Wegovy and weight loss drugs: what semaglutide actually does

Is Wegovy the right weight loss drug for you, or would something else fit better?

This is a question our prescribers hear most weeks, and the honest answer depends on more than BMI alone. Wegovy (semaglutide) works on one gut-hormone receptor (the GLP-1 pathway) slowing gastric emptying and reducing hunger signals so you naturally eat less over time. For most people that mechanism is effective. Clinical trials found an average of roughly 15% body-weight reduction over 68 weeks at the 2.4mg maintenance dose.

The main alternative in this class is tirzepatide (Mounjaro), which activates two receptors rather than one. Head-to-head data from the SURMOUNT-5 trial showed greater average weight loss with tirzepatide than with semaglutide 2.4mg, though the newer 7.2mg Wegovy dose narrows that gap. If you want a broader picture of how Wegovy compares with other weight loss drugs, including where each one tends to fit in clinical practice, that page sets out the options clearly. Neither medicine suits everyone, and a prescriber weighs your full medical picture (not just a number on the scales) before recommending one over the other.

If injections put you off, the MHRA approved Wegovy as an oral tablet in June 2026. The Wegovy tablet page covers how it differs from the injection, including its once-daily morning routine and room-temperature storage.

What the eligibility criteria for semaglutide weight loss drugs actually mean in practice

The licensed criteria for Wegovy are straightforward on paper: BMI of 30 or above, or 27–29.9 alongside a weight-related health condition. In practice, a prescriber also looks at your medical history, current medicines, and any contraindications — including a personal or family history of medullary thyroid carcinoma, certain GI conditions, and a history of pancreatitis.

On the NHS, access is narrower. NICE's appraisal of semaglutide (TA875) recommends it only within specialist weight management services, for a maximum of two years, for people with a BMI of 35 or above and at least one weight-related comorbidity. The threshold sits about 2.5 kg/m² lower for people of South Asian, Chinese, Middle Eastern, Black African or African-Caribbean backgrounds. Waiting lists for those services are long in most parts of England.

Private treatment through a regulated pharmacy follows the broader licensed criteria. You can read more about how Wegovy works for weight loss and what a typical treatment journey looks like. Eligibility is still confirmed by a prescriber, not a form, no checklist replaces clinical judgement.

Side effects that genuinely influence the decision to use semaglutide

Gastrointestinal effects dominate the early weeks: nausea, constipation, loose stools, reflux and burping appear most often after starting treatment or after each dose step. For most people they are uncomfortable rather than dangerous, and they tend to ease within a week or two as the body adjusts. The titration schedule (moving from 0.25mg up through 0.5mg, 1mg, 1.7mg to the maintenance dose over several months) exists specifically to give the gut time to adapt.

A small number of people experience more serious effects. The MHRA highlighted acute pancreatitis as an infrequent but potentially serious risk in a Drug Safety Update issued in January 2026: seek urgent medical help for severe stomach pain that radiates to the back, especially with vomiting. Gallbladder symptoms and dehydration from prolonged vomiting also warrant prompt attention. You can report any suspected side effects through the MHRA Yellow Card scheme.

Wegovy is not recommended during pregnancy, whilst breastfeeding, or if you are trying to conceive. It is not licensed for anyone under 18. These are firm positions, not precautionary hedges, a prescriber will discuss the wash-out period before conception if that is relevant to you.

Cost, supply and how to access Wegovy through a legitimate UK service

Cost is part of the decision for most people. On the NHS it is free, but access depends on meeting the NICE criteria and being referred to a specialist service. Privately, prices vary by dose and provider; the background context on Wegovy pricing in the UK explains what typical market rates look like and why headline figures often exclude consultation fees, prescription costs and aftercare.

Supply has improved since the Medicines and Healthcare products Regulatory Agency lifted the prescribing restriction for weight management in 2024, but availability still varies. People also sometimes ask whether combining supplements with their treatment makes a difference, and our page on apple cider vinegar and Wegovy looks at what the evidence actually says on that question. Always verify that any online pharmacy supplying semaglutide is registered with the GPhC, the GPhC online register lets you check any UK pharmacy in seconds. Sellers offering weight loss drugs without a prescription, or using discount codes as an incentive, are red flags for counterfeit supply.

At nume, every consultation is read by a GPhC-registered Independent Prescriber on the day it is submitted. There are no automatic approvals and no subscriptions. If semaglutide weight loss treatment is clinically suitable for you after that review, speak to our prescribers to get started.