Names of Prescribed Injections for Weight Loss in the UK (October 2026)

01 · The names

The prescribed weight loss injections available in the UK

The licensed prescription injections are Mounjaro (tirzepatide), Wegovy (semaglutide) and Saxenda (liraglutide). Mounjaro and Wegovy are injected once a week. Liraglutide, sold as Saxenda and in products such as Erly, is a daily injection supplied at 6mg per millilitre.

Semaglutide acts on one gut-hormone receptor, GLP-1. Tirzepatide acts on two, GIP and GLP-1, which is what distinguishes Mounjaro from single-action medicines such as Wegovy.¹

02 · Cost

What Mounjaro costs privately

The Mounjaro pen costs £169.99 per month at the 2.5mg starting dose, rising to £329.99 at 15mg, standard prices. New customers save £40 on their first order with code FIRST40, and an automatic £25 reorder discount applies to every future order (code DOSE25). If you step up after 4 weeks on each dose, your first four pens (2.5mg to 10mg) cost £959.96 at standard prices. A first year costs £2,711.88 if you stay on 5mg after your 2.5mg starting pen, up to £3,599.88 if you step up through every dose to 15mg. Across the UK pharmacies we track, Mounjaro pens range from £143.96 to £339.00 depending on dose and provider (checked 10 October 2026).

03 · How to get one

How to get a prescribed injection from us

Ordering takes three steps; see how to buy Mounjaro for more detail.

• Complete the free online consultation, a short health questionnaire with no obligation.
• A GPhC-registered prescriber reviews it. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.
• Our registered pharmacy dispenses it, with same-day dispatch when ordered by 3pm and free next-day tracked delivery in temperature-controlled packaging.

We supply genuine KwikPens through official LillyDirect supply, direct from Eli Lilly's UK distribution. Be wary of anyone offering to supply without a consultation or prescription: these medicines are prescription-only, and counterfeit alerts are published by the MHRA.⁷ You can check our registration (GPhC 9012878) on the GPhC register.

04 · Who is eligible

Who can be prescribed a weight loss injection

Mounjaro is licensed for adults with a BMI of 30 or above, or a BMI between 27 and 30 with at least one weight-related condition such as high blood pressure, high cholesterol, obstructive sleep apnoea, cardiovascular disease, prediabetes or type 2 diabetes. It must be used alongside a reduced-calorie diet and increased physical activity. A prescriber assesses your BMI, medical history and current medicines before deciding whether it is suitable.¹

NHS or private?

Mounjaro is available on the NHS, but access is being phased in over several years. NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition. The primary-care rollout began in June 2025 with the highest-need groups first, initially BMI 40+ with four or more qualifying conditions.⁴⁶ Full rollout is expected to take years, so many people who meet the licensed criteria choose regulated private treatment. If your GP will not prescribe it, that is often because you do not yet fall within the current NHS group. Ask your GP which stage applies to you.

05 · What results to expect

What results to expect on Mounjaro

In SURMOUNT-1, 2,539 adults taking tirzepatide alongside diet and exercise lost on average 15% of body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, against 3.1% with lifestyle changes alone.² For someone starting at 100 kg, 20.9% is about 21 kg. These are trial averages and individual results vary.

At 72 weeks, 85% on 5mg, 89% on 10mg and 91% on 15mg had lost at least 5% of their body weight.²

The first three months

Weight loss is gradual by design. The first weeks on 2.5mg are an adjustment phase and losses are usually modest. Most measurable progress builds from 5mg onward, month by month. Early loss includes water weight, so judge the trend rather than single weigh-ins.¹ If you have lost less than 5% of your starting weight after 6 months on the highest dose you can tolerate, your prescriber will discuss whether continuing or stopping is right for you.

06 · Dosing and first month

How Mounjaro dosing and the first month work

Everyone starts on 2.5mg once a week. After at least 4 weeks the dose rises to 5mg, then can step up by 2.5mg at minimum 4-week intervals to a maximum of 15mg. Many people settle at 5mg, 10mg or 15mg; higher is not automatically better.¹

It is injected under the skin on the same day each week, at any time of day, with or without food. Each KwikPen holds four weekly doses. Mild nausea, altered appetite and tiredness in the first days after each injection are the commonest early effects and usually settle.¹³ Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing. You can report suspected side effects through the Yellow Card scheme, and you should tell your prescriber about any new or lasting symptom.¹⁹ Our prescribing team provides monthly reviews and side-effect support.

07 · Injections that are not the same

Other injections sold for weight loss

Some clinics advertise vitamin, lipotropic or "fat-dissolving" injections. See our guides on ALA injections, hydroxocobalamin injections, Beplex Forte injections and carboxy injections. Our related guides on the prescribed weight loss injection and the name of the injection for weight loss go further, and you can compare every option under all weight loss treatments.

Mounjaro (tirzepatide) is a prescription-only medicine, supplied only after an online consultation reviewed by a GPhC-registered prescriber. Individual results vary. This page is information, not a substitute for medical advice.