New Weight Loss Injection UK: What Is Actually Available (October 2026)

01 · The short answer

What is the new weight loss injection?

For most UK adults, the answer is Mounjaro (tirzepatide). It is a once-weekly prescription injection made by Eli Lilly, licensed in the UK for weight management in adults and for type 2 diabetes.¹ It comes as a pre-filled multi-dose pen (KwikPen) in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.¹

It is called new because it is the first treatment of its kind to activate two natural gut-hormone receptors at once: GIP and GLP-1.¹ That separates it from older single-action GLP-1 medicines such as semaglutide (Wegovy and Ozempic). Our guide to the new weight loss drugs in the UK covers the wider landscape.

The other name in the news is retatrutide. It is still being developed, it is not licensed in the UK, and no UK pharmacy can lawfully prescribe it.

02 · Compare

Licensed, tablet or still in development?

This table sorts the names you are likely to see.

If you want to see how this plays out in practice, our page on the new weight loss drug injection goes through the same names in more detail.

03 · Next step

Is a new injection relevant to you?

It may be if you are an adult who wants help with weight alongside a reduced-calorie diet and more physical activity. Mounjaro is a prescription-only medicine, supplied only after an online consultation reviewed by a GPhC-registered prescriber, and individual results vary.¹

Two decisions face most readers. The first is whether to wait for something newer. Waiting for an unlicensed medicine means waiting for an unknown date, whereas licensed treatment is available now and is reviewed by a prescriber as you go. The second is NHS or private. The NHS route is being phased in, so you may want to read about the new NHS injection for weight loss before deciding.

If you are ready to look at private treatment, the Mounjaro pen page shows every dose and the live prices, and our weight loss clinic page explains how we work. Your first 2.5mg pen costs £129.99 with code FIRST40 (standard price £169.99), and all six doses are in stock.

04 · What counts as new

What actually counts as a new weight loss jab

The phrase new weight loss jab covers several very different things. A medicine can be new to the UK, new to a particular patient group, new as a tablet, or new only in the sense that it appears in a news story. Only some of these are available to you.

The licensed injectable options in the UK are Mounjaro and Wegovy, both taken once weekly, and liraglutide, which is a daily injection supplied at 6mg/ml.¹ Of these, Mounjaro is the one most people mean when they say new, because it is the first treatment to activate two natural gut-hormone receptors at once: GIP and GLP-1.¹ It is licensed in the UK for weight management in adults and for type 2 diabetes.¹

Wegovy is semaglutide, a single-action GLP-1 medicine. Its licensed ladder is 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg once weekly, and the 2.4mg dose is the licensed maintenance dose for weight management. It is not new in the way Mounjaro is, but it remains a well-established option; our new fat loss injection page compares these names.

Tablets form a separate category. GLP-1 tablets have reached the UK market, but they are not injections, and no trial has compared Mounjaro directly with either tablet. If tablets interest you, our page on a new weight loss pill after injections looks at that specific question.

Finally, there is the pipeline: medicines that are still being studied and have no UK licence. They make good headlines but are not something you can be prescribed. Treat any website that sells one as a warning sign, not an opportunity. A regulated pharmacy supplies only licensed medicines after a consultation, and you can check any UK pharmacy on the GPhC register. Ours is registered under 9012878.

So when someone asks what the name of the new injection to lose weight is, the honest answer is that there is no single name. The newest licensed option is Mounjaro (tirzepatide).

05 · How tirzepatide works

How the new dual-action injection works

Tirzepatide is the first treatment of its kind to activate two natural gut-hormone receptors at once: GIP and GLP-1.¹ Together these help regulate appetite, slow how quickly the stomach empties, and improve the way the body responds to insulin.¹ In practice, most people feel fuller sooner and less hungry between meals, which supports a reduced-calorie diet.¹

That last point deserves emphasis. The injection does not replace eating differently or moving more. It makes a reduced-calorie diet easier to follow by changing hunger signals. People who treat it as a shortcut tend to be disappointed, while people who use the quieter appetite to build habits tend to do better. Your prescriber will talk this through at the start and at each review.

This dual action is what distinguishes Mounjaro from single-action GLP-1 medicines such as semaglutide (Wegovy and Ozempic).¹ Be careful with what that does and does not mean. It describes a difference in mechanism. It does not by itself tell you which medicine will suit you better, and individual response varies with both.

Because the stomach empties more slowly, the medicine can reduce absorption of oral contraceptives. The SmPC advises switching to a non-oral method, or adding a barrier method (such as condoms), for 4 weeks after starting Mounjaro and for 4 weeks after each dose increase.¹ If you use one, tell your prescriber so the right precautions can be agreed, and see the MHRA guidance for detail.⁷ If you take insulin or a sulfonylurea, doses may need adjusting because of the risk of low blood sugar, so make sure your prescriber knows everything you take.

Tirzepatide has a half-life of about five days, so after a final dose it takes roughly four to five weeks to clear the system.¹ There is no way to speed this up, and nothing needs doing while it clears.

If you are comparing the different names in the news, remember that mechanism is only one factor. Practical points matter just as much: how often you inject, how the dose ladder works, what the side effects feel like, how reviews are handled and what the medicine costs over time.

06 · What trials found

What the trial results say, and what they do not

In the SURMOUNT-1 trial of 2,539 adults, people taking tirzepatide alongside diet and exercise lost on average 15% of their body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone.²

These are trial averages. Individual results vary, and treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.² Trial averages do not predict your own result: some people lose more, some lose less, and a few have little response.

The same trial reported how many people reached particular milestones. At 72 weeks, 85% of participants on 5mg, 89% on 10mg and 91% on 15mg had lost at least 5% of their body weight. Half of participants on 10mg and 57% on 15mg lost at least 20% of their body weight.²

For a worked example, for someone starting at 100 kg, 20.9% is about 21 kg. That is simple arithmetic on an average, not a promise, and it was reached over 72 weeks, which is well over a year of treatment.

This is why pace matters. Weight loss on Mounjaro 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.¹ Trials measured results at 72 weeks, so think in months, not days, and judge progress by trend, not individual weigh-ins.

Your prescriber reviews how you respond. 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.¹ That honest checkpoint is part of why a clinical review matters more than a quick checkout.

A caution on headlines. Figures quoted for medicines still in development come from studies that have not led to a UK licence, and results from different trials, in different populations and over different durations, cannot be set side by side as if they were a head-to-head contest. NICE has assessed tirzepatide for managing overweight and obesity, and its guidance is the reference point for NHS use.⁴

07 · Dosing and injecting

How the dose ladder and weekly injection work

Everyone starts Mounjaro on 2.5mg once a week. This starting dose is about letting your body adjust, not about weight loss itself.¹ After at least 4 weeks the dose increases to 5mg, and can then step up by 2.5mg at a minimum of 4-week intervals (7.5mg, 10mg, 12.5mg) up to a maximum of 15mg weekly, depending on how you respond and tolerate it.¹

Many people settle at a maintenance dose of 5mg, 10mg or 15mg. Higher is not automatically better, and your prescriber will guide the right pace.¹

Mounjaro is injected under the skin (subcutaneously) once a week, on the same day each week, at any time of day, with or without food.¹ Licensed injection sites are the stomach area (at least 5cm from the belly button), the front of the thigh, or the back of the upper arm if someone else gives the injection. Rotate the site with each dose. Each KwikPen contains four weekly doses.

There is no best time of day. Mounjaro works the same morning or evening, with or without food. What matters is the same day each week. Many people choose a weekend morning so early side effects fall on days off.

Always follow the pen's instructions, and the patient information leaflet.¹³

If you miss a dose, take it as soon as you can within 4 days (96 hours) of the scheduled time, then carry on with your usual day. If more than 4 days have passed, skip the missed dose entirely and take the next one on your normal day. Never take two doses within 3 days of each other. You can change your weekly injection day if needed, as long as at least 3 days (72 hours) have passed since your last dose.

08 · Retatrutide and the pipeline

Retatrutide and what is coming next

Retatrutide is still in development and is not licensed in the UK. That means no UK pharmacy can prescribe it, and no prescriber can supply it to you today.

Is retatrutide the same as Mounjaro? No. They are different medicines made by the same company, with different active ingredients. Mounjaro contains tirzepatide, which is licensed and has an approved dose ladder, a patient leaflet and a track record of prescribing in the UK. Retatrutide does not have those things in this country.

Studies in different populations, over different lengths of time, are not directly comparable, and early results are not a promise about how a medicine will perform once it is assessed by a regulator. When a licence decision is made for the UK, that is the moment to look again.

What about the question of what new weight-loss drugs are coming next? Several are under study, including newer injections and further tablet options. Which of them reach UK patients, and when, is decided by regulators and by NICE. Our guide to the new weight loss jab this year tracks what has genuinely changed.

The practical risk is this. Whenever a medicine is in the news and unavailable, sellers appear offering it anyway. Products sold as retatrutide, or as a vial or pen of something unspecified, are not licensed medicines and have not been through UK quality checks. Sellers offering to supply without a consultation or prescription should be avoided entirely, because you cannot know what is in the product, how it was stored, or whether it is sterile.

If you do see a suspected counterfeit or unlicensed product, the MHRA runs the Yellow Card scheme, which accepts reports of side effects and suspected problem products.⁷¹⁹ If you have already taken something from an unverified source and feel unwell, get medical help straight away.

Meanwhile, waiting rarely makes sense. A licensed treatment today, with prescriber oversight, is a better basis for a health decision than a hoped-for treatment on an unknown date. If something new is later licensed, you can discuss it with your prescriber then.

09 · NHS and private routes

NHS or private: how access works

Mounjaro is available on the NHS, but access is being phased in over several years.⁴ NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition, and the NHS 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, which is why many people who meet the licensed criteria choose regulated private treatment rather than waiting.

What does that mean for you? The simplest first step is to ask your GP whether you fall into a group currently being offered treatment. If you do, the NHS route is worth pursuing. If you do not, or you are unsure how long you would wait, private treatment is a legitimate alternative that follows the same licence. Our page on the new NHS injection for weight loss goes deeper on this.

Wegovy follows a different path: NHS access to Wegovy runs through specialist weight-management services, so ask your GP.

Private treatment is not a lesser version. The medicine, the licence and the dose ladder are the same. What differs is how you reach it. With us, the journey is a free online consultation, a review by a GPhC-registered prescriber, dispensing by our registered pharmacy, and delivery. We do not charge for the consultation, and the price shown is the price paid. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.

Across the UK pharmacies we track, cheapest to dearest pen prices run from £143.96 to £339.00 (checked 12 October 2026), and the gap between providers for the same dose ranges from £27 to £41.

For us, standard prices run from £169.99 at 2.5mg to £329.99 at 15mg. A new customer saves £40 on their first order with code FIRST40, and an automatic £25 reorder discount applies to every future order (code DOSE25). The first four pens (2.5mg to 10mg), if you step up after 4 weeks on each dose, total £959.96 at standard prices before discounts. 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. For a detailed breakdown, see the cost of the new weight loss injection.

10 · Safety and storage

Early effects, storage and staying safe

The first weeks are about adjustment, and experiences differ widely. Some people notice appetite change and early loss in week one, others feel little until a higher dose, and both are normal. Early loss includes water weight, so the trend over weeks matters more than any single weigh-in. Mild nausea, altered appetite and tiredness in the first days after each injection are the commonest early effects and usually settle.¹³

The patient information leaflet and the SmPC are the authoritative sources, and your prescriber will go through them with you.¹¹³ Report any new or worrying symptom to your prescriber, and you can also report suspected side effects through the MHRA Yellow Card scheme.¹⁹

No food is banned on Mounjaro, including bananas, but smaller, slower meals often work better because the stomach empties more slowly. For medicines, tell your prescriber about everything you take, including insulin, sulfonylureas and oral contraceptives, because some need adjusting or extra precautions.⁷ Do not stop or change another prescribed medicine on your own.

Storage is straightforward. Keep Mounjaro pens in a fridge at 2–8°C and never freeze them. Once in use, a pen can be kept out of the fridge at a temperature not above 30°C for up to 30 days after first use, which is useful for short trips, and must then be thrown away. Keep the pen cap on to protect it from light, and do not use a pen that has been above 30°C or has been frozen.¹

You can fly with Mounjaro. Carry pens in hand luggage, because hold luggage can fall below freezing, ideally in a cool bag with the prescription label or a copy of your prescription. For hot climates use an insulated pouch, and check destination rules for travelling with prescription injectables before you fly. Unopened pens should be kept in the fridge and keep until the expiry date printed on the box. If an unopened pen has been out of the fridge, check with the pharmacy before using it rather than relying on a remembered day limit, because figures circulating online often come from other countries' labels.

On counterfeits, buy only from a pharmacy you can find on the GPhC register, and be wary of any seller offering to supply without a consultation or prescription.⁷ We supply Mounjaro through official LillyDirect supply, direct from Eli Lilly's UK distribution, as genuine KwikPens.

11 · Serious side effects

Serious side effects: when to get help straight away

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. If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion) — your prescriber may need to adjust those medicines.¹

12 · Choosing and ordering

Choosing what is right for you, and how ordering works

The right choice depends on you, not on which name is trending. Start by asking whether you fit the licensed use: Mounjaro is licensed for weight management in adults, used alongside a reduced-calorie diet and increased physical activity.¹ Then consider practical factors: whether you prefer a weekly or daily injection, how you feel about needles, your other medicines, and your budget over a full year rather than a single month.

If you are comparing Mounjaro with Wegovy, both are licensed once-weekly options and a prescriber can help you decide between them. Neither is automatically right for everyone. If you are considering tablets, remember they are a different category with their own labelling, and you should not assume the results map across.

Do not plan around a medicine that is not yet available. If you are curious about the next generation, it is reasonable to read about it, but a decision to start treatment should rest on what is licensed and available now, with a prescriber who can review you.

Ordering with us follows a short path:

• Free online consultation. A short health questionnaire with no charge and no obligation.
• Prescriber review. A GPhC-registered prescriber reviews it, not a scoring script. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.
• Dispensing and delivery. Our registered pharmacy dispenses, with same-day dispatch when ordered by 3pm, then free next-day tracked delivery in discreet, temperature-controlled packaging. Saturday delivery is £14.99.

Needles, a sharps bin and injection guidance come with every order. Ongoing monthly reviews, dose titration and follow-up assessments are handled by the prescribing team, and repeat orders re-check suitability, with no auto-shipping and no subscription. You can pay by Visa or Mastercard, Klarna, or pay-monthly options. Our free GLPTrackr app helps you track your journey. Support is available Monday to Friday, 9am to 5pm, by email at support@everydaymeds.co.uk, through the account portal chat, or on 0333 207 0413.

When you are ready, the Mounjaro pen page shows current prices and starts your consultation. Your first 2.5mg pen costs £129.99 with code FIRST40, and prices were last checked 12 October 2026. If you are switching from another provider at a higher dose, your first order is discounted too: at 15mg it is £289.99.