Wegovy 2.5mg: understanding the starter dose and what comes next

Why the schedule opens at 2.5mg rather than a higher dose

Semaglutide slows the rate at which the stomach empties and acts on appetite centres in the brain. Those effects are valuable for weight management, but introduced too quickly they can cause significant nausea and vomiting that make treatment very difficult to sustain. If you want to understand exactly what the opening strength involves, our page on 2.5mg semaglutide explains how this dose is calibrated to begin the process gently.

A question our prescribers hear most weeks is whether someone can skip straight to a higher dose to see results faster. The honest answer is no, and not because of an arbitrary rule. Starting at a lower strength gives the gut time to adapt to the slower gastric emptying; people who push through that adjustment period without it tend to drop out of treatment earlier. The starter dose is doing real work, just not the work most people expect.

After four weeks at 2.5mg, the schedule typically moves to 0.5mg, a point worth pausing on, because the numbering can look confusing. The Wegovy titration uses milligrams across a range that includes both sub-1mg and higher values; the full picture is covered in the guide to Wegovy's complete dosing schedule, which maps each step and what to expect at each stage.

The NHS medicines page for semaglutide provides a patient-level overview of how the medicine works and what the titration involves, and is a reliable starting point for anyone new to the treatment.

What to expect during the first four weeks on Wegovy

The first pen covers four weekly doses at 2.5mg. For many people this period passes with mild or no side effects; for others, the GI disruption is noticeable from the first injection. Both experiences are within the normal range. Common effects in the early weeks include nausea (particularly in the hours after injecting), looser stools, a feeling of fullness after small amounts of food, and occasional headache or fatigue.

These effects are not a sign that Wegovy is wrong for you. They tend to peak in the first one to two weeks at a new dose and settle as the body adjusts. The clinical evidence from the STEP 1 trial, published in the New England Journal of Medicine, followed participants over 68 weeks; most people who experienced early GI symptoms found them manageable enough to continue.

Injection technique matters too. Rotating between the abdomen, thigh and upper arm reduces injection-site reactions, and injecting at the same time each week (give or take a day) keeps things predictable. The Patient Information Leaflet inside the packaging carries the full guidance on this, read it before your first dose.

If symptoms feel severe or you are struggling to keep food or fluids down, contact your prescriber rather than stopping or adjusting doses on your own. Dehydration from persistent vomiting needs prompt attention. The Wegovy overview page covers the side effect profile in more detail alongside how to get support.

The decision about whether to stay at 2.5mg or move on

Most people move to the next step after four weeks. That decision sits with your prescriber, not with the schedule alone. If tolerability has been poor (significant nausea, repeated vomiting, or a difficult few weeks generally) it is legitimate and clinically sensible to stay at 2.5mg for a further four weeks before stepping up. The goal is sustainable treatment, not hitting a target date.

What is not advised is staying at 2.5mg indefinitely under the impression that this is a long-term maintenance dose. It is not licensed as one. The therapeutic benefit in the clinical evidence sits at maintenance doses, and the titration exists to get you there safely. For those further into the schedule, our pages on Wegovy 1.5mg and Wegovy 5mg cover what to expect at those later stages.

Thinking about the cost of each step as you work through the schedule? The Wegovy pricing page sets out what treatment involves at each stage, without hidden fees. At nume, one transparent price covers consultation, prescription and free next-working-day delivery, no subscription, no auto-renewals, and a prescriber reviews every repeat order before it is dispatched.

For anyone exploring whether Wegovy or tirzepatide (Mounjaro) might suit them better, that is a clinical conversation worth having. Our treatment overview covers both options side by side.

Who can be prescribed Wegovy, and how the assessment works

Wegovy is licensed for adults with a BMI of 30 or above, or a BMI of 27 or above alongside at least one weight-related condition such as high blood pressure, type 2 diabetes or obstructive sleep apnoea. Lower BMI thresholds may apply for some ethnic backgrounds under UK guidance.

BMI alone is not the whole picture. The prescriber's assessment looks at your medical history, current medicines, and any conditions that would change the risk-benefit balance. Wegovy is not recommended during pregnancy, while breastfeeding, or when actively trying to conceive. It is not licensed for people under 18. Some conditions (including a personal or family history of certain thyroid cancers, or a history of pancreatitis) require careful prescriber discussion before treatment starts.

At nume, every consultation is reviewed personally by a GPhC-registered Independent Prescriber. Your answers are not processed by an algorithm; a clinician reads them the same day. If you order before noon on a working day and your consultation is approved, your treatment is dispatched that afternoon and delivered free the next working day by DPD, in plain packaging.

You can verify any online pharmacy's registration on the GPhC register, it takes under a minute and is the clearest check you can make. Our own registration number is 9012878. If you're ready to find out whether Wegovy is clinically suitable for you, check your eligibility with a free consultation.