A Wegovy Tutorial: What Actually Happens When You Start

The biggest misconception: Wegovy is not a high-dose medicine from day one

The thing most people get wrong before they start is assuming the dose they have read about in trial headlines is the dose they will inject on week one. It is not. The first pen contains 0.25 mg of semaglutide per weekly dose. That figure is intentionally modest. Its job is to let your body adjust to the medicine, not to produce immediate weight loss. Nausea, the side effect most people worry about, is strongly linked to how quickly semaglutide reaches higher levels in the body. Starting low reduces that sharply.

After roughly four weeks on 0.25 mg, the prescriber typically moves the dose to 0.5 mg, then 1.0 mg, then 1.7 mg, and finally 2.4 mg, the licensed maintenance dose. Each step takes about a month. The whole titration typically spans four to five months. Some people stay longer at a lower step if they are managing side effects; that is a clinical decision, not a failure. If you are curious about the evidence base behind these doses, the STEP 1 trial that supported Wegovy's approval is worth reading.

So let the misconception go gently: slow is the point. The gradual increase is not a delay in your treatment starting, it is part of how the treatment works.

How to actually use the pen

Each Wegovy pen comes pre-filled and pre-set to the correct dose for that month. You do not draw up any medicine, turn any dial, or calculate anything. You attach a new needle, choose an injection site (the abdomen, outer thigh, or upper arm all work) clean the area, and press the pen against the skin until you hear or feel it click. Hold it in place for around ten seconds, then remove it.

Rotate the injection site each week. Using the same spot repeatedly can cause a lump of fatty tissue to form under the skin, which affects how the medicine is absorbed. Pick a different area of the same region, or cycle between the three sites across weeks. The needle is short and fine; most people find the injection itself unremarkable within a couple of attempts.

Store the pen in the fridge between 2°C and 8°C until you need it. Once a pen is in use, there is a limited window during which it can be kept at room temperature, the exact duration is in the Patient Information Leaflet that comes with your prescription, and that is the document to follow rather than any general advice you read online. The NHS semaglutide medicines page also covers storage in plain language.

Side effects to know about, and the one that matters most

The most common side effects are gastrointestinal: nausea, loose stools, constipation, indigestion, and sometimes burping. They follow a predictable pattern. They are at their worst in the first week or two after a dose increase, then typically settle as the body adjusts. Eating smaller portions, avoiding very fatty or rich food around injection day, and staying well hydrated all help. Fatigue and mild headache are also reported, particularly early on.

One side effect that needs immediate medical attention is severe stomach pain that spreads to the back, with or without vomiting. This can be a sign of pancreatitis, a serious but infrequent complication. The MHRA issued a Drug Safety Update on GLP-1 medicines in January 2026 drawing attention to this specifically, if that kind of pain develops, stop the injection and seek urgent help rather than waiting to see if it settles. You should also tell any clinician treating you that you take Wegovy, including before any surgical procedure.

If you want to go deeper on results rather than side effects, the clinical trial findings for Wegovy cover the weight-loss evidence in detail, and if you are interested in how the broader semaglutide trial research shaped what we know about this medicine, that page sets it out clearly. For the broader picture of weight-loss treatment options, the treatment overview is a reasonable starting point.

Getting started: the prescription step you cannot skip

Wegovy is a Prescription-Only Medicine. A prescriber has to assess whether it is suitable for you before a single pen can be dispensed. The licensed criteria cover adults with a BMI of 30 or above, or 27 to 29.9 alongside at least one weight-related condition such as high blood pressure, type 2 diabetes, high cholesterol, or obstructive sleep apnoea. Lower BMI thresholds apply for some ethnic backgrounds under UK guidance.

At nume, that assessment is done the same day by a GPhC-registered prescriber who reads your consultation personally. There is no algorithm making a clinical call on your behalf. If the consultation is completed before noon on a working day and the prescriber approves treatment, the pen is dispatched the same afternoon and arrives via tracked DPD delivery the next working day, in plain packaging. The cost of treatment is shown on the Wegovy cost page, and it covers the consultation, prescription, and delivery as one transparent price.

If you are ready to find out whether Wegovy is right for you, start your free consultation and a prescriber will review your details the same day. If you would prefer to be seen in person, our page on finding a Wegovy trial near me can help you locate options in your area.