Which Weight Loss Drug Is Best? UK Options Compared (October 2026)

01 · The short answer

Which weight loss drug is best for you?

No licensed medicine is best for everyone; your prescriber judges which is safe and suitable for you, because effectiveness on paper means little if you cannot tolerate it, afford it or stay on it. Lists titled "best weight loss drugs" tend to rank products by headline trial results, yet those averages do not predict your own result. Individual results vary, and the medicines are used alongside a reduced-calorie diet and increased physical activity.

In the UK, the injectable options most people compare are Mounjaro and Wegovy, both once weekly, and liraglutide, which is a daily injection. Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly.¹ In the UK it is licensed for weight management in adults and for type 2 diabetes.¹ Wegovy is semaglutide, taken once weekly on a stepped ladder of 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg, with 2.4mg the licensed maintenance dose.¹⁸

Three questions help you decide. Do you meet the licensed criteria? Do you take other medicines, such as insulin or oral contraceptives, that need planning around? If you use the oral contraceptive pill: 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 And what can you realistically sustain, in cost and in injection routine? A prescriber review covers all of these. Our weight loss clinic starts with a free online consultation reviewed by a GPhC-registered prescriber, with no obligation.

02 · Our approach

How we judge options without hype

A medicine that is licensed in the UK has been assessed for quality, safety and effectiveness by the regulator. A medicine in development has not, and a medicine sold online without a prescription has not been assessed for you at all. Our guide to the safest prescription weight loss drugs goes deeper on that distinction.

Cost matters too. Across the UK pharmacies we track, Mounjaro pens range from £143.96 to £339.00 per month depending on dose and provider, checked 10 October 2026. At the starting dose, the cheapest and dearest 2.5mg pens run from £143.96 to £179.99. Our own standard 2.5mg pen is £169.99, and the Mounjaro pen page shows live pricing and whether doses are in stock.

03 · What to do next

What to do next

If you are weighing up weight loss drugs, start by checking whether you meet the licensed criteria and talk through your medical history with a prescriber. If Mounjaro looks right, the consultation is free, the price shown is the price paid, and an order that is not suitable is refunded automatically. A new customer's first order carries a discount with code FIRST40, and every later order gets an automatic reorder discount.

If you would rather read more first, our guide to what has changed in new weight loss drugs explains the wider picture. You can also look at our best weight loss drugs discount code page to see how the current offers work.

04 · Licensed UK options

Licensed weight loss drugs in the UK

The licensed injectable weight loss medicines you are most likely to be offered in the UK are tirzepatide, semaglutide and liraglutide. Each comes with product information that sets out who it is for, how to dose it and what to watch for.

Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly.¹ In the UK it is licensed 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 The low strengths are for building up gradually, and your prescriber reviews whether to step up at each stage.

Wegovy is the brand of semaglutide for weight management. Its pens are 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg once weekly, and the dose steps up after at least four weeks, reaching the 2.4mg maintenance dose from week 17.¹⁸ The 2.4mg dose is the licensed maintenance dose for weight management.¹⁸ A pen of Wegovy is not interchangeable with a pen of Mounjaro, because the active ingredients and dose scales differ entirely.

Liraglutide, supplied as Saxenda and in other products, comes at a concentration of 6mg per millilitre. It is a daily injection, unlike once-weekly Mounjaro and Wegovy. Some people prefer to avoid a daily routine; others prefer it.

Choosing between these is rarely about a single number. It is about your history, how you respond to the early doses, the side effects you can live with and how much you can budget each month. If you want a wider view of how the options compare, our guide to whether the new weight loss drugs work sets out realistic expectations.

Wegovy's NHS access runs through specialist weight-management services; ask your GP. If you pay privately, Wegovy's first pen is £99.99 as a first-order price, and you should check availability at the time of order.

Whichever medicine you consider, remember that these are prescription-only treatments. They are supplied only after a consultation reviewed by a GPhC-registered prescriber, and they work alongside a reduced-calorie diet and increased physical activity. Individual results vary, and no responsible provider promises specific results.

05 · How Mounjaro works

How Mounjaro works

Mounjaro works by acting on two gut-hormone pathways that help regulate appetite. 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 is the key point to hold on to: the medicine makes eating less easier, but it does not remove the need to change what and how you eat. People who treat it as one part of a wider plan, with protein, regular meals and activity, are better placed to keep what they achieve.

This dual action is what distinguishes Mounjaro from single-action GLP-1 medicines such as semaglutide (Wegovy/Ozempic).¹ Whether that difference matters for you personally is something a trial average cannot tell you. Some people respond well to one medicine and poorly to another, and a prescriber can adjust the plan over time.

Because tirzepatide stays in the body for some time, it is worth understanding how long. 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, and there is no way to speed this up.¹ Nothing needs doing while it clears. This is relevant if you are planning a pause, a switch to another medicine or a change in circumstances; talk to your prescriber before you stop.

Doses are built up slowly across the six strengths so the body can adjust. Your prescriber reviews how you are feeling before agreeing each step, and our ongoing monthly reviews are there for exactly that reason.

Like all medicines, Mounjaro can cause side effects, and most are digestive. The most common, affecting more than 1 in 10 people, are nausea, diarrhoea, vomiting, constipation and abdominal discomfort. Side effects are most likely when starting treatment or moving up a dose, and for most people they ease within days to a few weeks as the body adjusts. Tell your prescriber about any new or lasting symptom, and you can report suspected side effects through the MHRA Yellow Card scheme.

06 · New and upcoming drugs

New and upcoming weight loss drugs

New weight loss drugs fall into three groups: licensed tablets that are now available, medicines still in development, and products that are only marketed as if they were medicines.

Oral options are the headline development. Wegovy tablets (oral semaglutide) and Foundayo (orforglipron) each have their own UK product information, which you can read on the electronic medicines compendium.²⁰²¹ Separate trials in different groups of people cannot be compared as if they were a head-to-head test.

Beyond those, many compounds are in development. Some target more hormone pathways than current medicines do. Others are older drug classes being re-examined. Until a regulator has assessed a medicine, claims about it are provisional. Headlines about a "drug better than Mounjaro" usually describe early-stage results, and early results often change as larger studies report.

What does this mean if you want to start treatment now? Waiting for a hoped-for medicine means waiting without treatment, while licensed medicines already exist. If a new medicine is licensed in the UK later, your prescriber can discuss whether it makes sense to switch. That decision should come from your own history and response, not from a news cycle.

Be especially wary of sellers advertising upcoming or "next-generation" drugs before they are licensed. A medicine that is not licensed cannot be lawfully supplied for weight loss in the UK through a regulated pharmacy, and products offered by sellers who offer to supply without a consultation or prescription may be counterfeit or unregulated. The MHRA publishes counterfeit medicine alerts and runs the Yellow Card scheme for reporting problems.⁷

For a plain-English look at the safety question around newer products, see our guide on whether new weight loss drugs are safe. For a wider explainer on what has changed recently, our new weight loss drugs guide keeps the picture current.

The practical rule is straightforward. Choose a medicine because it is licensed, appropriate for you and available through a regulated pharmacy, and keep an open mind about newer options as they are licensed. Until then, a prescriber-led plan with an existing licensed medicine is a sound route.

07 · Safety and side effects

Safety and side effects of weight loss drugs

Safety depends on the medicine, your health and what else you take, so the safest weight loss drug is the one a prescriber has checked against your history. Every licensed medicine has a patient information leaflet and a summary of product characteristics that list known effects, and these are the right place to look rather than online individual accounts.

For Mounjaro, the leaflet is the reference for side effects, and it is worth reading before your first dose.¹³ Digestive effects such as nausea are the type most often discussed, and they tend to show most when a dose is increased. If you have severe or persistent stomach pain, or signs of a severe allergic reaction, get medical help straight away; for other unexpected symptoms, get medical help straight away. You can also report suspected side effects through the MHRA Yellow Card scheme.¹⁹

Two interaction points deserve plain statements. Mounjaro slows stomach emptying, which can reduce how well oral contraceptive pills are absorbed. Switch to a non-oral method, or add a barrier method (such as condoms), for 4 weeks after starting Mounjaro and for 4 weeks after each dose increase.⁷ And if you take insulin or sulfonylureas, doses may need adjusting because of the risk of low blood sugar; this is something to plan with your prescriber, not to manage alone.¹

If you notice something new, speak to your prescriber and consider a Yellow Card report.

Which is safer, Mounjaro or Wegovy? Both are licensed medicines with their own safety information, and neither can be named as safer for everyone. The right question is which has the better risk profile for you, given your conditions and other medicines, and a prescriber is the person to answer that. Our guide to the safest prescription weight loss drugs walks through the factors.

The same caution applies to anything marketed as a natural alternative. Low-cost supplements sold as a "poor man's Ozempic" are not medicines with the same assessment behind them. They carry no clinical oversight and dosing is not standardised. Calling a supplement a substitute for a licensed medicine is a marketing claim, not evidence.

Other drug types, such as amphetamine drugs for weight loss or products promoted in bodybuilding weight loss drugs circles, have different risk profiles and different regulation.

08 · NHS versus private

NHS or private: how access works

You can get weight loss drugs through the NHS or privately, and the right route depends on whether you meet the NHS criteria now and how long you are willing to wait. Both routes lead to the same licensed medicines; the difference is access, speed and cost to you.

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.⁶

The NHS guide to the medicine explains who it is for and how it is used, and is a good neutral read before you decide.⁵ If you think you may qualify, ask your GP what the local position is. If you would like to start sooner, or do not meet the NHS thresholds, a private route is the alternative. NHS access to Wegovy runs through specialist weight-management services; ask your GP.

Private treatment is not a shortcut around clinical checks. A regulated online pharmacy is registered with the General Pharmaceutical Council, and you can verify us on the GPhC public register under registration 9012878.¹² Our consultation is free, reviewed by a GPhC-registered prescriber rather than a scoring script, and if an order is unsuitable it is refunded automatically. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.

Choosing private care also brings a decision about cost. The ongoing price is the standard price of your dose, less the automatic reorder discount on every future order.

A reasonable approach for many people is to do both: join any NHS list you are eligible for, and treat privately in the meantime if that suits you. Tell your NHS clinician about any private treatment so your records stay accurate. Whichever way you go, ongoing review matters, and our monthly reviews, dose titration and follow-up assessments by the prescribing team are included.

If you are unsure which category you fall into, the consultation questionnaire is short, free and carries no obligation. It is the quickest way to find out whether a licensed medicine is appropriate for you.

09 · Costs across a year

What weight loss drugs cost over a year

The cost of weight loss drugs is best judged across a year, because the dose you settle at changes the monthly price. For Mounjaro, the first four pens of building up (four pens: 2.5mg, 5mg, 7.5mg and 10mg) cost £959.96 at standard prices, before discounts. A new customer's first order is £40 less with code FIRST40, and an automatic £25 reorder discount applies to every future order (code DOSE25).

Over a first year, someone who settles at 5mg pays £2,711.88 at standard prices, while someone who settles at 15mg pays up to £3,599.88. For other maintenance doses, use that dose's monthly price: £279.99 at 7.5mg, £290.99 at 10mg, and £319.99 at 12.5mg. Every later order is £25 off the standard price.

Your first 2.5mg pen costs £129.99 with code FIRST40 (standard price £169.99). If you are switching to us at the top strength, your first order is £289.99. These are first-order prices only, so check the live Mounjaro pen page for today's figures, stock and the delivery cut-off of 3pm for same-day dispatch.

The pharmacy market is uneven. Across the UK pharmacies we track, the gap between providers for the same dose ranges from £27 to £41, and Boots lists Mounjaro from £179.00 to £339.00 depending on dose, checked 10 October 2026. Our figures are dated so you can compare like with like.

Pharmacy sell prices vary because of confidential discounts, which is why we show live figures rather than static ones.

Payment options include Visa and Mastercard, Klarna and pay-monthly plans, with no subscriptions and no auto-shipping. Delivery is free next-day tracked, in temperature-controlled packaging; Saturday delivery is £14.99. Needles, a sharps bin and injection guidance come with every order. For how the current offers work, see our discount code guide.

Remember also that a cheap medicine is not good value if it is unsuitable. The price shown is the price paid, the consultation is free, and an order that a prescriber declines is refunded in full automatically.

10 · Storage and genuine supply

Storage, supply and avoiding fakes

Genuine supply and correct storage are what make a weight loss pen safe to use, so both deserve attention before your first injection. Counterfeit and unregulated pens are a recognised problem, and the MHRA publishes alerts about them.⁷ Buying from a pharmacy listed on the GPhC register is the simplest protection, and our registration number is 9012878.¹²

We source Mounjaro through official LillyDirect supply, direct from Eli Lilly's UK distribution, so the KwikPens you receive are genuine. All six doses from 2.5mg to 15mg are stocked, and availability is shown live as in stock on the product page. Be cautious of any seller offering to supply without a consultation or prescription, whatever the price or the claims.

For storage, keep unopened pens in the fridge between 2–8°C until first use; they keep until the printed expiry date.¹³ Once you start using a KwikPen, it can be kept out of the fridge at a temperature not above 30°C for up to 30 days after first use, and must then be thrown away. Do not use a pen that has been above 30°C or frozen.¹ If you are unsure about an unopened pen that has been out of the fridge, check the patient information leaflet and ask the pharmacy rather than guessing, because outside the tested window sterility and potency are no longer assured.

Our deliveries use temperature-controlled, discreet packaging with tracked next-day delivery, so a pen should arrive in good condition. If an item arrives faulty, damaged or incorrect, contact us promptly; dispensed prescription medicines cannot otherwise be returned.

Follow the pen's instructions for injecting, and use the sharps bin we include for needles. If something about the pen or the injection seems wrong, stop and ask us or your prescriber before continuing.

The same discipline applies to anything marketed as a substitute. Over-the-counter supplements promoted as natural alternatives are low-cost and available without assessment, but they are not licensed weight loss medicines and carry no clinical oversight.

If you have questions about storage, a dose or a side effect, our support team is available Monday to Friday, 9am to 5pm, by email at support@everydaymeds.co.uk, through the account portal chat, or by phone on 0333 207 0413. The free GLPTrackr companion app, for iOS and Android, also helps you keep track of doses and how you feel.

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 · Ordering with us

How ordering works

Ordering a weight loss medicine from us follows a short, regulated journey: a free consultation, a prescriber review, dispensing and dispatch, then delivery. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.

First, complete the free online consultation. It is a short health questionnaire with no charge and no obligation. Second, your answers are reviewed by a GPhC-registered prescriber, 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. Third, our registered pharmacy dispenses your medicine, with same-day dispatch when you order by 3pm. Finally, your pen arrives by free next-day tracked delivery in temperature-controlled, discreet packaging.

After your first order, support does not stop. Ongoing monthly reviews, dose titration and follow-up assessments are carried out by the prescribing team, with side-effect support when you need it. Repeat orders re-check suitability each time, and there is no auto-shipping, so you stay in control of when you order. You can see our weight loss drugs pharmacy page for more on how this works in practice.

We are a full UK online pharmacy rather than a weight-loss shop; we also provide treatments for sexual health, hair loss and acid reflux. More than 100,000 customers have been supported on their weight loss journey, which describes how many people we have served, not how any individual will respond. Results vary.

Costs are laid out openly. Your first 2.5mg pen costs £129.99 with code FIRST40 (standard price £169.99), every later order is £25 off the standard price, and there are no hidden fees. Klarna and pay-monthly options are available, with no subscription lock-in. Prices were checked 10 October 2026.

If you are not ready to order, the sensible next step is simply to read, compare and talk to a prescriber when you are ready. Weight loss drugs are a long-term decision, and a good provider will not rush you. Start with the Mounjaro pen prices and consultation page when you want to see what is available today.

Mounjaro (tirzepatide) is a prescription-only medicine, supplied only after an online consultation reviewed by a GPhC-registered prescriber. It is used alongside a reduced-calorie diet and increased physical activity. Individual results vary. This page is information, not a substitute for medical advice.