Compare Mounjaro, Wegovy and Saxenda in the UK

Mounjaro, Wegovy and Saxenda are three prescription-only weight management treatments licensed for use in the UK. They belong to the same broad family of injectable medicines that act on gut hormone pathways, but they use different active ingredients, follow different dosing schedules and are priced differently by each provider. This hub is built to compare those practical differences side by side so you can prepare for a consultation, not to decide which medicine is right for you.

The table below summarises the core distinctions. Everything after it explains the mechanism, dosing, evidence, safety, eligibility and cost structure in more depth, followed by how we check provider information and the factors worth discussing with a prescriber.

Dosing is where the practical routine of each treatment diverges. Mounjaro and Wegovy are weekly treatments: after an introductory period you inject once a week. Saxenda is a daily treatment, injected once every day at a similar time. Whether a weekly or daily schedule suits you is a genuine lifestyle question worth raising in a consultation.

All three follow a titration plan. You begin at a low starting dose to help the body adjust and reduce early side effects, then move through a structured dose escalation over several weeks until you reach a maintenance dose. The starting dose is not the dose most people stay on, which matters when you compare cost: early months on a low dose can be cheaper than later maintenance months.

The pen format also varies. Wegovy is commonly supplied as pre-filled single-dose pens tied to a specific strength, Saxenda as a multi-dose adjustable pen, and Mounjaro in pen formats that depend on strength and supplier. Because of this, some pharmacies quote a price per pen and others per pack, so it helps to translate any quote into a monthly treatment cost for the dose you expect to use.

Across all three medicines, the most commonly reported side effects are gastrointestinal: nausea, diarrhoea, constipation, indigestion and reduced appetite, especially in the early weeks and when the dose increases. For many people these ease over time, which is part of why treatment starts low and builds gradually.

Each product also carries less common but more serious risks — such as pancreatitis and gallbladder problems — which are listed in the summary of product characteristics and patient information leaflet for that specific medicine. There are contraindications and cautions, including certain personal or family medical histories, that make a treatment unsuitable for some people.

Because these are prescription-only medicines, safety monitoring is part of proper care. Always read the leaflet for the product you are actually prescribed, report side effects to your clinician, and seek urgent advice for severe or persistent symptoms. Our helpful guides add general context, but they do not replace medical advice.

There are two broad routes to these medicines in the UK. NHS access, where it is available, follows national and local pathway rules, specific eligibility criteria and service capacity, and can involve waiting lists or specialist clinic referral. Availability differs by region and by medicine.

Private access is usually faster and is self-funded through a registered online pharmacy or clinic after a consultation. This hub focuses on private provider pricing because that is where costs vary most and where a clear comparison helps. If you want to explore NHS options, speak to your GP or an NHS weight-management service about whether you qualify.

The headline pen or pack price is only part of what you pay. A realistic monthly treatment cost usually combines the medicine itself with any consultation fee, a delivery charge for tracked or temperature-controlled shipping, and the repeat price on future orders. Some providers bundle these into one figure; others list them separately.

This is why the cheapest headline medicine is not always the lowest total cost. A provider with a slightly higher pen price but no consultation fee and free delivery can work out cheaper over several months than one with a low medicine price and added charges at checkout. Projecting the total cost across the months you expect to be on your maintenance dose is the fairest way to compare.