Wegovy 0.5mg: the second step on the titration ladder

Why does Wegovy start so low and climb through 0.5mg?

Semaglutide is a GLP-1 receptor agonist: it slows the speed at which food leaves the stomach, raises feelings of fullness, and dials down appetite signals in the brain. Those same mechanisms can also cause nausea, burping, or loose stools, particularly in the first weeks. The titration schedule (0.25mg, 0.5mg, 1.0mg, 1.7mg, 2.4mg, each held for around four weeks) is built around that reality. Starting at a fraction of the maintenance dose lets your digestive system adjust before the therapeutic effect fully kicks in.

The 0.5mg step is the first time most people notice semaglutide beginning to change their appetite in a more tangible way, though the scale of that effect varies considerably from person to person. Gastrointestinal side effects are most common around the time a new dose begins and usually settle within one to two weeks, according to the NHS semaglutide patient information page. Pressing through to a higher dose before your system is ready tends to make those symptoms worse and harder to manage, which is why the four-week minimum exists.

One practical detail: the injection is administered once weekly, and many people find it easiest to build the dose day into a routine, a Sunday evening, a Monday morning before the kettle has boiled. Consistency matters less to the medicine than it does to you, but a reliable anchor helps you avoid missed doses.

Is 0.5mg where the weight-loss effect actually begins?

The honest answer is: it begins to build here, but the stronger effects come later in the schedule. The STEP 1 clinical trial, published in the New England Journal of Medicine, showed an average body-weight reduction of around 15% over 68 weeks at the 2.4mg maintenance dose. That headline figure is the result of sustained treatment at maximum tolerated dose, not of two or four weeks at 0.5mg.

That said, many people report early changes to hunger and portion size within the first few weeks, even at lower doses. These experiences are real, but they are not clinically defined weight-loss outcomes. The titration phase is about laying the foundation, not measuring progress against the trial results.

What matters most at 0.5mg is how well you are tolerating the medicine. If side effects are manageable and your prescriber is satisfied with how things are going, the dose progression continues. If not, the prescriber may hold you at 0.5mg for an additional four weeks before moving forward. That flexibility is one reason clinical review at each stage matters. You can read more about how Wegovy works across the full schedule to understand what changes as the dose increases.

What side effects should I be aware of at this dose?

The side-effect profile at 0.5mg is broadly the same as at other steps, though intensity varies between individuals. The most frequently reported effects are gastrointestinal: nausea, constipation, diarrhoea, indigestion, and occasionally vomiting. These tend to be most noticeable in the first week or two at a new dose level and often reduce without any change to treatment.

A small number of people experience fatigue, headache, or dizziness, particularly early on. Injection-site reactions (mild redness or tenderness) are possible but uncommon. None of these effects need to be pushed through in silence. Your prescribing team is there to advise, and if a symptom is persistent or severe, that is a reason to contact them before moving to the next dose.

One symptom that warrants urgent attention at any dose: severe abdominal pain that extends toward the back, with or without vomiting. This may indicate pancreatitis, which the MHRA has highlighted as an infrequent but serious risk with GLP-1 medicines, seek medical help promptly if this occurs rather than waiting for your next appointment. Report any unexpected or serious reactions via the MHRA Yellow Card scheme. Semaglutide carries a Black Triangle (▼) symbol, meaning the MHRA is collecting additional safety data as part of routine post-approval monitoring.

Wegovy is not recommended during pregnancy, while breastfeeding, or when actively trying to conceive. It is not licensed for anyone under 18. Your prescriber will have reviewed these points during your initial consultation, but they remain relevant if your circumstances change.

Can I stay on 0.5mg long-term rather than increasing?

This is a question worth raising directly with your prescriber rather than deciding alone. The licensed pathway is designed to reach 2.4mg as the maintenance dose, and the clinical evidence underpinning NICE's recommendation for semaglutide (summarised in NICE technology appraisal TA875) reflects outcomes at that level. Staying at 0.5mg indefinitely is not standard practice and would be a clinical decision made in light of your individual tolerance, response, and any other health factors.

Some people are held at an intermediate dose for a period if side effects make further progression difficult. That is different from electing to remain there permanently. If your current dose feels manageable but you are nervous about increasing, that conversation belongs with your prescriber, who can weigh the evidence against your specific situation. There is also a broader question about how Wegovy is prescribed in the UK private sector, if you are considering starting treatment or switching provider, our guide to accessing Wegovy through a regulated UK pharmacy explains what the process involves.

Understanding how semaglutide compares to other options, or how the dose schedule works in practice, can also help you have a more informed conversation. You can explore semaglutide as a medicine in more depth, or read about what the Wegovy 0.5mg dose involves and how it fits into the broader schedule, and if you want detail on moving through the Wegovy 0.5mg phase, that page covers what to expect as you progress. You can also read about what to expect around week five of treatment when some people are approaching or beginning the 1.0mg step. If you have specific questions about your own treatment, our prescribers review queries seven days a week, speak to our prescribers if you'd like a clinical perspective on where you are in the schedule.