What to Expect When You Begin a Wegovy Starter Dose

Why starting low is the right decision, not a delay

It can feel frustrating to begin on a dose that is openly described as a tolerability measure rather than a treatment dose. But there is solid reasoning behind it. GLP-1 medicines like semaglutide slow gastric emptying and reduce appetite through gut-hormone pathways, and introducing that effect gradually gives your digestive system the best chance of adjusting without serious discomfort.

The titration pathway for Wegovy runs: 0.25mg for four weeks, then 0.5mg, 1mg, 1.7mg, and finally 2.4mg as the maintenance dose, with roughly four weeks at each level. Your prescriber decides the pace; if a particular step causes significant side effects, they may recommend staying at that level for longer before moving up. This is not a setback. It reflects exactly the kind of clinical oversight the medicine requires.

The STEP 1 trial, published in the New England Journal of Medicine, followed 68 weeks of treatment and reported an average body-weight reduction of around 15% at the 2.4mg maintenance dose. Those results were built on the same careful titration schedule. Rushing the start does not improve the outcome; it typically just increases the chance of early side effects that lead people to stop.

If you want a fuller picture of what the titration journey involves practically, including what to have ready before your first injection, the Wegovy starter kit our site puts together covers the essentials alongside the practical guide to starting Wegovy, which walks through the process step by step.

The side effects most people notice in the first few weeks

Nausea is the side effect people mention most. It tends to arrive in the days following an injection, and for most people it fades within a week or two as their body settles. Other GI changes, including loose stools, constipation, indigestion and some burping, are also reported during the early phase. Fatigue and mild headaches appear occasionally. Injection-site reactions, such as brief redness or tenderness, are possible at the abdomen, thigh or upper arm, where the injection is given.

None of this is a reason to avoid treatment, but it is worth knowing about before you start. A few practical habits help most people through the early weeks: smaller portions, eating slowly, keeping well hydrated, and avoiding fatty or very rich food around injection day.

The NHS medicines page for semaglutide lists the full side-effect profile in plain English and is worth reading before your first dose. Keep it bookmarked.

Seek urgent medical attention if you develop severe, persistent stomach pain that radiates to your back, this can be a sign of pancreatitis, a known but infrequent risk with GLP-1 medicines that the MHRA has highlighted in its safety communications. Signs of a serious allergic reaction (swelling of the face or throat, difficulty breathing) also require immediate help.

Who the Wegovy starter schedule is and is not suited to

Wegovy is licensed for adults. It is not recommended during pregnancy, while breastfeeding, or if you are actively trying to conceive. It is not used in under-18s. People with a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia type 2, or with a history of pancreatitis, should discuss these points with a prescriber before starting.

The licensed eligibility threshold is a BMI of 30 or above, or 27 or above alongside at least one weight-related condition such as high blood pressure, high cholesterol, obstructive sleep apnoea or type 2 diabetes. For some ethnic backgrounds, UK guidance applies thresholds that are 2.5 kg/m² lower. BMI alone is not the whole picture; a prescriber weighs your full medical history, current medicines and individual circumstances. You can check your BMI as a starting point using the NHS BMI calculator.

Women taking oral contraceptives should be aware that tirzepatide (Mounjaro) specifically can reduce pill absorption during the early weeks of treatment. The current evidence does not indicate the same interaction with semaglutide, but discuss your contraception with your prescriber as part of your consultation. If you are unsure whether Wegovy or another licensed option suits you better, our semaglutide overview and the weight-loss treatments page set out the options available through nume.

Cost, equipment, and what else you might need to know before ordering

Wegovy is a private prescription medicine through services like ours. Prices in the UK vary by dose and provider, but you should expect any legitimate quote to include the prescription and clinical assessment alongside the medicine itself. For a clear comparison of what private treatment costs across the market, our Wegovy price comparison page explains what to look for and what headline figures often leave out.

On a practical note: your pen will need to stay in the fridge between 2°C and 8°C. Room-temperature storage is permitted for a limited window, your Patient Information Leaflet gives the exact timeframe, and it is always the authoritative reference for storage and handling questions. The pen is pre-filled and pre-set, so no drawing up or measuring is required.

If you are wondering about anything else before you begin, our getting-started guide covers common practical questions, and our FAQs address the questions our prescribers hear most often. When you are ready, you can start your free consultation with one of our GPhC-registered prescribers, who will review your details the same day.