How do you take Wegovy — and what do people get wrong first?

The biggest myth: you just jab it in and the rest takes care of itself

A lot of people start Wegovy expecting a passive process. The pen arrives, you use it once a week, and the medicine handles everything. That is partly true (the pen itself is genuinely straightforward) but the part people underestimate is the dose schedule. Wegovy does not begin at a therapeutic dose. The 0.25mg starting dose exists primarily to let your digestive system adjust; it is not the level that produces meaningful weight change. Skipping ahead, or expecting results at 0.25mg that only come later at 1.7mg or 2.4mg, leads to early disappointment or, if someone tries to self-escalate, early side effects. Your prescriber sets the pace for a reason.

The other thing worth saying plainly: the pen does not hurt the way people imagine. The needle is very fine, and most people describe the sensation as minimal. Hesitation before the first injection is almost universal, a question our prescribers hear most weeks is whether it will sting badly. For the majority, it does not.

If you are weighing up how Wegovy compares to other licensed options, the Wegovy overview page sets out the full picture, including eligibility and what clinical trials showed about average weight loss over 68 weeks.

How the injection actually works, step by step

Each Wegovy pen comes pre-filled and pre-set to your current dose. You do not dial a dose or draw up medicine. The broad sequence, as described in the Patient Information Leaflet, is: wash your hands; choose your injection site and clean the skin; remove the pen cap; press the pen against the skin; press and hold the injection button until the dose counter shows zero and you hear a click; keep the pen pressed for a further six seconds before removing it.

That six-second hold is the step people most commonly rush. Lifting the pen too quickly can mean part of the dose stays in the needle rather than entering the tissue. It takes discipline when the instinct is to pull away fast.

Rotate your injection site each week. Reusing exactly the same spot repeatedly can cause the skin to thicken, which reduces absorption. You can inject into the abdomen, outer thigh, or upper arm, and you can alternate between all three. Do not inject into broken, bruised, or irritated skin. More detail on the injection technique itself is available if you want a closer look at each step.

Storage matters too. Wegovy pens are kept in the fridge between 2°C and 8°C. Once in use, a pen can be kept at room temperature for a limited period, check the Patient Information Leaflet for the exact window, since it varies and is not something to guess at. Keep pens away from direct sunlight and never freeze them.

What happens if you miss a dose or need to change your day

Missing a dose occasionally does not require panic, but timing matters. The NHS semaglutide medicines page describes the general guidance: if you remember within five days of the missed dose, take it as soon as you can and then continue on your usual schedule. If more than five days have passed, skip that dose and wait until your next scheduled day. Never take two doses to make up for a missed one.

Changing your weekly injection day is possible if your usual day stops working for you, say, a Monday schedule that clashes with travel. As long as the gap between two consecutive doses is at least four days, you can shift the day. Your prescriber can confirm this during a review. If you are considering switching between Wegovy and another licensed medicine for weight management, that is also a conversation for your prescriber, not something to do unilaterally. Practical guidance on managing Wegovy injections week to week covers these scenarios in more detail.

A note on cost: people sometimes ask whether the titration schedule affects what they pay month to month. Wegovy pricing in the UK depends on the dose and provider; it is worth understanding what a legitimate private prescription includes before comparing headline figures.

Side effects to expect, and when to contact a doctor

The most common side effects of Wegovy are gastrointestinal: nausea, vomiting, diarrhoea, constipation, and indigestion are all reported frequently, particularly in the first weeks after starting or after a dose increase. For most people these settle as the body adjusts. Eating smaller portions, avoiding fatty or rich food, and keeping well hydrated all help. Fatigue and headache also appear in the early weeks for some people.

Less commonly, some people notice unusual symptoms that are harder to place. Sneezing and nasal symptoms have been reported during Wegovy treatment, while not a listed common side effect, it is not unheard of.

There are situations that need prompt medical attention rather than watchful waiting. Severe, persistent stomach pain that radiates toward the back (especially if accompanied by vomiting) should not be left until the next clinic appointment. The MHRA highlighted acute pancreatitis as a known, infrequent but serious risk associated with GLP-1 medicines; get urgent help if that symptom pattern appears. Signs of a serious allergic reaction, symptoms of gallbladder problems, or feelings of low mood or self-harm should all be assessed by a doctor without delay. Any suspected side effects can be reported through the MHRA Yellow Card scheme.

Wegovy is not licensed for use during pregnancy, breastfeeding, or in anyone trying to conceive, and it is not approved for under-18s. If your circumstances change in any of these respects, speak to your prescriber promptly.