Wegovy shots: what they are, how they work, and what to expect

Step 1, getting a prescription: the only legal starting point

You cannot legally obtain Wegovy shots in the UK without a prescription following a proper clinical assessment. That's not a technicality; it's the architecture of how these medicines are regulated. The NHS medicines page for semaglutide sets out the licensed indication clearly: weight management alongside a reduced-calorie diet and increased physical activity, for adults who meet the BMI threshold and have no contraindications.

In practice, a legitimate prescription route involves a consultation where a clinician reviews your BMI, your medical history, any medicines you already take, and conditions that might make semaglutide unsuitable. At nume, that consultation is free and reviewed the same working day by a GPhC-registered Independent Prescriber, a real clinician reading your answers, not automated screening software. Photo-ID verification and live weight confirmation happen before treatment is issued.

If you're thinking of transferring from another provider, evidence of your current dose and how long you've been on it will be needed before a prescriber can continue your treatment safely. It's a step worth expecting, not resisting.

Step 2, the titration schedule: why Wegovy shots start low

One thing that surprises people is how modest the first Wegovy shot feels. The 0.25mg starting dose isn't where the medicine does its main work; its job is to let your digestive system adjust before the dose climbs. Nausea is the most reliably reported side effect of GLP-1 injections, and beginning slowly is the mechanism that keeps it manageable for most people.

The standard schedule moves in roughly four-week steps: 0.25mg, then 0.5mg, then 1.0mg, then 1.7mg, reaching 2.4mg as the standard maintenance dose. The MHRA approved a higher 7.2mg maintenance dose in January 2026, initially supplied as three 2.4mg pens weekly, and a dedicated single-dose 7.2mg pen was approved on 14 April 2026, designed with a built-in covered needle that locks after use. Whether the 7.2mg dose is appropriate is a clinical decision; if you're curious whether it might apply to you, that's exactly the kind of question to raise at your Wegovy consultation.

Your prescriber sets the pace of titration. If a particular step causes significant side effects, it's normal to stay at the current dose a little longer before moving up. Never adjust the schedule without speaking to a clinician.

Step 3 (giving the shot: practical technique and what to check beforehand

Wegovy is injected subcutaneously) into fatty tissue just beneath the skin, at the abdomen, thigh or upper arm. You rotate sites to avoid soreness building at one spot. The pen is pre-filled and pre-set, so there's no drawing-up of fluid or manual dose adjustment involved.

One practical habit worth forming: before each injection, hold the pen up to the light and check that the liquid is clear and colourless. Cloudy, discoloured or particle-containing liquid is a signal to contact your pharmacy before using it. Takes about ten seconds and costs nothing.

Storage matters. Wegovy pens must be kept refrigerated at 2–8°C. If a pen has been out of the fridge, the exact window during which it remains usable is set out in the Patient Information Leaflet, always check the leaflet rather than relying on a figure quoted online, including here, because this is an area where the official document is the authority. For detail on how to administer Wegovy shots correctly, including site rotation and pen handling, we cover the technique in full on a dedicated page.

Side effects worth knowing about before you start

Most side effects from Wegovy shots are gastrointestinal and follow a pattern: more noticeable in the early weeks and after each dose increase, then settling as the body acclimates. Nausea, loose stools, constipation, reflux and fatigue are the commonly reported ones. They're real, but for most people they're manageable rather than a reason to stop.

A less common but more serious risk is acute pancreatitis. In January 2026 the MHRA issued a Drug Safety Update for GLP-1 medicines highlighting this: severe, persistent stomach pain that may spread to the back (with or without vomiting) warrants urgent medical attention, not a wait-and-see approach. You can read the full MHRA communications and report any suspected side effect through the Yellow Card scheme.

Wegovy shots are not recommended during pregnancy, while breastfeeding, or if you're actively trying to conceive. They're not licensed for anyone under 18. If you take oral contraceptives, it's worth discussing contraception with your prescriber before starting, as absorption may be affected. For a fuller picture of the side effects and safety profile of Wegovy, including what to monitor week by week, there's more detail in the dedicated guide.

If you'd like to understand how the cost of private treatment stacks up before you decide, the Wegovy price comparison page breaks down what's typically included (and what's often left out) across different providers.

When you're ready to see whether semaglutide shots are clinically suitable for you, check your eligibility with a free consultation, reviewed the same day by one of our prescribers. If you'd also like to explore in-person options, our guide to finding semaglutide shots near me can help you understand what to look for in a local provider.