How long a Wegovy pen lasts — and what to do with each one

You're holding the pen and wondering if you've missed your day

It happens to almost everyone on weekly injectables at some point. You know your injection day is Thursday, but it's now Saturday morning and the pen is still in the fridge. The short answer: if fewer than five days have passed since your scheduled dose, you can inject as soon as you remember and reset your next injection day from there. If it has been five days or more, skip that dose and wait for your next scheduled week. Never use two pens in the same week to catch up.

That guidance comes directly from the Wegovy prescribing information; for the precise wording, the Wegovy Summary of Product Characteristics on the eMC is the authoritative source. Your prescriber at nume will also have covered this during your clinical review, if you are ever unsure, the safest move is to contact your clinical team before injecting rather than guessing.

It is worth understanding what "one pen" actually means physically, and our guide on how long one Wegovy pen lasts walks through the practicalities in plain terms. Wegovy comes as a pre-filled, single-use pen. There is no dial, no refill, no cartridge to swap. You inject once, the device locks, and the used pen goes straight into a sharps container for safe disposal. Nothing carries over to the following week.

How the titration schedule affects how many pens you go through

Wegovy is not a one-strength treatment. The licensed UK schedule starts at 0.25 mg and steps upward (0.5 mg, 1.0 mg, 1.7 mg) before reaching the 2.4 mg maintenance dose, with roughly four weeks at each level. That means the pens in your first month's supply are a different strength from the ones you will use four months in. You can read a full breakdown of how the injection programme is structured on the Wegovy treatment page.

Practically, this matters for planning. If you are wondering how long a single pen lasts in terms of calendar time, the answer is always one week, but the pen you are on at week four looks nothing like the pen at week sixteen. Novo Nordisk supplies each dose level in its own pen format, so you are not splitting or measuring anything yourself.

The newer 7.2 mg single-dose pen, approved by the MHRA in April 2026, follows the same principle: one pen, one injection, one week. Reaching that dose still requires titrating through the earlier levels first, under prescriber supervision. Specific availability of any dose format is confirmed at the point of consultation, no provider should guarantee stock in advance.

Storage is where most people lose track of their supply

The cold-chain rules for Wegovy are tight, and they directly affect how usable a pen remains. Stored correctly in the fridge at 2–8 °C, a pen can be kept until the expiry date printed on the label. Once you take it out, you have a limited window at room temperature before it should be discarded, and if you want to know exactly how long 1 pen of Wegovy lasts once removed from the fridge, the answer depends on your specific dose strength, so check your Patient Information Leaflet rather than relying on memory.

A few things break the cold chain more often than people expect: leaving a pen in a hot car, packing it in hold luggage on a flight, or simply forgetting to return it to the fridge after checking the dose. If a pen has been outside the recommended temperature range and you are not sure it is still safe to use, the right call is to contact your prescriber or our aftercare team rather than risk an ineffective injection.

The NHS semaglutide medicines page has plain-English storage guidance, and our prescribers are available seven days a week for exactly these questions. A pen that has been temperature-compromised is not just potentially less effective, it represents a week's treatment, so it is worth the two-minute check.

What affects how long your overall Wegovy course lasts

The clinical trial evidence underpinning Wegovy's UK licence involved 68-week programmes; NICE's recommendation for semaglutide (Wegovy) under TA875 specifies a maximum treatment duration of two years within a specialist weight management service on the NHS. In private practice, duration is a clinical decision made between you and your prescriber, reviewed regularly.

People often ask whether they can pause treatment, for surgery, for pregnancy planning, or simply because supply was interrupted, and understanding how long Wegovy pens last in storage can help you plan around those interruptions sensibly. Each situation is different. For surgery specifically, the NHS advises telling your anaesthetist and surgical team that you are taking a GLP-1 medicine well in advance. For anything affecting when you next inject, a conversation with your prescriber is the right first step rather than stopping and restarting without guidance.

If cost is part of your thinking, the Wegovy pricing page sets out what private treatment involves and what is included. The more useful question for most people is whether a clinically supervised course that is reviewed before every repeat is the right fit for them. That assessment starts with a free consultation, details are on our treatment page.