Where in the arm do you inject Wegovy — and how to do it right

Imagine it's your first pen and you're standing in front of the bathroom mirror

The box arrived by DPD the previous morning in plain packaging, nothing on the outside to hint at what's inside. Now you're holding the Wegovy pen and wondering exactly where on your arm it goes, and if you can use your arm at all, a dedicated page answers whether you can inject Wegovy in your arm and covers the key considerations in detail. Find the midpoint between your shoulder and elbow on the outer side of the arm. That fleshy, accessible area is the lateral deltoid region, and it is the part the Wegovy SmPC designates as the upper-arm site. Avoid the front of the arm, the inner arm, and anything near the shoulder joint itself. You're looking for a site where you can press the pen flat without it resting on bone.

Before the pen touches skin, clean the site with an alcohol swab and let it air-dry for a few seconds. Press the pen firmly and squarely against the skin so the skin-contact window is fully covered, then hold it there and press the button. You'll hear a click. Hold for about ten seconds. A second click or a visible indicator confirms the dose is complete. The needle retracts automatically. For anyone still building confidence with arm self-injection, a broader guide to all three Wegovy injection sites walks through each one side by side.

One practical note from prescribers: if you have less subcutaneous tissue in the arm, the abdomen or thigh may deliver a more consistent injection. This is worth raising at your next clinical review.

Why rotating away from the arm each week matters

Using the same patch of skin week after week leads to a condition called lipohypertrophy — small, firm lumps of scar-like tissue that form under repeated injection sites. This isn't just uncomfortable; insulin and other subcutaneous medicines absorb less predictably through those lumps, and the same principle applies to semaglutide. Rotating between the upper arm, the abdomen, and the thigh each week (or moving to a different spot within the same area) keeps the tissue healthy and absorption consistent. The NHS medicines information for semaglutide specifically recommends rotating injection sites each week.

A practical system is to use the arm one week, the abdomen the next, and the thigh the week after, then repeat. Within each area, shift slightly, a few centimetres from last time. If you notice redness, swelling, or a hard lump at a previous site, skip that area until it settles. Mild skin reactions at the injection site are among the more commonly reported side effects of Wegovy; they usually resolve on their own. If a reaction is severe, persists beyond a few days, or comes with signs of an allergic response (such as a spreading rash or breathing difficulty) contact your prescriber or seek urgent medical attention. You can also report suspected side effects through the MHRA Yellow Card scheme.

For a closer look at using the thigh as an alternative, the leg injection guide covers the technique and positioning in the same level of detail.

Self-injection versus asking someone to help, does it change the arm site?

The site itself doesn't move depending on who injects. But the practicalities are different. Reaching the outer upper arm yourself means either using a mirror or developing a feel for the pen's position without direct line of sight. Some people find it completely manageable within a few weeks; others genuinely prefer the abdomen or thigh for solo injections because they can see what they're doing. Neither preference is wrong. If a partner, family member, or carer is administering the injection, the arm is often described as the most convenient site for the person giving it, since the arm can be held steady and the site is clearly visible.

Whatever the arrangement, the technique is identical: clean skin, press the pen flat against the outer mid-upper arm, activate, hold for ten seconds. One thing to avoid in the arm specifically is injecting into muscle rather than the subcutaneous fat layer just beneath the skin. Pressing too hard into a very lean arm can increase the risk of intramuscular injection, which can be more painful and change how the medicine is absorbed. If you're uncertain whether you have enough subcutaneous tissue at the arm site, discuss it with your prescriber. The arm injection overview also covers this question in more depth. As for the pen itself, it is designed to help: the needle length in the Wegovy pen is standardised to reach the subcutaneous layer across the range of body types for which it is licensed.

If you're considering starting Wegovy and want to understand the full picture (including how much it costs privately) the Wegovy pricing page gives an honest, transparent breakdown of what's included in a private prescription through a regulated UK pharmacy.