How to Open and Prepare a Wegovy Pen Correctly

What the official guidance actually says about preparing the pen

The semaglutide Patient Information Leaflet, published on the electronic Medicines Compendium, describes the Wegovy pen as a multi-dose device: each pen holds four weekly injections, dispensed through a click-dial mechanism. The starting point the leaflet emphasises is inspecting the medicine before you do anything else. Hold the pen so the medicine window faces you. The liquid should be clear and colourless to slightly yellow; if it looks cloudy, has visible particles, or is a different colour, do not use that pen and contact your prescriber or pharmacist.

The full injection technique covers site selection and the actual injection in detail, but the opening sequence specifically works like this. Pull the base cap straight off, it does not twist, it pulls. Some people find it stiff on a brand-new pen, which is normal. Under the cap you will see the needle attachment port. Take a new needle from its outer wrapper, then its inner wrapper, line it up straight, and turn it clockwise until it feels snug. Do not attach the needle until you are ready to inject; leaving it attached between doses increases the risk of blocked needles and air entering the pen.

The NHS medicines page for semaglutide also notes that you should check the expiry date on the pen label before use and confirm you have the correct dose setting for where you are in your titration schedule.

The part of opening the pen that causes the most confusion

A question our prescribers hear most weeks is whether the outer cap and the inner needle cap are the same thing. They are not, and mixing them up is the most common source of confusion when opening the pen for the first time.

The base cap is the large plastic cap that covers the entire tip of the pen body. It is what you remove to access the needle port. The needle itself arrives with two of its own protective caps: a larger outer needle shield and a smaller inner needle cap that sits closest to the tip. Once you have screwed the needle onto the pen, you remove the outer needle shield (keep it for safe recapping later), then the inner needle cap, and you are ready to inject. Discarding the inner needle cap accidentally is the one step that forces people to start over with a new needle.

If you are still building confidence with the device, the dose window and measurement markings on the pen body can help you confirm you have the right injection queued before you remove any cap at all. Checking the number showing in the window against your prescriber's instructions adds one extra verification step that costs nothing and prevents errors.

Storing the pen before and after you open it

How you open the pen is linked directly to how you have been storing it. Wegovy pens are refrigerated at 2–8°C before first use. A pen that has been left out too long or frozen may look normal but could have degraded medicine inside, which is why the visual check in the medicine window matters. After a pen is in use, storage requirements change, for the exact room-temperature window and the maximum time a pen can be kept outside the fridge, refer to the post-opening storage guidance, which reflects the current SmPC, rather than any figure we quote here.

One practical note: if you have taken the pen out of the fridge and it feels cold, letting it sit at room temperature for a few minutes before injecting can reduce injection-site discomfort. The NHS semaglutide guidance and the SmPC both permit this, provided the pen is back in use within the permitted time window.

After your injection, replace the outer needle shield, then unscrew the used needle and dispose of it in a dedicated sharps container. Replace the base cap on the pen body and return it to the fridge. Each pen lasts four weeks once it is in use, assuming one injection per week as prescribed.

Getting started on Wegovy through a regulated service

If you are considering semaglutide for weight management and want to understand the full picture before committing, the Wegovy treatment overview covers the evidence, eligibility criteria and what the titration schedule looks like from week one. For those weighing up the financial side, cost context for Wegovy sets out what a legitimate private prescription actually includes.

Wegovy is a prescription-only medicine. In the UK, the legal route is a clinical assessment by a qualified prescriber who decides whether it is appropriate for you. At nume, every consultation is read the same day by a GPhC-registered Independent Prescriber. If you are approved, treatment is dispatched the same day (orders placed before 12pm, Monday to Friday) and delivered free the next working day by DPD, in plain packaging. There are no subscriptions; every repeat order goes back through clinical review. If you are ready to take that first step, start your free consultation and our prescribers will take it from there.