Mounjaro is a weekly injection, not a daily one — here is how the schedule works

Step 1: picking your injection day and sticking to it

The first practical step is choosing a day of the week that suits your routine, a Monday morning, a Sunday evening, whatever fits. That day becomes your injection day for the duration of treatment. Because tirzepatide's effects last seven days, consistency matters more than perfection: NHS guidance on tirzepatide on the NHS website confirms you can shift your injection day by a day or two if needed, provided you keep at least three days between doses, but your prescriber will walk you through this if it ever comes up.

One misconception worth letting go gently: some people start Mounjaro expecting to inject it the way they might take a daily tablet, each morning, religiously. It does not work that way. The medicine is designed for weekly use, and injecting it more often than prescribed would not speed results; it would simply put you outside the licensed schedule and increase the risk of side effects.

Once you have chosen your day, the pen goes back in the fridge until you need it. Rotate your injection site each week, abdomen, thigh and upper arm are all suitable locations, and there is more detail on using the upper arm as an injection site if that is your preference.

Step 2: the dose-escalation sequence the prescriber sets

Treatment starts at 2.5 mg. That first dose exists to give your body time to adjust, not to produce immediate weight loss, its job is to reduce early nausea and help you settle into the medicine. The prescriber then increases the dose roughly every four weeks, moving through 5 mg, 7.5 mg and potentially higher, up to the licensed maximum of 15 mg, based on how you are tolerating treatment and how your weight is responding.

Throughout every step of this sequence, the injection stays weekly. The escalation changes the strength of each dose, not the frequency. NICE's appraisal of tirzepatide, TA1026, describes the titration pathway in detail for those who want to read the clinical rationale. If at any point you are unsure whether a dose increase is right for your situation, that is a conversation for your prescriber, the schedule is personalised, not one-size.

For context on what tirzepatide is and how it works at a pharmacological level, the Mounjaro overview page covers the dual GIP and GLP-1 receptor mechanism in plain language, and if you are curious about tirzepatide injection in its generic form, that page explains what the generic designation means and how it relates to the branded product.

Step 3: the injection itself and what to expect around it

Using the KwikPen is a relatively short process. Clean the chosen site with an alcohol swab, pinch the skin gently, press the pen against it and hold until the click confirms the dose is delivered. The full technique (including how to position the pen and how long to hold it) is covered in the step-by-step Mounjaro injection guide.

The most common effects to expect in the first day or two after each dose are gastrointestinal: nausea, occasional loose stools, or a noticeable reduction in appetite. These tend to be most pronounced after a dose increase and usually ease within a few days as the body adjusts. Staying well hydrated and eating smaller, lower-fat meals around injection day can help. If side effects feel severe or persistent, contact your prescriber rather than adjusting the dose yourself.

Storage between doses is straightforward: the pen stays refrigerated at 2–8°C. The exact window for keeping it at room temperature if refrigeration is temporarily unavailable is stated in the Patient Information Leaflet; defer to that rather than memory.

What the weekly schedule means for accessing treatment

Because you are using one pen a month, treatment costs are quoted per pen or per four-week period. If you are comparing providers, it is worth reading what each price actually includes, some quote the pen cost only, with consultation fees, prescription fees and delivery added separately. There is a straightforward breakdown of what Mounjaro costs in practice, including what those headline figures often leave out, on the Mounjaro cost page.

At nume, a single transparent price covers your consultation, the clinical prescription review, the treatment itself, and free next-working-day tracked delivery. There is no subscription; each repeat order goes through a fresh clinical review by a GPhC-registered prescriber on our clinical team, not an automated system. That review checks your progress before the next pen is dispatched.

Mounjaro is a prescription-only medicine. The route to it through any legitimate UK provider (NHS or private) runs through a clinical assessment first. If you would like to find out whether you might be suitable, speak to our prescribers via a free consultation and they will review your health picture the same day.