Wegovy 0.25mg: what happens in your first four weeks

Step 1: why every Wegovy course starts at 0.25mg, not higher

Wegovy (semaglutide) is a GLP-1 receptor agonist that slows gastric emptying and reduces appetite through gut-hormone signalling. Those same mechanisms that curb hunger can, at full therapeutic doses, produce significant nausea, vomiting and diarrhoea, particularly in people who have never taken a GLP-1 medicine before.

Starting at 0.25mg gives the gut time to adapt. The prescribing schedule, as described in the NHS semaglutide medicine guide, sets 0.25mg as the opening step for exactly this reason: tolerability, not weight loss, is the goal of week one through four. Think of it as calibration rather than treatment in the full sense.

This is worth knowing before you start, because some people feel slightly underwhelmed at 0.25mg (appetite suppression may be mild, the scales may barely move) and that is exactly as intended. The clinical data supporting Wegovy's average weight loss of around 15% over 68 weeks in the STEP 1 trial was built on a full titration to 2.4mg, not on the starter pen alone. Patience at this stage pays off later.

For a broader overview of how all the Wegovy doses relate to each other, the Wegovy doses guide covers the full titration schedule in detail, and if you want to go deeper on the Wegovy starting dose of 0.25mg, that page explains the rationale behind the opening pen in full.

Step 2: what 0.25mg Wegovy actually feels like, side effects and what to watch for

Most people find 0.25mg their most comfortable week in the entire titration. Gastrointestinal effects (nausea, loose stools, indigestion, mild burping) are typically mild at the lowest dose and become more noticeable with each upward step. That said, "mild" is relative; some people do feel queasier than expected at the start, and it is worth knowing the pattern so you are not caught off-guard.

Nausea tends to peak in the day or two after each injection and settles as the week goes on. Eating smaller portions and avoiding very rich or fatty meals in those first 24 to 48 hours can help. One practical habit worth building now: check the injection-site area before each weekly dose, the abdomen, thigh and upper arm are all suitable, and rotating between them reduces local skin reactions over time. It takes under a minute and saves soreness across months of treatment.

Serious reactions are rare but need prompt attention. Severe, persistent stomach pain that reaches through to the back, with or without vomiting, should prompt urgent medical review, the MHRA Yellow Card scheme exists for reporting any suspected side effect from a licensed medicine, and your prescriber should know immediately if anything concerns you.

For a fuller breakdown of what to expect as 0.25mg Wegovy begins working, the 0.25mg Wegovy results page goes into more detail about early weight changes.

Step 3: moving on (what happens after the four-week starter phase

At the end of four weeks on 0.25mg, the schedule moves to 0.5mg for another four weeks, then 1.0mg, 1.7mg and finally 2.4mg) each step held for at least a month to allow adaptation. Wegovy's higher 7.2mg maintenance dose, approved by the MHRA in April 2026 via a dedicated single-dose pen, extends the ladder further still for eligible adults with a BMI of 30 or above, as confirmed by the MHRA's announcement on gov.uk.

Titration pace is set by the prescriber, not by the patient. If side effects are significant at any stage, the prescriber may recommend staying at a dose for longer before stepping up. The 0.25mg phase itself is fixed, it is not a dose that anyone skips, even if they have taken a lower-dose GLP-1 medicine previously. Switching products, gaps in treatment and other clinical factors all affect what happens next; the prescriber reviews the full picture before any change.

If you are trying to understand how the device delivering 0.25mg works, the Wegovy FlexTouch 0.25mg pen guide covers the mechanics of the pre-filled pen. And for context on what the broader Wegovy treatment involves, the Wegovy overview gives the wider picture in one place.

Cost is a reasonable question at this point in your research. The Wegovy cost guide for UK patients sets out what private treatment typically involves, including what a transparent price should cover. Private prescription is the route most people take outside of NHS specialist services, and any legitimate price includes a clinical assessment, not just the pen.

At nume, every consultation is read by a GPhC-registered Independent Prescriber on the same day it arrives, a real clinician, working through your answers personally. If you have questions about whether Wegovy is right for you, or about the titration process, speaking to our prescribers is a straightforward next step.