Injecting Wegovy in the Stomach: What the Evidence Says About Site, Technique and Results

What the STEP trials established about abdominal injection

The STEP 1 trial (published in the New England Journal of Medicine) randomised nearly 2,000 adults with obesity to 2.4mg semaglutide or placebo over 68 weeks, with participants self-injecting weekly into the abdomen, thigh or upper arm. Average weight reduction in the semaglutide group reached around 15% of body weight. That result was not attributed to any single injection site: all three were treated as equivalent. What the trial did reinforce is that consistent weekly dosing, correct technique and rotating the injection point each week are the practical variables that matter. The Wegovy SmPC (available on the Electronic Medicines Compendium) formalises this: subcutaneous injection into any of the three sites is licenced, and patients should change the exact location within a site each time.

The stomach is popular for a practical reason: most people can pinch up an inch of subcutaneous tissue there without difficulty, which is what the technique requires. Upper arm self-injection is harder to perform without assistance; the thigh works well but can feel firmer. Neither is medically superior to the abdomen, but the abdomen's accessibility makes it the default for most self-injecting patients.

Finding the right spot on your stomach and rotating it properly

The licensed injection zone on the stomach is the lower abdomen, roughly the area between the hip bones, staying at least 2–3 cm away from the navel. Injecting too close to the navel can be more painful and may affect absorption. The area around a scar, broken skin or any area that is tender, bruised or hardened from previous injections should be avoided each week.

Rotation matters more than most people expect. Injecting repeatedly into the same small patch of skin can cause lipodystrophy, localised lumps or indentations in the fatty tissue that alter how the medicine is absorbed. A simple way to keep track is to move clockwise around the injection zone: left side of the stomach one week, right side the next, working slightly above or below the previous spot. Our guide to exactly where on the stomach to inject Wegovy covers this rotation pattern in more detail, with diagrams of the recommended zone.

Skin should be clean and dry before you inject. An alcohol swab can be used to clean the area, let it dry fully before injecting, since alcohol on the skin can cause a brief stinging sensation when the needle goes in.

Step-by-step: how the injection itself works

The Wegovy pen is pre-filled and pre-set to your current dose; there is no need to dial a number or attach a separate needle for most pen formats. Here is the general sequence, consistent with NHS and SmPC guidance, your own Patient Information Leaflet takes precedence for your specific device.

First, take the pen from the fridge and let it come to room temperature for around 30 minutes. Cold medicine can be more uncomfortable going in. Check the pen window to confirm the liquid is clear and colourless. Remove the pen cap. Pinch up a fold of skin at the chosen stomach site. Place the pen flat against the skin at a 90-degree angle, press firmly down, and activate the injection button. Hold the pen in place (most people count slowly to ten) before removing it. You should hear or feel a click when the dose has been delivered. If you would like more detail on the abdominal approach specifically, our page on how to inject Wegovy in the stomach walks through each consideration for that site. For a visual walkthrough of the technique, this step-by-step video guide runs through each stage of the process.

Used pens contain a retracted needle and must be disposed of in a sharps container, not in household waste. Most community pharmacies will accept sealed sharps containers for disposal.

Side effects to expect and when to get medical help

The most common side effects after injecting Wegovy are gastrointestinal: nausea, diarrhoea, constipation, reflux and burping. These are typically most noticeable after starting or stepping up to a new dose, and they tend to ease within one to two weeks as the body adjusts. Injection-site reactions (brief redness, itching or a small lump) are also common and usually settle quickly, particularly with good rotation practice. If you are taking the unbranded form of the medicine, our guidance on how to give a semaglutide injection in the stomach covers the same principles with wording that reflects the generic product.

Seek medical help promptly if you develop severe stomach pain that spreads to your back, with or without vomiting. The MHRA issued a Drug Safety Update in January 2026 flagging acute pancreatitis as a known, though infrequent, side effect of GLP-1 medicines that warrants urgent attention. You can report any suspected side effect through the MHRA Yellow Card scheme. Other signs that need prompt review include symptoms of a serious allergic reaction, signs of dehydration from severe vomiting or diarrhoea, or any symptoms you are uncertain about. If in doubt, contact your prescriber or call 111, our support team is also available seven days a week for aftercare queries. On the subject of cost or switching provider, a plain overview of where Wegovy is available in the UK covers the private and NHS routes without the sales pressure.