How to Use a Semaglutide 5mg Pen: What to Do Before, During and After Your Injection

What should you check before you pick up the pen?

Start with the pen itself. Take it from the fridge and let it reach room temperature for about 30 minutes before injecting, cold semaglutide tends to sting more, and a warmer pen is easier to hold steady. While you wait, check the label: confirm it shows 5mg semaglutide and that the expiry date has not passed. Look through the viewing window at the liquid inside. It should be clear and colourless or faintly yellow with no visible particles. If it looks cloudy, discoloured or contains floating matter, do not use that pen and contact your prescriber.

Next, check that the dose counter on the pen reads a full dose and has not already been activated. Wash your hands thoroughly with soap and water. Gather what you need: the pen, an alcohol swab, and a sharps container for safe disposal. For a practical one-minute habit, count the remaining doses on your pen at the same time each week (right before you inject) so you always know when to request your next supply. The dosage details for the 5mg pen explain the wider clinical picture of where this strength sits in treatment.

The NHS semaglutide medicines page also provides a clear summary of injection preparation that is worth reading alongside your Patient Information Leaflet.

Where exactly do you inject, and how do you rotate sites correctly?

Three sites are licensed for Wegovy injections: the abdomen (at least five centimetres from the navel), the front or outer thigh, and the outer upper arm. Any of these is correct. What matters over time is that you do not reuse the same precise spot week after week. Repeated injections into identical tissue can cause lipohypertrophy, a fatty lump under the skin that can alter how the medicine is absorbed. A simple rotation pattern: abdomen one week, thigh the next, upper arm the week after, then start again, shifting a few centimetres within each area each time.

Clean the chosen site with an alcohol swab and let it dry fully before injecting, injecting through wet skin can sting. Remove the pen cap, press the pen flat and firmly against the skin at a 90-degree angle, then press and hold the injection button. You will hear or feel a click when the dose begins. Keep the pen pressed against the skin for the full six seconds after the click; removing it earlier risks losing part of the dose. Withdraw the pen and, if there is a small bleed, press gently with a clean swab. Do not rub the site.

If you want to understand how the full schedule of injection pens works together, the guide to using a Wegovy four-dose pen covers the mechanics shared across every pen format.

What are the most common injection-related problems and how do you manage them?

Redness, mild bruising or a small lump at the injection site are reported by some people, especially in the first weeks of treatment. These usually settle within a day or two. Consistent site rotation is the main preventive step. If a site becomes persistently sore, avoid it for several weeks and use one of the other approved areas instead.

Systemic side effects at the 5mg stage are typically gastrointestinal: nausea, loose stools, constipation or indigestion. These tend to peak in the first few days after a dose increase and ease as the body adjusts. Eating smaller meals and avoiding very fatty foods can help. Severe or persistent abdominal pain that radiates to the back is different, that warrants prompt medical assessment to rule out pancreatitis, which the MHRA flagged as a known risk in a 2026 Drug Safety Update for GLP-1 medicines. Any sign of an allergic reaction (swelling, difficulty breathing, rapid heartbeat) means stop the injection and seek immediate help.

If you miss a dose, check the Patient Information Leaflet for guidance on timing. Do not take two doses close together to make up for a missed one. Decisions about missing a dose, delaying a dose or changing your injection day all sit with your prescriber, not a general-purpose answer here.

How should the pen be stored, and what happens when a pen is used up?

Wegovy pens must be stored in a refrigerator between 2°C and 8°C, away from the freezer compartment and away from direct light. Do not store them in the fridge door where the temperature fluctuates each time it is opened, a shelf towards the back is better. Once you have started using a pen, the SmPC sets out a limited window during which it can remain at room temperature; refer to the Patient Information Leaflet or the eMC SmPC for that exact period, since it is product-specific and should not be paraphrased here.

When a pen is finished, place it directly into a sharps container rather than a household bin. Never recap a used pen needle. Once full, your pharmacist or GP surgery can advise on sharps collection in your area. The guide to semaglutide's loading dose puts the early weeks of treatment into context if you are still in the titration phase, and the Wegovy overview covers the broader treatment picture. For current treatment pricing, the Wegovy cost page sets out what the private prescription typically covers.

If you have questions about your technique or notice anything unexpected, our prescribers are available for aftercare seven days a week. Check your eligibility if you have not yet started treatment and want a same-day clinical review.