The best places to inject Wegovy for weight loss — and how to rotate them

Picture this: your first pen has arrived, and you're looking at three possible spots

The plain, unbranded box from DPD turns up the morning after you ordered. Inside is the Wegovy KwikPen — a pre-filled, pre-set device that handles the dose for you. What it doesn't do is tell you exactly where on your body to put it. That part is down to technique.

The abdomen is where most people start, and for good reason. The belly has a relatively consistent layer of subcutaneous fat, it's easy to see what you're doing, and you can sit comfortably while you inject. Avoid the area within roughly 5 cm of your navel, the tissue there is denser and absorption is less predictable. Anywhere else on the lower or side abdomen is fair territory. Left one week, right the next, and a slightly different spot within each half each time.

The front and outer thigh is the second most popular choice. It works especially well for people who find the abdomen uncomfortable or who are wearing an insulin pump or sensor in that area. Use the fleshy outer area roughly halfway between the hip and the knee, not the inner thigh, where the skin is thinner and more sensitive. Some people find it easiest to inject the thigh while seated with the leg relaxed.

The upper outer arm is the third option. One practical note: most people need someone else to do this site for them, or at least to help position the pen, unless they are very flexible. If you live alone and the arm is your preference, it takes a bit of practice. The step-by-step guidance on taking Wegovy correctly covers technique tips worth reading before your first injection.

Why rotation matters more than people expect

Using the same spot every week causes a real problem: lipohypertrophy. That's the medical name for the fatty lumps that develop when the same patch of tissue is repeatedly punctured. The lumps look harmless but they slow absorption, which means your dose isn't working as reliably as it should. You might not notice it happening until the effect of the injection feels inconsistent.

A simple system beats willpower here. Some people write a small grid in a notebook: abdomen left, abdomen right, left thigh, right thigh, repeat. Others use a phone reminder. The NHS guidance on weight-management injections confirms the rotation principle as standard practice, and the Mounjaro SmPC carries an equivalent note for that medicine too, the principle holds across the class.

Within each site, move at least 1–2 cm from last week's spot. You're aiming for a cycle that takes several weeks before it returns to exactly the same square centimetre. Skin that's well-rotated stays supple and absorbs predictably throughout your treatment.

If you notice a hard lump, redness that isn't fading, or significant bruising at a site, flag it to your prescriber. It rarely turns out to be serious, but persistent skin reactions are worth documenting, they affect your rotation plan going forward.

Getting the technique right: pinch, angle, and what to do after

Subcutaneous injection goes into the fat layer just beneath the skin, not the muscle underneath. The pinch-lift technique helps: gently gather a fold of skin between thumb and forefinger, hold it lightly, and inject at the angle specified in your Patient Information Leaflet. For most pen designs that's a 90-degree angle held against the skin, but follow your leaflet exactly, because pen formats differ.

Wipe the chosen spot with an alcohol swab and let it dry for a few seconds before inserting the needle. Wet skin can sting more than necessary. After the injection, release the skin fold, hold the pen in place for the number of seconds your leaflet specifies (this varies by pen), then withdraw smoothly. Don't rub the site afterwards, rubbing can push the medicine into the wrong tissue layer.

Always use a fresh needle for each injection. Reused needles blunt quickly and increase both discomfort and infection risk. The Wegovy pen overview explains how the device is set up, which helps new starters understand the whole process before that first injection, and if you want to go deeper on placement, the guidance on finding the best place to inject for weight loss covers the reasoning behind each site in useful detail. Used needles go into an approved sharps container, the 1-litre sharps bin from our pharmacy is a practical option to have on hand from day one.

Storage matters too: the pen should be kept refrigerated until you need it, but the exact window you have at room temperature before using it is one to check in your leaflet rather than rely on general advice. If you are ever unsure how to store a pen that's been out of the fridge, the fridge storage guide explains the principles, though for the pre-filled Wegovy pen your PIL is the definitive source.

Reporting skin reactions and when to seek medical advice

Most site reactions are minor: a small red mark, mild itching, or a tiny bruise. These usually clear within a few days and are largely a rotation and technique issue rather than a sign of intolerance to semaglutide itself.

More significant reactions to watch for include persistent swelling, a hard nodule that isn't resolving, signs of infection (warmth, spreading redness, pus), or a generalised allergic response, hives, swelling of the face or throat, difficulty breathing. Any of those warrants prompt medical attention. The NHS semaglutide patient information page lists the side effects associated with this medicine, including the skin-related ones, in plain language.

Patients can report any suspected side effect to the MHRA directly via the Yellow Card scheme. It's worth knowing this exists, it's how the MHRA tracks real-world safety signals, and semaglutide is under additional post-market monitoring as a Black Triangle medicine.

If you're working out whether Wegovy is the right option for your situation, looking at the full Wegovy treatment overview gives a broader picture of how the medicine works, what the clinical evidence shows, and how a private prescription route compares to NHS access. Pricing context is covered on the Wegovy cost and pricing page for anyone weighing up the commitment involved. When you're ready to take the next step, checking your eligibility with our prescribers is the place to start.