How to inject yourself with semaglutide: a step-by-step practical guide

The decision that trips most people up: where on your body to inject

Three sites are licensed and practised: the abdomen (at least 5 cm away from your navel), the front of your thigh, or the back of your upper arm. Each works well, and there is no clinical reason to prefer one over another. The practical difference is access. The abdomen is easiest to see and pinch; the thigh is next; the upper arm is manageable but usually easier if someone else can help, or if you practise the angle in a mirror first.

What matters more than which site you pick is rotating between them. Using the same small patch week after week can cause localised skin thickening (a condition called lipohypertrophy) which slows absorption. A simple rotation: abdomen one week, thigh the next. If you want a mapped-out schedule, our step-by-step guide to self-injecting semaglutide goes into site rotation in more detail. The NHS patient information for semaglutide also describes the licensed sites clearly and is worth reading alongside your pen's leaflet; you can find it on the NHS semaglutide medicines page.

Avoid injecting into skin that is bruised, red, scarred or affected by stretch marks. Clean the chosen spot with an alcohol swab and allow it to dry fully before the pen touches your skin, wet skin stings more, and residual alcohol can interfere marginally with absorption.

Preparing the pen: the three checks that prevent most errors

Take the pen out of the fridge roughly 30 minutes before you plan to inject. Cold medicine is more viscous and the injection feels sharper than it needs to. While it warms, run through three checks.

First, confirm the label: dose, name, expiry date. Especially at dose increases, make sure the pen in your hand is the strength your prescriber has moved you onto. Second, inspect the medicine window. Wegovy should be clear to almost colourless; if it looks cloudy, discoloured or contains particles, do not use it. Set it aside and contact your prescriber or pharmacist. Third, check the pen tip is sealed, the grey cap should be on and intact. Never attach the needle ahead of time if you are not about to inject; pre-attached needles introduce contamination risk and allow air to enter.

When you are ready, peel the foil from a new needle, screw or push it onto the pen tip firmly (depending on your pen version), and remove the outer needle cap. Keep the inner cap on until the moment of injection. For those who prefer to prepare everything in advance, pre-cut alcohol swabs make the site-clean step quick and consistent. Check your pen's Patient Information Leaflet for the exact priming steps, some Wegovy pen formats require a small air-shot before use, and the leaflet will tell you whether yours does.

The injection itself: what to do in the 10 seconds it takes

Pinch about 2–3 cm of skin and subcutaneous tissue between your thumb and forefinger, this lifts the fatty layer away from muscle. Hold the pen at a 90-degree angle to the skin surface. Press it firmly against the pinch, then press the injection button until you hear or feel a click. Keep the pen pressed against the skin for a slow count of ten. This pause matters: it allows the full dose to deposit before you remove the pen.

Release the pinch, remove the pen, then apply gentle pressure with a clean finger or cotton wool if there is a small bleed. Do not rub the site vigorously; rubbing disperses the medicine unevenly. The full injection technique guide covers each of these steps with additional detail, including what to do if the pen does not click, or if you are unsure a full dose was delivered.

Once used, the pen tip locks. Refit the outer needle cap (never the inner one, to reduce needlestick risk) and unscrew the needle for disposal. Used needles and pens go into a sharps container, not the household bin. A 1-litre sharps container sits neatly in a bathroom cabinet and meets NHS disposal standards.

After the injection: storage, missed doses and when to call for help

Remaining pens go back in the fridge (2–8°C). The Wegovy SmPC sets a limited window during which a pen may be kept at room temperature if needed (for example when travelling) but always follow the exact figures in your Patient Information Leaflet rather than a general rule. The semaglutide storage conditions page sets out what the guidelines say; if you are planning a trip, the guide to travelling with semaglutide covers cold-chain logistics for flights and hotels.

If you miss a dose and your next scheduled injection is more than 48 hours away, you can take it late. If the next dose is fewer than 48 hours away, skip the missed one and continue on your normal day. Never take two doses at once. Timing decisions should ultimately follow your prescriber's instruction and the Patient Information Leaflet.

Seek medical help promptly if you develop severe, persistent stomach pain that spreads to your back, the MHRA has highlighted acute pancreatitis as an infrequent but serious potential risk with GLP-1 medicines, and that symptom pattern warrants same-day clinical review. You can also report any suspected side effects directly at the MHRA Yellow Card scheme. For a broader picture of how Wegovy works and what to expect, the Wegovy overview is a good next step.

If you are not yet on treatment and are considering whether semaglutide is right for you, a real clinician (not a questionnaire) reviews every consultation at nume. Speak to our prescribers and get a same-day clinical assessment.