dose is whatever delivers meaningful results without unacceptable side effects, and that varies between individuals.

Decisions about titration are made by your prescriber, not by you independently. That is not a bureaucratic point, it reflects the fact that dose increases carry a renewed risk of GI side effects, and in some situations slowing the titration schedule is the better clinical call. The question of how long Mounjaro takes to work is one our prescribers hear regularly; meaningful weight change generally becomes apparent in the first eight to twelve weeks, with results building through the titration period.

People sometimes ask about cost as doses increase, since higher-dose pens have a different list price. The Mounjaro cost page sets out what is included in private treatment pricing and how to think about overall value rather than headline pen price alone.

Side effects to know about, and when to get medical help

Most people on Mounjaro experience some gastrointestinal effects, particularly in the early weeks: nausea is the most common, followed by changes in bowel habit, burping, reflux and fatigue. These typically ease as your body adapts and often reduce significantly after the first few weeks at any given dose. Eating smaller meals, staying well hydrated and avoiding high-fat or very rich food can help manage them.

There are rarer but more serious effects to be aware of. On 29 January 2026 the MHRA issued a Drug Safety Update drawing specific attention to acute pancreatitis as an infrequent but serious risk with GLP-1 medicines: if you develop severe stomach pain that does not ease and radiates towards your back, with or without vomiting, seek urgent medical attention and tell the treating clinician you are on tirzepatide. The MHRA Yellow Card scheme allows patients to report any suspected side effect directly to the regulator, which contributes to ongoing safety monitoring for newer medicines like this one. Mounjaro carries a Black Triangle (▼) designation, meaning it is under additional surveillance.

Signs that need prompt attention also include symptoms of gallbladder problems, dehydration from prolonged vomiting or diarrhoea, or any allergic reaction. Your prescriber and the Patient Information Leaflet are the right sources for a full list, and our Mounjaro weight loss injections page covers what to expect across the full course of treatment. If you want to understand how the active ingredient works across different products, our guide to weight loss injections containing tirzepatide explains the options available and how they compare.

If you have questions between orders, aftercare support is available seven days a week. When you are ready to take the next step, start your free consultation and a prescriber will assess whether Mounjaro is clinically appropriate for you.