What semaglutide is actually used for — and what it isn't

The biggest misconception: Ozempic is not a weight-loss medicine

The most widespread confusion around semaglutide is the idea that Ozempic (the weekly injection most people have seen discussed online) is a weight-loss treatment. It isn't, not in the UK. Ozempic holds an MHRA licence for controlling blood glucose in adults with type 2 diabetes. It happens to cause weight loss in many people who take it for that purpose, but that is a side effect of the glucose-lowering mechanism, not a licensed indication. Prescribing Ozempic specifically to manage weight in someone without type 2 diabetes would be off-label use.

Wegovy is the licensed weight-management version. It contains the same molecule (semaglutide) but at a higher maintenance dose (2.4 mg weekly, rising to 7.2 mg with the pen approved in April 2026) and is specifically indicated for adults with a BMI of 30 or above, or 27 or above with at least one weight-related health condition. The NHS medicines page for semaglutide sets this out plainly and is worth reading if you want the patient-level summary. For a fuller picture of how Wegovy fits into weight management in practice, the Wegovy overview on this site covers eligibility and the titration pathway in detail.

Rybelsus adds a third product: oral semaglutide tablets, licensed for type 2 diabetes at 3 mg, 7 mg and 14 mg doses. These are not the same as the Wegovy tablet (approved by the MHRA on 11 June 2026 for weight management at doses up to 25 mg). The two oral products share a molecule but serve different conditions at entirely different dose ranges.

What the weight-management licence actually covers

NICE assessed semaglutide (Wegovy) for weight management and published its recommendation in TA875. The NHS makes it available through specialist weight management services, subject to strict criteria, a BMI of 35 or above plus at least one weight-related comorbidity, used for a maximum of two years within a multidisciplinary programme. Lower BMI thresholds apply for people from South Asian, Chinese, Middle Eastern, Black African or African-Caribbean backgrounds under NICE's guidance.

Private prescribing follows the licensed SmPC rather than the NHS commissioning criteria, so the eligibility picture differs slightly. A prescriber at a GPhC-registered pharmacy such as nume will assess BMI, weight-related conditions, medical history and any contraindications before issuing a prescription. BMI alone is never the whole picture, a person with a BMI just above the threshold but with significant other health factors may be more clinically suitable than someone whose only consideration is BMI. That is precisely why a clinical review exists. If you want to understand the practical conditions semaglutide is used for beyond the headline BMI figure, that page goes into more depth.

A quick check you can do right now: the NHS BMI calculator at nhs.uk takes under a minute and gives you a starting reference point before any consultation.

The newer indications: cardiovascular risk and liver disease

Semaglutide's licensed uses have expanded beyond weight management and diabetes. Wegovy gained MHRA authorisation for reducing the risk of major cardiovascular events (heart attack and stroke) in eligible adults with established cardiovascular disease and obesity or overweight. This was a meaningful clinical development: a weight-management medicine with a separate, evidence-backed cardiovascular indication is unusual.

More recently, on 3 July 2026, the MHRA granted conditional approval for semaglutide (Wegovy) to treat MASH (metabolic dysfunction-associated steatohepatitis, a progressive form of fatty liver disease) in adults with moderate-to-advanced fibrosis. That makes it one of the first systemic medicines approved for this indication in the UK. The MHRA's announcement sets out the scope of that conditional authorisation. These are specialist indications; nume prescribes semaglutide for weight management, and readers with questions about cardiovascular or liver indications should discuss them with their GP or specialist.

For a broader look at how the full range of Wegovy's licensed uses sits alongside the weight-management pathway, that page covers all current UK indications in one place.

Side effects and what to watch for

Across all its licensed uses, semaglutide's side-effect profile is dominated by gastrointestinal effects. Nausea, loose stools, constipation, reflux and fatigue are the most commonly reported, particularly in the first weeks of treatment or after a dose increase. For most people these settle as the body adjusts, but they can be significant enough to affect daily life during early titration.

Less common but more serious: on 29 January 2026 the MHRA issued a Drug Safety Update for GLP-1 medicines, including semaglutide, flagging acute pancreatitis as an infrequent but potentially serious risk. The symptom to act on is severe, persistent abdominal pain that radiates to the back, that warrants urgent medical attention, not a wait-and-see. Gallbladder problems, dehydration from prolonged vomiting, and allergic reactions are also listed in the prescribing information.

Semaglutide is not recommended during pregnancy, whilst breastfeeding, or for anyone trying to conceive. It is not licensed for use in under-18s. Anyone already taking the injection who wants to understand how semaglutide interacts with the rest of their health picture (including oral contraceptives or HRT) should raise this with their prescriber. Our semaglutide information page covers the safety profile in more detail, and if you are working through the titration schedule you can read about how semaglutide 1 works as the starting dose and then about what moving to semaglutide 2 involves when the time comes. The FAQs section picks up the questions our clinical team hears most often. If weight management is where your interest lies, checking your eligibility is a sensible next step.