Wegovy is semaglutide 2.4mg, a once-weekly GLP-1 injection made by Novo Nordisk and licensed in the UK for weight management. The dose is stepped up over 16 weeks to reduce side effects; the most common effects are gastrointestinal. In the STEP 1 trial the average weight change was about -14.9% over 68 weeks.[2] NHS access is limited to a specialist weight-management service and set criteria, so many people obtain it privately — but a prescriber always decides first. This is an information page: it names no seller and carries no prices.
What Wegovy is, and how it works
Wegovy is a brand of semaglutide, made by Novo Nordisk, and it belongs to the family of medicines people search for as "GLP-1 medication", "GLP injections" or a "GLP-1 drugs list". Semaglutide is a GLP-1 receptor agonist: it mimics a natural gut hormone called GLP-1 (glucagon-like peptide-1). Medicines in this class reduce appetite, slow stomach emptying and increase fullness, helping people eat less and lose weight.[1]
Semaglutide is a peptide engineered into a long-acting form, which is what makes once-weekly dosing possible.[1] In the UK, Wegovy is licensed as a weight-management medicine to be used alongside a reduced-calorie diet and increased physical activity, for adults with a body mass index (BMI) of 30 or more, or a BMI of 27 to under 30 together with at least one weight-related health problem; it is also licensed for some adolescents aged 12 and over who have obesity and weigh more than 60 kg.[1] It is not a stand-alone fix, and it is one option a prescriber may discuss — not something you must take.
The weekly pen: how Wegovy is given
Wegovy is given as an injection under the skin (subcutaneously) once a week, into the abdomen, thigh or upper arm.[1] It is supplied as a pre-filled FlexTouch pen; each pen contains four once-weekly doses, and a pack includes four disposable NovoFine Plus needles.[1] The unopened pens are kept refrigerated at 2–8 °C in their original carton and must not be frozen; limited short-term storage at higher temperatures is allowed, so the patient information leaflet in the box is the instruction that counts.[1]
The dose ladder: from 0.25mg up to 2.4mg
Nobody starts on the full dose. Like the rest of the GLP-1 class, semaglutide is titrated — started low and increased in stages — because side effects are dose-related and worst while the dose is climbing. The step-up to the 2.4mg maintenance dose takes 16 weeks:[1]
| Weeks | Once-weekly dose | Role |
|---|---|---|
| 1–4 | 0.25mg | Starting dose (not a treatment dose) |
| 5–8 | 0.5mg | Titration step |
| 9–12 | 1mg | Titration step |
| 13–16 | 1.7mg | Titration step |
| 17 onward | 2.4mg | Maintenance dose |
That gradual climb is deliberate: it exists to reduce dose-related gastrointestinal side effects, and it is not optional pacing.[1] A prescriber, not the patient, controls how quickly the dose rises, and a step can be held longer if side effects are a problem.
A higher 7.2mg once-weekly maximum dose has since been authorised in the UK — first in January 2026 (initially given as three separate 2.4mg injections on the same day), with a single-dose 7.2mg pen approved by the MHRA on 14 April 2026 for adults with obesity (BMI 30 or more). Standard treatment still begins at 0.25mg weekly and steps up roughly every four weeks.[3]
What the STEP trials showed
Wegovy's weight-management licence is built on the STEP trials. The headline trial for adults without diabetes is STEP 1: a 68-week, double-blind study of 1,961 adults. Average weight change was -14.9% with semaglutide 2.4mg compared with -2.4% on placebo, and 86% of people on semaglutide lost at least 5% of their body weight.[2]
A figure like "about 15% weight loss" is a trial average, not a promise. Individual results vary widely, the trial paired the medicine with diet and activity support, and weight tends to return if treatment stops. Averages describe a group, not any one person.
A figure of around 13.6% you may see elsewhere belongs to the oral tablet (the "Wegovy pill"), not the STEP 1 injection — different products. We cover the tablet on our Wegovy pill (oral semaglutide) page, and set the injections and tablets side by side in our comparison of the GLP-1 medicines.
UK status: licence and the NHS position
Getting a medicine funded on the NHS works through two gates: the MHRA licenses it, then NICE appraises whether the NHS should pay for it, and for whom. Wegovy has cleared both, but the NHS route is deliberately narrow.
Under NICE guidance TA875, semaglutide (Wegovy) is recommended only within a specialist weight-management service, for a maximum of two years, for people meeting set BMI and comorbidity criteria; treatment is stopped if less than 5% of body weight is lost after six months on the maintenance dose.[5] NICE also lowers the BMI thresholds — usually by 2.5 kg/m² — for people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family backgrounds, recognising that health risk arises at a lower BMI.[6]
Because that NHS route is narrow, many people who use weight-loss GLP-1 medicines obtain them privately, through a regulated prescriber and pharmacy rather than the NHS. We state that as the current access reality, not a recommendation: a prescriber still decides whether the medicine is appropriate, and — as an information site — we name no provider and carry no prices.
Side effects and safety
Across the GLP-1 class the most common effects are gastrointestinal, usually mild to moderate, dose-related and worst while the dose is increased; they tend to settle over weeks.[1] For Wegovy, the UK product information lists these as very common — affecting at least 1 in 10 people:
| Effect | Reported frequency |
|---|---|
| Nausea | 43.9% |
| Diarrhoea | 29.7% |
| Vomiting | 24.5% |
| Constipation | 24.2% |
Common effects (up to 1 in 10 people) include headache, dizziness, abdominal pain, indigestion, wind, gallstones, hair loss (around 2.5%) and a small average rise in heart rate (about 3 beats per minute).[1] The product information also sets out warnings a prescriber weighs up first: acute pancreatitis (treatment is stopped if it is suspected), dehydration and, rarely, kidney problems from severe nausea, vomiting or diarrhoea, gallbladder disease, and — in people with diabetes — an increased risk of diabetic eye (retinopathy) complications.[1] The only contraindication listed in the UK product information is a known allergy to semaglutide or the other ingredients; everything else is handled as a warning or precaution — which is why a full consultation covering your medical history and other medicines matters first.[1]
If you take Wegovy or any weight-loss medicine and have a suspected side effect, report it through the MHRA Yellow Card scheme[7] and speak to your GP or pharmacist. Because these medicines are in high demand, they are a common target for counterfeiters: prescription medicines bought from unregulated websites or social-media sellers may be falsified, wrongly dosed or contaminated, and buying a prescription-only medicine without a prescription is unlawful. The government's FakeMeds campaign explains how to check that a seller is legitimate.
Wegovy, Ozempic and the Wegovy pill: not the same thing
This trips a lot of people up. Wegovy, Ozempic and Rybelsus all contain the same molecule — semaglutide — but they are licensed and dosed differently and are not interchangeable. Wegovy injection is licensed in the UK for weight management, at the 2.4mg once-weekly maintenance dose above.[1] Ozempic is the same molecule licensed for type 2 diabetes only, so weight-loss use is off-label; the MHRA advises Wegovy as the licensed weight-loss route and says it has not assessed these medicines outside their licensed use.[4] The "Wegovy pill" is a once-daily oral tablet form of semaglutide, with its own dose ladder — see our Wegovy pill page. Mounjaro (tirzepatide) is a different molecule again, not semaglutide; we cover it on the Mounjaro page.
Frequently asked questions
What is Wegovy and how does it work?
Wegovy is a brand of semaglutide, a GLP-1 receptor agonist made by Novo Nordisk, given as a once-weekly injection and licensed in the UK for weight management. It mimics the gut hormone GLP-1 to increase fullness, slow stomach emptying and reduce hunger, so people eat less. It is used alongside diet and activity, and is prescription-only.[1]
How is Wegovy taken, and what is the dose ladder?
A once-weekly injection under the skin of the abdomen, thigh or upper arm, using a pre-filled FlexTouch pen. The dose rises over 16 weeks — 0.25mg (weeks 1–4), 0.5mg, 1mg, then 1.7mg — reaching the 2.4mg maintenance dose from week 17.[1] A higher 7.2mg maximum dose has since been authorised in the UK.[3] The step-up reduces side effects, and a prescriber controls the pace.
How much weight did people lose with Wegovy in trials?
In the 68-week STEP 1 trial of 1,961 adults without diabetes, average weight change was about -14.9% with semaglutide 2.4mg versus -2.4% on placebo, and 86% lost at least 5% of their body weight.[2] Individual results vary; a trial average is not a promise.
Can I get Wegovy on the NHS?
Sometimes, but access is narrow. NICE guidance TA875 recommends Wegovy only within a specialist weight-management service, for up to two years, for people meeting set BMI and health criteria, and treatment stops if less than 5% of body weight is lost after six months on the maintenance dose.[5] Because NHS access is limited, many people use it privately — but a prescriber decides first.
What are the most common Wegovy side effects?
Mostly gastrointestinal. In the UK product information the very common effects (at least 1 in 10 people) are nausea (43.9%), diarrhoea (29.7%), vomiting (24.5%) and constipation (24.2%).[1] They are usually mild to moderate and often settle over time. Report any suspected side effect through the MHRA Yellow Card scheme.[7]
References
- Wegovy (semaglutide) — UK Summary of Product Characteristics (mechanism, once-weekly 2.4mg dosing, FlexTouch pen, dose-escalation schedule, storage, side-effect frequencies, contraindications and warnings). electronic medicines compendium (emc), product 13803. medicines.org.uk
- Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). New England Journal of Medicine, 10 February 2021. nejm.org
- MHRA / GOV.UK. Single-dose 7.2mg semaglutide (Wegovy) pen approved to treat adult patients with obesity (7.2mg authorised January 2026; single-dose pen approved 14 April 2026). gov.uk
- MHRA / GOV.UK. MHRA updates guidance for semaglutide prescribers and patients (Ozempic licensed for type 2 diabetes; weight-loss use off-label; safety/effectiveness not assessed outside licensed use). gov.uk
- NICE. Semaglutide for managing overweight and obesity — Technology appraisal guidance TA875, recommendations (specialist weight-management service, maximum two years, 5% stop rule at six months). nice.org.uk
- NICE. Weight-management technology appraisal recommendations — lowered BMI thresholds (usually by 2.5 kg/m²) for certain family backgrounds. nice.org.uk
- MHRA. Yellow Card scheme — report a suspected side effect. yellowcard.mhra.gov.uk