The semaglutide starting dose, and what the evidence says about why it matters

Why the trial evidence shaped a cautious starting point

The STEP 1 trial enrolled 1,961 adults with obesity or excess weight and at least one weight-related condition, all without type 2 diabetes. Participants began on 0.25 mg weekly and moved through the titration ladder over roughly 16 weeks before reaching the 2.4 mg maintenance dose. By the end of 68 weeks, the average weight reduction was around 15% of body weight among those receiving semaglutide, a result that informed NICE's recommendation of Wegovy (TA875) and underpins the licensed schedule in use today.

The 0.25 mg figure was not chosen arbitrarily. Semaglutide slows gastric emptying and acts on appetite centres in the brain, and introducing it gradually gives the gut time to adapt. Starting higher produced more nausea in earlier trials without meaningfully improving early weight loss. That finding is now baked into the approved schedule: you begin low, your prescriber advances the dose in four-weekly steps, and the therapeutic effect builds as the dose rises. If you want to understand exactly what to expect from that first injection, our guide to the Wegovy starting dose explains the reasoning behind 0.25 mg and what the early weeks involve. The relationship between the starting dose and weight loss outcomes is a question our prescribers hear regularly, and the honest answer is that the 0.25 mg period is about tolerability, not results.

One practical point worth knowing: if you start treatment shortly before a bank holiday, or your first order arrives mid-week, your four-week review still runs from your actual first injection date. The schedule follows your pen, not the calendar.

What the full semaglutide titration ladder looks like

The standard Wegovy schedule has five steps. Weeks 1–4 at 0.25 mg; weeks 5–8 at 0.5 mg; weeks 9–12 at 1.0 mg; weeks 13–16 at 1.7 mg; from week 17 onward at 2.4 mg as the original maintenance dose. With the MHRA's approval of a 7.2 mg dose in 2026, a further titration step is now available for eligible patients, but that higher dose is only reached after a patient has been established at lower maintenance levels, and it applies to adults with a BMI of 30 or above. You can read more about the full Wegovy dose range and how each step fits into the overall treatment arc.

The NHS summarises the semaglutide titration schedule clearly in its patient-level guidance on semaglutide, and that page is a useful reference if you want to cross-check the steps. A few things are worth flagging: the schedule assumes you tolerate each dose well enough to advance. If side effects are significant at any step, a prescriber may keep you at the current level for longer rather than pushing upward. Rushing to a higher dose when your body is still adjusting does not accelerate weight loss and tends to worsen nausea. Patience at the lower steps is part of the treatment, not a failure of it.

People sometimes ask about beginning at 0.5 mg rather than 0.25 mg, for example, if they have previously used a GLP-1 medicine. That is a clinical decision, not one to make unilaterally, and would require a prescriber to assess what prior treatment you have had and how recently.

Who the semaglutide starting schedule applies to, and what comes first

The licensed eligibility criteria for Wegovy cover adults with a BMI of 30 or above, or a BMI of 27–29.9 alongside at least one weight-related health condition, such as high blood pressure, high cholesterol, or obstructive sleep apnoea. Lower BMI thresholds apply for some ethnic backgrounds under UK clinical guidance. BMI alone does not determine clinical suitability; a prescriber considers the whole picture, including medical history, current medicines, and whether any conditions contraindicate treatment.

Wegovy is not recommended during pregnancy, breastfeeding, or when trying to conceive. It is not licensed for anyone under 18. History of pancreatitis or certain thyroid conditions requires specific discussion with a prescriber before treatment begins. These are not fine print, they are the reason a clinical consultation precedes every prescription. The Wegovy treatment overview covers eligibility in more detail, and our clinical team reviews every consultation personally.

If you are considering treatment and want to understand the cost involved in private prescribing, the Wegovy pricing page sets out what is included in a legitimate private prescription. For anything else about the process, our FAQs cover the most common questions, and the weight-loss treatment overview sets the broader context for how GLP-1 medicines fit into a wider approach.

If semaglutide sounds like something you'd like to explore, speak to our prescribers through a free consultation, reviewed the same day by a GPhC-registered Independent Prescriber, with no algorithm in the loop.