How do I use Wegovy, and what should I know before I start?

Choosing your injection day and keeping it consistent

The most important habit with Wegovy is picking a day you can stick to. Once a week, on a reasonably fixed schedule, is what the licensed guidance requires. If you miss your usual day, the Patient Information Leaflet sets out exactly what to do, and that document, specific to your pen, is the right place to look rather than general advice online. Your prescriber can also walk you through it.

Many people anchor the injection to something that already happens that day: the end of a gym session, a Sunday evening wind-down, or a weekday morning before work. The specific day matters less than the regularity. If you're thinking about how often Wegovy should be used and what counts as 'once a week', that page goes into more detail.

One thing worth knowing early: semaglutide affects how quickly your stomach empties, so the timing of meals around your injection day can influence how noticeable any nausea feels in the first weeks. If you want a fuller picture of how you use Wegovy for weight loss, including what to expect at each stage of the titration process, that page brings it together clearly. You don't change the dose yourself, that conversation happens with your prescriber at each review stage.

The injection itself: sites, rotation and technique

Wegovy is injected into the fat layer just beneath the skin (subcutaneously) at one of three sites: the abdomen (avoiding the two-inch ring around the navel), the front or outer thigh, or the upper arm. Rotating between sites at each injection reduces the chance of skin irritation building up in one spot.

The pen is pre-filled and pre-set. You don't draw up a dose or dial anything. Remove the cap, place the pen flat against clean skin, press the button until you hear a click, and hold it in place for a few seconds. Full technique steps are in the leaflet that comes with your pen, follow those, because pen design can vary between dose strengths. If you want a plain-language walkthrough of how to take Wegovy, covering each step of the process, that page is a practical reference alongside the leaflet. How to take Wegovy step by step covers the injection mechanics in more detail if this is your first time with a subcutaneous pen.

Some people feel nervous about self-injection before they try it. The covered-needle design and the auto-injector mechanism on the Wegovy pen mean you don't see the needle going in. Most people find it much less daunting than they expected after the first use.

Storage, refrigeration and what to do when you travel

Wegovy pens need to live in the fridge (between 2°C and 8°C) until you use them. The back of the fridge door is fine. They must be kept away from the freezer compartment, because freezing damages the medicine and means you should not use it.

There is a limited window during which a pen can be kept at room temperature once removed from the fridge, but that window depends on the specific product and your storage conditions. The Patient Information Leaflet for your pen states it precisely. Don't rely on a figure from a different country's guidance or a different product's leaflet, the eMC (the Electronic Medicines Compendium) holds the UK-authorised SmPC for Wegovy and is the authoritative reference.

Travelling with Wegovy is manageable with a little planning, an insulated cool pouch keeps the pen at a safe temperature during a day out or a flight. Declare it at airport security with any documentation your prescriber provides. If you're uncertain about storage on a longer trip, ask your clinical team before you go rather than after.

Side effects to watch for when you start

The most common effects when starting or moving up a dose are gastrointestinal: nausea, loose stools, constipation and indigestion. These are most noticeable in the first week or two at each dose level and tend to ease as your body adjusts. Eating smaller portions, avoiding very fatty foods and staying well hydrated all help.

Seek urgent medical attention for severe, persistent stomach pain that spreads toward the back. This is a symptom the MHRA flagged in its 2026 Drug Safety Update on GLP-1 medicines, it can indicate pancreatitis, which is an infrequent but serious condition. You can report any suspected side effect directly at the MHRA's Yellow Card scheme.

For a broader look at how semaglutide works and what the clinical evidence behind it covers, that page is a good companion to this one. And if questions come up about unexpected symptoms like sneezing while using Wegovy, we've covered those too. When you're ready to talk to a prescriber about whether Wegovy is right for you, starting a free consultation is the straightforward next step, our prescribers review every case personally, the same day.