Switching Pharmacy on Mounjaro: How to Swap Without Missing a Dose

Your dose when you swap pharmacy: start again, stay or move up?

You do not start again. With proof of your current dose and no missed doses, you have two options at a new pharmacy. Stay on the same dose, or move up to the next dose. The new prescriber checks your record and writes the prescription.

• Stay on the same dose. Tell the new pharmacy your dose and the date of your last injection. The Mounjaro SmPC names 5 mg, 10 mg and 15 mg as the recommended maintenance doses. The prescriber decides whether to hold you on 2.5 mg, 7.5 mg or 12.5 mg.
• Move up one dose. The SmPC allows an increase of 2.5 mg after 4 weeks or more on your current dose. Weeks at your old pharmacy count. One KwikPen holds 4 weekly doses, so a finished pen at your current dose equals 4 weeks.
• No skipped steps. The SmPC raises the dose in 2.5 mg increments. A jump from 5 mg to 10 mg in one move sits outside the schedule.
• Move down. Tell the prescriber if side effects are hard to live with. A lower dose is a clinical decision.

The next dose available from each dose

Missed doses change the answer

The SmPC reports stomach side effects mostly during dose increases. A break lowers your tolerance, so prescribers are careful with the dose after missed injections. The SmPC sets no restart rule. The table below pairs the SmPC with a 2023 paper by Whitley, Trujillo and Neumiller in Clinical Diabetes, the American Diabetes Association journal. The paper is expert opinion written for clinicians in the United States during a supply shortage. The paper is not UK guidance, and your prescriber decides.

What to tell the new prescriber

• Your current dose and the date of your last injection.
• How many weekly doses you have taken at this dose.
• Any missed doses, with dates. Give the true dates. A higher dose after a break raises the chance of side effects.
• Side effects on your current dose.
• The dose you want: the same dose or the next dose up.

Ask for the dose decision before you pay. Then compare the price of the dose you will be on, not the dose you are leaving, in the discount price list.

How to swap pharmacy in 8 steps, with timing

1. Count your doses. Day 0. Note your current dose (2.5, 5, 7.5, 10, 12.5 or 15 mg), your injection day and the doses left in your pen. Start the swap with one dose or more left.
2. Collect your proof of supply. Day 0. Photograph your pen box with the dispensing label showing your name, the dose and the date. Save the order confirmations from your current pharmacy.
3. Choose the new pharmacy on the checkout total. Day 0. Use the discount price list for your dose. The list shows the checkout total, including delivery and consumables where charged. Check how the pharmacy treats patients already on treatment in the maintenance directory.
4. Complete the new consultation as an existing patient. Day 0 or 1. Give your current dose and the date of your last injection. Upload your proof when asked. Expect an ID check and a weight and height check.
5. Ask which dose the prescriber will supply. Day 1. Say which dose you want: the same dose, or the next dose up after 4 weeks or more on your current dose. The new prescriber confirms the dose. Ask for the decision before you pay.
6. Order, then wait for approval. Days 1 to 3. Tap a code on the pharmacy's Monj page to copy the code, paste the code at checkout and check the total. Keep your old subscription active until the new pharmacy confirms dispatch.
7. Cancel the old pharmacy in writing. After dispatch. Stop the subscription from your account or by email. Ask for confirmation and keep the reply. Ask for a refund of any cycle charged and not dispatched.
8. Take your next dose on your usual day. Injection day. The pen from the new pharmacy contains the same medicine. Follow the dose on the new dispensing label and your prescriber's instructions.

What a new pharmacy asks for

Pharmacies commonly ask for the items below. Each pharmacy sets its own process. The regulatory points come from the General Pharmaceutical Council (GPhC) guidance for pharmacies providing services at a distance, updated in February 2025.

Timing your order so no dose is missed

Mounjaro is a once-weekly injection. Count back from your next injection day. Approval and dispatch commonly take one to three working days, and next-day tracked delivery is common. Starting 7 days ahead leaves room for a prescriber query or a weekend.

The Mounjaro KwikPen SmPC allows a change of injection day: "The day of weekly administration can be changed, if necessary, as long as the time between two doses is at least 3 days." Ask your prescriber before you move your day.

If you are on your last dose, start the new consultation today.

If a gap opens between your old and new pharmacy

The wording below comes from the Mounjaro SmPC (section 4.2) and the patient information leaflet, both published by Eli Lilly on the electronic medicines compendium. Monj does not give medical advice. Your prescriber decides what you do after a gap.

• Up to 4 days late. The SmPC says to take a missed dose as soon as possible within 4 days after the missed dose.
• More than 4 days late. The SmPC says to skip the missed dose and take the next dose on your regularly scheduled day.
• Catching up. The patient leaflet says: "Do not use a double dose to make up for a forgotten dose. The minimum time between two doses must be at least 3 days."
• A longer break. The SmPC gives no instruction on restarting after several missed doses. The SmPC dosing schedule starts at 2.5 mg and rises in 2.5 mg steps after 4 weeks or more on each dose. A 2023 paper in Clinical Diabetes suggests the same dose after 1 or 2 missed weekly doses and 5 mg after 3 or more. See the dose table. Some pharmacies restart at a lower dose after a break, and each sets its own policy. Speak to your prescriber before you inject again.

Problems when you change pharmacy, and what to do

Eligibility when you switch

The Mounjaro SmPC sets the starting criteria for weight management: a BMI of 30 or more, or a BMI of 27 to under 30 with one weight-related condition or more. The BMI requirements guide covers the thresholds in full.

Pharmacies differ in how they treat someone already on treatment whose BMI has fallen below the starting threshold. Smaller independent pharmacies generally accept existing patients on proof of treatment. Some larger providers apply the starting threshold to switchers. Maintenance applies at any dose. Check the pharmacy's stated maintenance BMI in the maintenance directory before you pay for a consultation. If no policy is listed, ask the pharmacy and get the answer in writing.

What switching costs

• First-order codes. You are a new customer to the new pharmacy, so first-order discounts normally apply. Check the ongoing price too, because you pay the ongoing price from the second month.
• Your old subscription. Cancel before the next billing date, and after your new pen is dispatched.
• Consultation fees. Most online pharmacies include the consultation in the pen price. A few charge separately. The Monj price list shows the checkout total with any separate fee included.
• Delivery and consumables. Some pharmacies include needles and sharps bins and others charge for them. The checkout total in the price list includes these charges.

Why people switch, and what to check for each reason

Guides for the next decision