Are there any common mistakes people make when administering Wegovy?

Common slips include not rotating sites weekly, reusing needles, injecting before the pen returns to zero/indicator finish, or storing pens incorrectly (too warm/cold). Some people inject into muscle by pushing too hard or choosing very lean areas — aim for the fatty layer under the skin. Others mis-handle missed doses (doubling up) or rub the site afterwards, which can worsen irritation. A quick checklist — new needle, flat contact, full hold, safe disposal — prevents most problems.

The importance of site rotation

One of the most frequent mistakes with injectable medicines is neglecting to rotate injection sites. NICE guidance and NHS practice both stress that using the same area repeatedly can lead to lipohypertrophy, a thickening or lumpiness of the fatty layer under the skin. This can make injections more uncomfortable and reduce the predictability of absorption. With Wegovy, which is injected weekly into the abdomen, thigh, or upper arm, the advice is to move to a different spot at least a finger’s width or two away each week. Some patients have found it helpful to keep a simple log or phone note to track which site was used last. By rotating consistently, people can protect skin health and ensure the medicine continues to work as expected.

Needle use and injection technique

Another common mistake is reusing needles. Each injection should be with a new, sterile needle to prevent infection, avoid blunting, and ensure smooth delivery of the dose. NHS clinics stress this point in training sessions, as dull or contaminated needles can cause unnecessary pain and increase the risk of skin reactions. Technique also matters. Pressing the pen too hard into very lean areas can push the needle into muscle instead of the fatty layer, leading to discomfort or reduced effectiveness. Conversely, not pressing flat against the skin can mean incomplete delivery. Holding the pen in place until the indicator reaches zero is essential, as removing too soon can result in a partial dose. These details may sound small, but they are critical for the medicine to work properly week after week.

Storage errors and temperature sensitivity

Wegovy pens are sensitive to temperature changes. Before first use, they must be stored in the fridge between 2–8 °C, but never frozen. Once a pen is in use, it can usually be kept at room temperature below 30 °C for up to six weeks. A frequent mistake is leaving pens in hot cars, on windowsills, or near heaters, which can degrade semaglutide and reduce effectiveness. Others mistakenly place pens in the freezer, which makes them permanently unusable. NHS patient materials and MHRA guidance emphasise correct storage because stability studies show that temperature control is directly linked to safety and potency. Planning ahead — for example, using an insulated travel case when going out — helps avoid accidents. Some people mention that they feel more confident once they adopt the routine of checking pen storage regularly as part of their weekly preparation.

Mis-handling missed doses

When a dose is missed, the rules are simple: if you remember within five days, inject as soon as possible; if more than five days have passed, skip it and wait until your next scheduled dose. One of the most serious mistakes is doubling up on injections to “catch up.” This increases the risk of nausea, vomiting, dizziness, or dehydration, without improving weight-loss results. NHS guidance is clear that doubling doses is unsafe. The STEP trials demonstrated that consistent weekly dosing is what drives results, not short-term increases. Patients sometimes worry that a single missed dose will undo progress, but clinicians reassure them that long-term outcomes are unaffected as long as the overall schedule remains steady.

Aftercare and site irritation

Rubbing or massaging the injection site after dosing is another mistake people sometimes make. While it may seem like a way to ease soreness, in fact it can irritate the skin and worsen redness or swelling. NHS training usually advises applying a cool pack instead, if discomfort occurs. Wearing loose clothing around the area for a few hours afterwards also helps. It is also important not to leave needles attached to pens after injection, as this can allow air or bacteria to enter the cartridge, affecting safety. Safe disposal in a sharps bin prevents injuries to others. Pharmacies in the UK provide take-back schemes for full sharps containers, ensuring safe handling.

The main message

Most of the common mistakes with Wegovy injections are preventable with training and simple habits. Not rotating sites, reusing needles, removing the pen too soon, or mis-storing pens can all affect comfort, safety, or effectiveness. Mis-handling missed doses or rubbing the injection site afterwards can also cause unnecessary problems. NHS services provide checklists, helplines, and training to help people build confidence. The STEP and SELECT trials relied on strict adherence to good technique, and NICE guidance embeds this into everyday care. The main message is clear: with consistent attention to storage, technique, and follow-up, these mistakes can be avoided, and treatment can remain safe and effective.