Tirzepatide delivered: what to check before your pen arrives

You've just received your delivery, now what?

You open the door to a DPD driver, take the box inside, and feel a mix of relief and nerves. That's a completely understandable place to be. Tirzepatide is a significant step, and the practical details deserve more attention than they usually get in the rush of the moment.

First, check the packaging. A genuine Mounjaro KwikPen arrives factory-sealed inside a carton, with a batch number, expiry date, and the Eli Lilly branding intact. The pen should feel cool to the touch if it's been shipped correctly. If the box looks tampered with, the pen is warm, or anything about it gives you pause, put it aside and call the dispensing pharmacy before using it. The MHRA's Yellow Card scheme is also the right place to flag anything that looks wrong, both for your safety and to protect others.

Once you're satisfied the pen is intact and cold, transfer it to the fridge immediately. It needs to sit between 2°C and 8°C. For the precise storage window that applies to your pen (including how long it can be kept at room temperature after removal) the Mounjaro Patient Information Leaflet is your definitive reference, not a forum post or a social media video. If you'd like a fuller picture of how Mounjaro is delivered and what to expect throughout the process, our dedicated page covers it in detail.

If you're unsure about anything at all, our team is available seven days a week and can talk you through it.

What cold-chain failure actually means for your treatment

Tirzepatide arriving outside the cold chain is a genuine clinical issue, not a minor inconvenience. Exposure to temperatures above the recommended range can degrade the active medicine, meaning the pen may be less effective or behave unexpectedly. This is distinct from counterfeit risk, even a genuine pen from a legitimate pharmacy can be compromised if it's been left in a warm van for hours.

The question our prescribers hear fairly regularly is: "my pen arrived and it doesn't feel cold, can I still use it?" The honest answer is: check the leaflet's room-temperature guidance for the exact window, and if you're outside it, contact your pharmacy. Don't guess. If there's any doubt, the right decision is to request a replacement rather than proceed with a pen whose integrity is uncertain. You can read more about what to do in this situation on our page about Mounjaro arriving not cold, which goes into the specifics in detail.

Reputable pharmacies (including any GPhC-registered online pharmacy) take responsibility for the cold chain up to the point of delivery. If your pen arrived warm and the delivery was their dispatch, that conversation should be straightforward, and our page on receiving Mounjaro warm explains exactly what steps to take and when to request a replacement. Keep the packaging and take a photo before anything else.

Is the source legitimate? How to check before your first injection

The MHRA has confirmed that counterfeit tirzepatide pens have entered UK circulation, with approximately 20 million doses of illegally traded weight-loss medicines seized in 2025 alone at a street value of around £45 million. Fake pens have contained incorrect substances, causing real harm. This isn't scaremongering, it's the documented position of the UK medicines regulator.

The safest check you can do takes about 60 seconds. Visit the GPhC pharmacy register and search for the pharmacy that sent you your medicine. If it isn't listed as a registered premises, do not use the medicine. Legitimate pharmacies won't mind you checking, in fact, they'll expect it.

A second signal: did a prescriber actually review your case? A legitimate supply of tirzepatide requires a clinical consultation and a prescription issued by a qualified prescriber. If you ordered without completing a medical questionnaire, without any kind of consultation, or without receiving a prescription reference, that's a red flag regardless of what the packaging looks like. The MHRA's drug safety communications are clear that tirzepatide must only be supplied through the licensed prescription route.

At nume, every consultation is read by a GPhC-registered Independent Prescriber (a named clinician, not a automated system) before anything is dispatched. You can read about the clinical team behind that process on our clinical oversight page.

Clinical suitability, repeat orders, and what changes along the way

Getting a delivery is not the same as being on treatment indefinitely. Tirzepatide is licensed for weight management in adults with a BMI of 30 or above, or 27 or above alongside a weight-related health condition such as high blood pressure or type 2 diabetes, lower BMI thresholds apply for some ethnic backgrounds under NICE guidance. The NICE appraisal of tirzepatide (TA1026) sets out the full eligibility framework if you want to read the clinical detail.

What changes with each repeat is important too. A responsible pharmacy re-reviews your case before every subsequent order. Dose increases, in particular, should follow evidence of response and tolerability, not just the passage of time. If you've transferred from another provider, your new prescriber will want to see documentation of your current dose and how you've been getting on.

There are also situations that pause treatment: pregnancy, breastfeeding, and actively trying to conceive all mean tirzepatide is not appropriate, and you should discuss stopping with your prescriber rather than making that call alone. The same applies before any surgical procedure, your anaesthetist needs to know you're taking a GLP-1 medicine. Many patients also wonder whether they can drink alcohol while on treatment, and our page on drinking on Mounjaro covers the evidence and practical guidance in full. For context on how tirzepatide interacts with other areas of your health, our page covering tirzepatide and liver health and the cardiovascular considerations page both go into the evidence in depth.

If you're weighing up whether the delivery process and the treatment itself are right for you, the free consultation with our prescribers is the right starting point. There's no obligation, and the clinical review happens the same day for orders placed before noon.