What Should a Mounjaro Pen Look Like After 3 Doses? (October 2026)

01 · The core answer

What your Mounjaro pen shows after three doses

After three weekly injections, your pen should contain the final dose of its four weekly doses. Each KwikPen contains four weekly doses, and that does not change with strength: the 2.5mg pen and the 15mg pen both hold four injections.¹

The dose knob is set by turning it until the dose indicator shows your correct dose in the window.¹³ That number is your strength (for example 5mg), not a tally of injections.

So the honest answer is that the pen may look quite similar from one week to the next. The reliable evidence that a dose remains is simple: the knob turns to the full dose in the window. The reliable evidence that it does not is the opposite. If you are comparing your pen with a photo or a forum post, treat that comparison with caution. Pens differ in strength and in how the label is printed.

02 · What to do next

Is your pen behaving normally?

Your pen is behaving normally if the knob turns freely to your full dose in the window and the injection goes as described in the leaflet. The pen is designed so that you cannot dial more than the medicine left inside.¹³ This is a safety feature, not a fault.

Do not try to top it up with a different pen. Keep the pen, note the dates of your injections and contact the pharmacy that supplied it.

If you are worried you are getting fewer doses than you should, speak to your supplier with your dose diary to hand. If you are still planning treatment and want to see what a pen costs, the Mounjaro pen starts at £169.99 for the 2.5mg starting strength at standard price, checked 11 October 2026.

03 · Dial and window

How the dial and dose window work

The KwikPen is set by turning the dose knob until the dose indicator shows the correct dose in the window.

Many people ask how many clicks the pen makes. The answer is that the click count is not the measure. Clicks can feel different from pen to pen and from week to week, and they are not what the leaflet tells you to rely on. The number in the window is.

It also means the window is not a countdown. When you finish an injection, the pen does not display "three used, one left". What changes is the amount of medicine inside, and the pen's mechanism stops you dialling more than that amount.¹³

For the stage right after you inject, our guide to what the pen looks like after an injection covers what you should see on the pen once the dose has been given.

04 · Counting your doses

How to keep track of how many doses are left

The most dependable way to know how many doses remain is to record each injection when you take it. Each KwikPen contains four weekly doses, so a pen started on a given date will run for four weekly injections if you stay on the same day each week.

Practical ways to track it:

• Write the date on the pen label or the carton when you start a new pen.
• Mark each injection on a calendar or in your phone the moment you take it.
• Use a tracking app. Our free companion app, GLPTrackr, is built for tracking a GLP-1 journey and is available on iOS and Android.
• Keep the empty carton and the leaflet together until the pen is finished.

If you inject on the same day each week, at any time of day, with or without food, the schedule is easy to follow. Mounjaro is injected under the skin once a week on the same day each week.1 There is no best time of day: what matters is the same day each week, so pick a day and a time you will remember.

If you ever need to move your injection day, you can, as long as at least 3 days (72 hours) have passed since your last dose.¹ Note the change in your diary so your count stays right.

05 · Fewer doses than expected

Why you might feel you are only getting three doses

A pen is licensed to contain four weekly doses, so getting only three is not what the product is designed to deliver. Before you assume something is wrong, check the common explanations that have nothing to do with the pen.

• Counting error. If a week was missed, delayed or repeated, your mental tally may be off. Check your diary against the calendar.
• A change of injection day. Moving the day can make a pen look as if it has run out early or late when the number of injections is in fact right.
• A mixed-up pen. If you have more than one pen at home, for example at two strengths, make sure you are counting the doses from the same pen.

If your count is right and the pen still gave you fewer doses than it should, keep the pen and the packaging. Contact the pharmacy that supplied it promptly. If you bought from us, our support team is available Monday to Friday, 9am to 5pm, on 0333 207 0413 or at support@everydaymeds.co.uk, and any faulty, damaged or wrong item should be reported within 3 days of delivery.

Also be alert to fakes. Counterfeit pens exist, and the MHRA publishes alerts and runs the Yellow Card scheme for reporting problems.⁷ Genuine pens come from a regulated pharmacy. Anyone offering to supply without a consultation or prescription should be avoided. Our supply comes through official LillyDirect channels direct from Eli Lilly's UK distribution.

06 · Storing a pen in use

Storing the pen between doses

Between your third and final injection, the pen still needs proper storage. Keep Mounjaro pens in a fridge at 2–8°C and never freeze them. Once in use, a pen can be kept out of the fridge not above 30°C for up to 30 days, after which it should be discarded.¹³

Keep the pen cap on to protect it from light, and never use a pen that has been frozen.¹³ Check the date you started the pen, so you know it is within its 30-day in-use window.

If you are travelling, you can fly with Mounjaro. Carry pens in hand luggage, because hold luggage can fall below freezing, ideally in a cool bag with the prescription label or a copy of your prescription.¹³ In-use pens tolerate up to 30 days not above 30°C, so most holidays need no special arrangements. For hot climates use an insulated pouch.

Unopened pens should be kept in the fridge and keep until the expiry date printed on the box. If an unopened pen has been out of the fridge, check with the pharmacy before using it rather than relying on a remembered day limit. Figures circulating online often come from other countries' labels.

07 · Injecting correctly

How to know you injected correctly

You know you have injected correctly when you have followed the pen's instructions for use from start to finish, in a licensed site. Mounjaro is injected under the skin (subcutaneously). Licensed sites are the stomach area (at least 5cm from the belly button), the front of the thigh, or the back of the upper arm if someone else gives the injection. Rotate the site with each dose.¹³

Readers often ask whether they must pinch the skin, how long to hold the pen in place and whether there is a wrong way to give a subcutaneous injection. For these technique details, follow the instructions in the patient information leaflet that comes in your box rather than a video or a forum post.

If you are not sure the dose went in, do not inject again straight away to make up for it. Instead, speak to a prescriber or pharmacist. Do not take an extra dose: the pen is designed around a single weekly dose.

Every order from us includes needles, a sharps bin and injection guidance, and the prescribing team offers side-effect support if you need it. Our guide to how the pen should look after the first dose and the page on what a pen looks like after a single dose are useful if you want to compare your pen across the weeks.

08 · Pen won't turn

If the dial will not turn

If the dial will not turn to a full dose earlier than you would expect from your diary, there are a few things worth checking before contacting anyone.

• Check you are dialling toward your correct dose number, not trying to go past it.
• Check you have not already used the final dose in a week you forgot to record.
• Check the pen is the one you think it is, and not an older pen.

Do not force the knob. For a fuller walk-through, see our page on what to do when the Mounjaro pen won't turn, and for how a finished pen appears, see what an empty Mounjaro pen looks like.

09 · Where you are in treatment

What three doses means for your treatment

Three weekly injections is early. Everyone starts Mounjaro on 2.5mg once a week, and this starting dose is about letting your body adjust, not about weight loss itself. After at least 4 weeks the dose increases to 5mg, and can then step up by 2.5mg at a minimum of 4-week intervals up to a maximum of 15mg weekly, depending on how you respond and tolerate it.¹

After your first pen, your prescriber reviews how you are getting on and decides whether to move you up.

Do not judge progress by the pen. Weight loss on Mounjaro is gradual by design. The first weeks on 2.5mg are an adjustment phase and losses are usually modest. Most measurable progress builds from 5mg onward, month by month. Trials measured results at 72 weeks, so think in months, not days.²

For reference, in the SURMOUNT-1 trial, people taking tirzepatide alongside diet and exercise lost on average 15% of their body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone. These are trial averages and individual results vary.²

Mild nausea, altered appetite and tiredness in the first days after each injection are the commonest early effects and usually settle. If anything new or worrying appears, discuss it with your prescriber and report side effects through the Yellow Card scheme.⁷ Our wider weight loss clinic pages cover what to expect month by month.