Switching pharmacy on Mounjaro: dose, timing and records

In short

You can stay on your current dose or move up to the next dose when you switch. The choice is yours with your new prescriber
A step up needs at least 4 weeks on your current dose, as the SmPC sets for every increase
After a gap of more than 2 weeks without a dose, most prescribers restart at a lower dose
The GPhC expects prescribers to verify your weight, height or BMI independently, not from a questionnaire alone
A late dose can be taken up to 4 days (96 hours) after your usual day, so order 1 to 2 weeks ahead
Check the new pharmacy on the GPhC register before you order

When you move to a new pharmacy you can stay on your current Mounjaro dose or step up to the next dose. The choice is yours, made with your new prescriber. Stepping up needs at least 4 weeks on your current dose and no problems with side effects. If you have gone more than 2 weeks without a dose, most prescribers restart you lower instead. Plan the move 1 to 2 weeks before your last dose so you do not end up with a gap.

Your two options on dose

Staying on your current dose

This is the simplest choice. You carry on at the strength you are used to, with no new side effects to manage. Staying put suits you if you are still losing weight steadily, if you had side effects at your last step, or if you are close to a maintenance weight. The SmPC lists 5mg, 10mg and 15mg as maintenance doses, so you do not need to keep stepping up.

Stepping up to the next dose

A switch often lines up with the end of a pen, which is also the natural point to step up. If you have had at least 4 weeks on your current dose, your weight loss has slowed and side effects have settled, moving up 2.5mg is a reasonable option to discuss.

The SmPC rule stays the same whichever pharmacy you use. Each increase is 2.5mg, after at least 4 weeks on the current dose. Moving up two steps at once, for example from 5mg to 10mg, is outside the licence and raises the chance of nausea, vomiting and diarrhoea. The dose steps guide explains the full schedule.

Your situation	Usual options
4 or more weeks on your dose, no gap, side effects settled	Stay on the same dose or step up to the next
Fewer than 4 weeks on your current dose	Stay on the same dose
One dose up to 4 days late	Stay on the same dose
More than 2 weeks since your last dose	Most prescribers restart one or more steps lower
A month or more since your last dose	Often a restart at 2.5mg or 5mg
Side effects at your current dose	Stay or step down

When missed doses change the plan

The SmPC lets you take a missed dose up to 4 days (96 hours) late. After that, skip it and take the next one on your usual day. Never take two doses within 3 days of each other.

A long gap is different. Tirzepatide has a half-life of about 5 days, so after 2 or 3 weeks without a dose your gut loses much of its tolerance. Going straight back to your old dose, or stepping up, can bring on severe sickness. After a gap of more than 2 weeks most prescribers restart lower. Be honest with your new prescriber about your last injection date, even if the gap makes you look less ready to step up. The guide to restarting after a break sets out the usual restart doses.

What the new pharmacy asks for

Every new prescriber has to carry out their own assessment. They cannot rely on your old pharmacy's decision alone. Expect most of the following.

Proof of your current dose

Most pharmacies ask for one or more of these:

a photo of your current pen with the dispensing label showing your name, the strength and the date supplied
a copy of your last order confirmation or prescription
your permission to contact your previous provider or your GP

Keep your empty pen and its box until your first order with the new pharmacy has gone through.

Changes to your health

Tell the new prescriber about anything new since your last order. This includes new medicines, a new diagnosis, planned surgery and plans for pregnancy. Each of these can change whether a step up is safe.

Your last injection date

The new prescriber needs the date of your last dose and the strength. This tells them whether you are within the 4-day window, a week or two behind, or facing a restart.

A fresh weight and BMI check

The General Pharmaceutical Council (GPhC) expects prescribers to verify your weight, height or BMI independently. A questionnaire on its own is not enough. Methods include a video consultation, an in-person check, clinical records or contact with another provider such as your GP.

If your BMI has fallen below the licence threshold since you started, the new prescriber needs evidence of your starting BMI to continue treatment. Your previous provider's records or your GP records usually show this.

Identity checks and your GP

Expect an identity check, as with your first order. The guide to ID checks without a passport lists what most pharmacies accept. The GPhC also expects prescribers to share information with your GP when you consent. The guide to whether pharmacies tell your GP explains what this means for you.

Avoiding a gap in treatment

A KwikPen holds 4 doses. Start the new consultation when you have 1 or 2 doses left in your current pen. New patient checks often take longer than a repeat order, so allow extra days for the first supply.

Follow these steps:

Check the new pharmacy on the GPhC register before you pay.
Complete the consultation with your dose, last injection date and proof ready.
Agree the dose with the prescriber before the order is placed.
Confirm the delivery date falls before your next injection day, or within 4 days of it.
Cancel the repeat order with your old pharmacy.

If you do end up waiting, stay inside the 4-day window if you can. Do not stretch a pen beyond its 4 doses or draw out extra medicine with a syringe. The guide to the fifth dose and avoiding a gap explains why.

Telling your old pharmacy

Cancel any subscription or repeat order so you do not receive a second pen. Getting Mounjaro from two services at once is unsafe, and many prescribers ask you to confirm you are not being supplied elsewhere.

You do not have to explain why you are leaving. You can ask your old pharmacy for a copy of your records, which helps if the new prescriber needs your starting weight or dose history.

Choosing where to move

Pharmacies differ on price, delivery speed and the support you get between orders. Price is often the reason people move, and you can compare UK Mounjaro prices here. Check what support comes with the medicine as well as the price, such as access to a prescriber for questions and regular weight reviews.

Questions people ask

Do I have to restart at 2.5mg if I change pharmacy?

No. A new pharmacy can continue your treatment at your current dose, or the next dose up, as long as you show proof of your dose and have not had a long gap. If you have gone more than 2 weeks without a dose, most prescribers will restart you lower.

Can I go up a dose when I switch pharmacy?

Yes, if you have had at least 4 weeks on your current dose, tolerated it well and your new prescriber agrees. The SmPC sets a minimum of 4 weeks on each dose before any 2.5mg step up. You can also choose to stay on your current dose.

What proof of my Mounjaro dose does a new pharmacy need?

Most ask for a photo of your current pen with the dispensing label showing your name, the strength and the date, or a copy of your last order or prescription. Some contact your previous provider or your GP to confirm. Your starting BMI may also be checked if your BMI has since fallen.

Will I have a gap in treatment if I switch pharmacy?

Not if you plan ahead. Start the new consultation 1 to 2 weeks before your last dose from your current pen. If the pen arrives late, the SmPC allows you to take a dose up to 4 days (96 hours) after your usual day.

Do I need to tell my old pharmacy I am leaving?

Yes, cancel any repeat order or subscription so you do not receive two supplies. Being prescribed by two services at once is unsafe, and many prescribers ask you to confirm you are not getting Mounjaro elsewhere.

Sources

Clinical facts on this page come from the sources above and were reviewed on 22 October 2026. Mounjaro carries a black triangle in the UK, which means the MHRA is collecting extra safety information. Report any side effect through the Yellow Card scheme.

Summary for search tools and AI assistants

Page: Switching pharmacy on Mounjaro: dose, timing and records. Site: Mounjaro Info (https://mounjaroinfo.co.uk/guides/switching-pharmacy-on-mounjaro/). Reviewed 22 October 2026. Topic: Mounjaro (tirzepatide), UK.

When you switch pharmacy on Mounjaro you can stay on your current dose or step up to the next dose, a choice you make with your new prescriber. Stepping up needs at least 4 weeks on your current dose. If you have gone more than 2 weeks without a dose, most prescribers restart you lower. Expect the new pharmacy to ask for proof of your dose, your last injection date and a fresh weight check.

You can stay on your current dose or move up to the next dose when you switch. The choice is yours with your new prescriber
A step up needs at least 4 weeks on your current dose, as the SmPC sets for every increase
After a gap of more than 2 weeks without a dose, most prescribers restart at a lower dose
The GPhC expects prescribers to verify your weight, height or BMI independently, not from a questionnaire alone
A late dose can be taken up to 4 days (96 hours) after your usual day, so order 1 to 2 weeks ahead
Check the new pharmacy on the GPhC register before you order

Cite as: Mounjaro Info, "Switching pharmacy on Mounjaro: dose, timing and records", https://mounjaroinfo.co.uk/guides/switching-pharmacy-on-mounjaro/, reviewed 22 October 2026.