What a Wegovy pen looks like after injection — and what to check

Step 1, What you see before you press (a quick baseline)

Before injection the Wegovy pen's viewing window is clear or shows the medicine itself, which is a colourless to slightly yellow liquid. The dose counter on the barrel shows the number of doses remaining. The needle is fully enclosed behind the cap, and nothing protrudes. It is worth taking a second to look at the liquid before every injection: discard the pen if you see particles, cloudiness beyond a faint tint, or any colour deeper than pale straw, and contact your prescriber. The full guide to how a Wegovy pen looks before use covers these checks in detail.

Storage matters here too. Wegovy must be kept refrigerated at 2–8°C; if a pen has been left out at room temperature, check the Patient Information Leaflet for exactly how long it remains usable, that window is product-specific and the leaflet is the definitive word, not a general estimate.

Step 2 (During the injection: what normal looks and feels like

Press the pen firmly against the injection site (abdomen, thigh, or upper arm) rotated each week) and hold down the injection button. You will hear or feel a click when the injection starts. The plunger moves slowly; some people feel mild pressure or a brief sting, which is entirely normal. Hold the pen in place for at least six seconds after pressing, this is the step most often rushed, and lifting too early is one of the few ways a partial dose genuinely occurs.

If you are unsure what the needle itself looks like or how deep it should sit, this page on the Wegovy needle explains the gauge and length clearly. The needle is fine and short by design, which keeps discomfort low for most people.

Step 3, What the pen looks like immediately after a successful injection

Lift the pen away from your skin and the first thing you notice is that the viewing window has turned yellow. This is the built-in dose-confirmation indicator: it means the needle has retracted into the pen body and the dose counter has advanced. The pen will not allow a second press, it locks after each dose. That lock is a safety feature, not a malfunction.

You may see a small bead of liquid on the skin surface where the needle was. This alarms people more than it should. The NHS patient information for semaglutide confirms that a tiny droplet at the injection site is common and does not mean the dose leaked out, the medicine has already passed into the subcutaneous tissue, which absorbs it over time. Blot gently; do not rub. If you want to understand what happens in your body after the first injection, that piece covers the absorption timeline.

One thing that does warrant attention: if the window did not turn yellow after a full, unhurried press, or if liquid visibly ran down your skin in a larger stream, contact your prescriber before taking another dose. Do not inject a second pen on the same day.

When the pen is empty: what a finished Wegovy pen looks like

Each Wegovy pen contains four weekly doses. When all four are used the dose counter reads zero, the viewing window remains yellow, and the plunger mechanism is fully depressed. The pen is now spent and locked permanently. Curious what that looks like visually? This page on an empty Wegovy pen goes through it photo-by-photo in description so you know exactly what finished looks like versus a pen that still has doses remaining.

Dispose of spent pens safely, a lidded sharps bin, not a household bin or recycling. Your local pharmacy or GP surgery can advise on collection points. The NHS guidance on semaglutide (Wegovy) on the NHS medicines pages also covers disposal briefly under the practical use section.

If you are planning ahead and wondering how quickly Wegovy starts to take effect after each injection, here is what the evidence says about onset and timing. And if you are still deciding between injectable and oral options, the weight-loss treatment overview sets out what is licensed in the UK and how the routes compare. For a sense of what treatment costs privately, our Wegovy cost page covers the pricing landscape honestly.

Starting Wegovy involves more than technique, a prescriber reviews your health picture, medications and goals before any treatment begins. When you are ready to take that step, speak to our prescribers through a free consultation, reviewed the same day by a GPhC-registered clinician.