What's the lowest dose of Wegovy — and what does it actually do?

You've just been told you're starting at 0.25 mg, here's why that feels underwhelming

It's a question our prescribers hear regularly: "Why am I on such a tiny dose?" You've read about the clinical trial results, you're motivated, and 0.25 mg sounds like a fraction of what actually works. That frustration is understandable.

The 0.25 mg dose exists for one reason: your digestive system needs time to adapt to semaglutide. GLP-1 receptor agonists slow the rate at which food leaves the stomach, and that effect can cause nausea, burping and loose stools if it arrives at full strength from week one. Starting low keeps those effects manageable while your gut adjusts. Think of it as the first rung of a clinical ladder, not the landing.

The full Wegovy dose schedule moves in roughly four-week steps: 0.25 mg, then 0.5 mg, then 1.0 mg, then 1.7 mg, and finally 2.4 mg as the standard maintenance dose. A prescriber decides whether each step happens on schedule or whether you need a longer period at a given level before moving up. That is a clinical call, not a self-managed one. The NHS guidance on weight-management injections also sets this out clearly for anyone comparing private and NHS-route expectations.

If you want to understand whether this first dose does anything at all for weight, the evidence on 0.25 mg Wegovy is worth reading before you form a conclusion.

What the 0.25 mg pen looks like in daily life

Most people inject on the same day each week, often settling on a routine that fits around their schedule, before the morning commute, or just after the kids leave for school, for example. The injection site can be the abdomen, thigh or upper arm; rotating between sites reduces localised irritation.

At 0.25 mg, the appetite-suppressing effect of semaglutide is mild. Some people notice a modest reduction in hunger in the first week or two; others feel little difference at all. That is expected. The pharmacology at this dose is genuinely sub-therapeutic for weight loss, even though it is active enough to start the GI adaptation process.

Side effects tend to peak during the early weeks and after each dose increase. Nausea is the most commonly reported, followed by constipation, indigestion and tiredness. These are generally mild to moderate and transient. The NHS semaglutide medicines page lists the full side-effect profile with plain-English guidance on what to do if symptoms persist.

Storing the pen correctly matters from day one: refrigerate it at 2–8°C and consult the Patient Information Leaflet for the exact window during which a pen can safely be kept at room temperature. That window is shorter than most people assume, so check the leaflet rather than guessing.

If you're wondering whether it's possible to stay at 0.25 mg rather than moving up, the answer involves more clinical nuance than a simple yes or no.

Where 0.25 mg sits in the full Wegovy picture

The STEP 1 trial, published in the New England Journal of Medicine, reported an average body-weight reduction of around 15% over 68 weeks at the 2.4 mg maintenance dose, alongside lifestyle changes. That figure is reached after months of titration, not at 0.25 mg. It is cited here not to lower expectations but to frame the starting dose correctly: the 0.25 mg pen is the beginning of a clinical process, and the results data reflects where that process leads.

In January 2026 the MHRA approved a 7.2 mg maintenance dose, initially delivered as three 2.4 mg pens weekly. A dedicated single-dose 7.2 mg pen followed in April 2026, approved for adults with a BMI of 30 or above. Trials at this higher dose reported average weight loss of around 20.7% over 72 weeks, closer to tirzepatide results. For context on how semaglutide and tirzepatide compare across dose levels, the Wegovy overview covers the key differences.

Whether the 7.2 mg pen is right for a given patient is decided at consultation and depends on individual response, tolerance and clinical history. Availability of specific pen formats is confirmed during that conversation, not assumed in advance.

If your goal is to understand the ceiling, the maximum licensed Wegovy dose and its evidence base is covered in full separately. And for anyone comparing the cost of private treatment at any stage of the schedule, how to find a legitimate Wegovy prescriber in the UK is worth reading alongside the price context.

Getting started: what a clinical assessment involves

Wegovy is licensed in the UK for adults with a BMI of 30 or above, or 27 or above alongside at least one weight-related condition such as high blood pressure, type 2 diabetes, high cholesterol or obstructive sleep apnoea. A lower BMI threshold applies for some ethnic backgrounds under NICE guidance. BMI alone does not determine suitability; the prescriber reviews your medical history, current medicines and any contraindications as part of the assessment.

Pregnancy, breastfeeding, and trying to conceive are all situations in which Wegovy is not recommended; the same applies to under-18s. Anyone with a history of medullary thyroid carcinoma, MEN2, or certain gastrointestinal conditions needs to discuss this with a prescriber before starting.

At nume, every consultation is read and decided by a GPhC-registered Independent Prescriber, not automated software. There is no waiting list. If you're ready to find out whether you're clinically suitable, our prescribers are available seven days a week and review consultations the same day. Start your free consultation when you're ready.