Wegovy 0.25 mg: what is this starting dose actually for?

Why does Wegovy start at such a low dose?

The 0.25 mg figure often surprises people who expected to feel a dramatic change in appetite immediately. It won't, and it isn't supposed to. Semaglutide is a GLP-1 receptor agonist: it slows gastric emptying and signals the brain to reduce hunger. Those same mechanisms, introduced too quickly, produce nausea, vomiting, diarrhoea and constipation in a significant number of people. The 0.25 mg starter dose keeps the effect modest while your gut adapts.

Think of it as the first week of a new exercise routine. The load is deliberately light. If your prescriber rushed you to 2.4 mg on day one, the dropout rate from side effects would be far higher. The clinical evidence base for Wegovy (including the STEP 1 trial published in the New England Journal of Medicine) was built on this exact titration structure, which means skipping steps undermines the safety profile the trial demonstrated.

Your prescriber, not the packaging, decides whether you move up after four weeks. If your side effects are still significant, they may hold you at 0.25 mg a little longer. That is a clinical call, not a failure.

What does the full dose schedule look like from here?

After 0.25 mg, the licensed schedule moves through 0.5 mg, then 1 mg, then 1.7 mg, reaching the 2.4 mg maintenance dose, each step roughly four weeks apart. You can read a detailed breakdown of how the steps differ on the Wegovy doses overview. The 2.4 mg dose is where the weight-loss evidence sits: in the STEP 1 trial, participants lost an average of around 15% of body weight over 68 weeks at this maintenance dose.

There is now a higher licensed dose above 2.4 mg. The MHRA approved a 7.2 mg option in 2026, and if you are curious how these higher-strength formulations are developing, our page on Novo's high dose Wegovy programme in the EU gives useful background on where that pipeline is heading. Specific dose availability is always confirmed at consultation rather than assumed.

Each pen is pre-filled to its dose. You inject once a week, on the same day each week where possible, into the abdomen, thigh or upper arm, rotating sites. The pen itself is discreet (small, pre-set, covered needle) and once you have done it the first time, most people find the routine straightforward. When your order is dispatched by our GPhC-registered pharmacy, it arrives via DPD the next working day in plain, unbranded packaging; you get a tracking link so you know exactly when it will turn up.

For practical detail on moving through the schedule, the 1 mg step and the full Wegovy medicine overview both cover what to expect at later stages, and if you want to look ahead, our guide to the 2 mg Wegovy dose explains what that stage of the schedule involves.

What side effects are most likely at 0.25 mg?

Gastrointestinal effects dominate the side-effect profile of semaglutide at every dose, but they tend to be at their most noticeable when treatment starts and whenever the dose increases. At 0.25 mg specifically, the lower exposure means many people experience only mild symptoms, queasiness after the first injection or two, looser stools, or a modest reduction in appetite that feels unfamiliar rather than uncomfortable.

The side effects to know about at any stage include nausea, vomiting, diarrhoea, constipation, indigestion, reflux and fatigue. Headache and dizziness are also reported. Most settle within a few days to two weeks. Eating smaller meals, avoiding high-fat foods early on, and staying well hydrated all help.

Rare but serious effects require prompt medical attention: severe, persistent abdominal pain that extends into the back can be a sign of pancreatitis, the MHRA has specifically highlighted this in its guidance on GLP-1 medicines. Gallbladder-related symptoms and allergic reactions are also flagged in the prescribing information. If something feels wrong, contact your GP or 111 rather than waiting for your next check-in.

You can report any suspected side effect through the MHRA Yellow Card scheme. Prescribers and patients can both submit reports; it is one of the ways post-market safety evidence accumulates for newer medicines like Wegovy.

Who is eligible to start Wegovy, and how does the prescription process work?

The licensed eligibility criteria for Wegovy cover adults with a BMI of 30 or above, or a BMI of 27 to 29.9 alongside at least one weight-related condition such as high blood pressure, high cholesterol, type 2 diabetes, prediabetes or obstructive sleep apnoea. BMI thresholds are set slightly lower for some ethnic backgrounds under UK clinical guidance. Meeting the BMI figure alone does not guarantee a prescription; a prescriber assesses the whole picture, including your medical history, any contraindications and your current medicines.

Wegovy is not recommended during pregnancy, while breastfeeding, or when actively trying to conceive. It is not licensed for people under 18. Anyone with a history of medullary thyroid carcinoma, MEN2 syndrome or certain gastrointestinal conditions should discuss this specifically with a prescriber before starting.

On the NHS, access is routed through specialist weight management services under NICE guidance TA875, which attaches specific criteria and a maximum two-year treatment period. Waiting lists vary. Private treatment through a regulated online pharmacy is the alternative for people who do not meet the NHS criteria or prefer not to wait, provided they are clinically suitable. If you want to understand the costs involved in private treatment, the Wegovy pricing context page covers what to expect.

A clinician at our prescribing service reviews every consultation personally before any prescription is issued. Speak to our prescribers to find out whether Wegovy is the right starting point for you.