The 2025 Mounjaro Price Rise: What Happened and What It Means

In August 2025, Eli Lilly announced that it would raise the UK list price of Mounjaro (tirzepatide), with the new prices taking effect from 1 September 2025. The increase applied to private supply and was largest at the higher strengths, with widely reported rises of around 170% at the top doses. Lilly said the price paid by the NHS was not changing. The change affected the many people in the UK who use Mounjaro privately for weight management, prompting some to review their treatment plans. This guide explains what happened, why, and what it means if you are taking or considering Mounjaro. We do not quote prices; see our prices page for current comparisons.

What happened

Mounjaro was authorised by the MHRA for weight management in November 2023 and became widely available privately in the UK during 2024. It quickly became one of the most commonly used private weight loss treatments, partly because of its effectiveness in clinical trials and partly because its UK list price was relatively low compared with many other countries.

In mid-August 2025, Eli Lilly confirmed that it would increase the UK list price of Mounjaro KwikPens from 1 September 2025. Key points of the change were:

• It applied to the list price, which is the price pharmacies pay for supply outside negotiated NHS arrangements.
• It varied by strength. The highest strengths saw the largest rise, widely reported as around 170%. Lower strengths saw smaller, though still substantial, percentage increases.
• NHS prices were not changed. Lilly said its arrangements with the NHS were unaffected.

Because private providers set their own retail prices based on what they pay for the medicine, most passed on some or all of the increase, although timing and approach varied between providers.

For an overview of the medicine itself, see our Mounjaro hub and Mounjaro UK complete guide.

Timeline of key events

Why Mounjaro became so widely used privately

To understand why the price rise mattered so much, it helps to understand why so many people were using Mounjaro privately in the first place.

Strong trial results

In the SURMOUNT-1 trial, published in the New England Journal of Medicine in 2022, adults with obesity (without diabetes) who took tirzepatide lost on average about 15% to 21% of their body weight over 72 weeks, depending on the dose, compared with about 3% on placebo. The head-to-head SURMOUNT-5 trial later found greater average weight loss with tirzepatide than with semaglutide (Wegovy). These results made tirzepatide the most effective licensed weight loss medicine in the UK by average trial outcomes.

Limited NHS access

NHS access to weight loss medicines has always been narrower than the licensed population. Wegovy, recommended in NICE TA875, is mainly available through specialist weight management services, which have limited capacity and long waits in many areas. The NHS roll-out of Mounjaro under TA1026 is phased over several years. For many people who meet the licence criteria but not the NHS criteria, private treatment was the only route.

A relatively low launch price

Lilly itself said the original UK list price was set well below the European average. Combined with competition between online pharmacies, this made private Mounjaro comparatively accessible in the UK, which in turn meant a large number of people were exposed to the price change when it came.

Why Lilly raised the price

Eli Lilly gave several reasons for the change in its public statements:

1. The original UK price was set low. Lilly said it had agreed a UK list price significantly below the European average when Mounjaro launched, to avoid delays in NHS access.
2. Alignment with other countries. It said it was aligning the UK list price more consistently with other developed countries.
3. New clinical evidence. Lilly pointed to evidence supporting the value of Mounjaro, including data published since launch.

The announcement came at a time of strong political pressure in the United States for other wealthy countries to pay more for medicines, so that US prices could fall. Many news reports linked the UK price rise to this context. Lilly's stated rationale focused on international price alignment.

Reports at the time also discussed concerns about medicines bought at lower UK prices being exported to higher-priced markets, although the scale of this was not clear.

What it meant for NHS patients

For people prescribed Mounjaro through the NHS, nothing changed in what they paid: the standard NHS prescription charge in England (unless exempt), or nothing in Scotland, Wales and Northern Ireland.

However, NHS access remains limited. NICE TA1026, published in December 2024, recommends tirzepatide for adults with a BMI of at least 35 and at least one weight-related condition (with lower BMI thresholds for some ethnic groups). Because of the number of people potentially eligible, NHS England is phasing access. Its interim commissioning guidance prioritised, from June 2025, people with a BMI of 40 or more (adjusted for ethnicity) and at least four of five conditions: type 2 diabetes, high blood pressure, heart disease, obstructive sleep apnoea and abnormal blood fats. Later cohorts widen the criteria over subsequent years.

So, while the price rise did not affect NHS patients, it did not make NHS treatment easier to get. See Mounjaro on the NHS and private vs NHS weight loss treatment.

What it meant for private patients

Higher costs, especially at higher doses

The structure of the rise meant that people on the highest strengths faced the largest increases. Because most people step up through several doses over the first months of treatment, many faced rising costs both from the list-price change and from moving to higher strengths. Our guide to how weight loss injection pricing works explains how dose and price interact.

Supply pressure before the deadline

In the weeks before 1 September 2025, demand rose as people tried to secure supply at the old price. The Pharmaceutical Journal reported concerns about stockpiling, and Lilly warned against inappropriate stockpiling of medicines. Some patients reported difficulty obtaining their usual pens during this period. Some providers announced temporary price holds for existing patients, while others moved to the new prices quickly.

Warnings about illegal sellers

The General Pharmaceutical Council (GPhC) warned that people might turn to illegal online sellers to obtain weight loss medicines at lower cost after the price rises, and urged people to make sure any prescription medicines they get online come from a GPhC-registered pharmacy. The GPhC later reported a rise in concerns raised about weight management services, including stock shortages, unfulfilled orders, refund requests and inappropriate advertising of alternatives.

Reviewing treatment plans

Faced with higher costs, people's responses varied. Some continued unchanged. Others discussed with their prescriber whether to stay at a lower dose, switch to a different medicine, or plan to stop. These are clinical decisions, and the right choice depends on individual circumstances.

Options people discussed, and what the evidence says

The table below summarises options people commonly considered after the rise. None is right for everyone, and all should be discussed with a prescriber.

Staying at a lower dose

In SURMOUNT-1, all three maintenance doses of tirzepatide (5mg, 10mg and 15mg) produced substantial average weight loss over 72 weeks: roughly 15%, 20% and 21% respectively. That means some people achieve good results without reaching the top dose. However, whether staying at a lower dose is appropriate depends on your progress, health goals and side effects. Never change your dose without advice. See the Mounjaro dosing schedule.

Switching to Wegovy

Wegovy (semaglutide) is another weekly injection licensed for weight management. In the head-to-head SURMOUNT-5 trial, people on tirzepatide lost more weight on average (about 20%) than those on semaglutide (about 14%) over 72 weeks. Some people who switch may maintain their weight loss; others may not. There is no official dose conversion between the two, so your prescriber will choose a safe starting dose. See switching from Mounjaro to Wegovy and Mounjaro vs Wegovy.

Oral options

At the time of writing, the MHRA has authorised two GLP-1 tablets for weight management: the Wegovy tablet (oral semaglutide), approved in 2026, and Foundayo (orforglipron), approved in August 2026. Neither had completed NICE appraisal for NHS use at the time of writing. Their dosing, effectiveness and availability differ from Mounjaro, so check the MHRA and current SmPC and discuss them with a prescriber. See switching from injection to tablet.

Stopping

Stopping is a legitimate choice, but it is important to understand what tends to happen. In SURMOUNT-4, people who had taken tirzepatide for 36 weeks and were then switched to placebo regained a substantial proportion of the weight they had lost over the following year, whereas those who continued lost more. Planning with your prescriber, focusing on diet, protein, activity and strength training, and monitoring your weight can help. See weight regain after stopping and Mounjaro maintenance.

If you are considering starting Mounjaro now

For people thinking about Mounjaro for the first time after the price rise, a few points are worth considering alongside a prescriber's clinical assessment.

Check whether it is suitable. Mounjaro is licensed for adults with a BMI of 30 or more, or 27 to 30 with at least one weight-related condition, alongside a reduced-calorie diet and more physical activity. It is not suitable for everyone. A prescriber will check your history, including pancreatitis, gallbladder disease, pregnancy plans, diabetes medicines and eating disorders. See who can get weight loss injections.

Think about the whole journey. Treatment usually starts at 2.5mg and steps up every four weeks or more. Since prices often differ by strength, the cost after several months may be noticeably higher than at the start.

Plan for the long term. Because weight regain after stopping is common, consider how long you might stay on treatment and what you would do if circumstances change.

Know about contraception. The MHRA advises that tirzepatide may reduce the effectiveness of oral contraceptives in people who are overweight, and recommends a non-oral method or adding a barrier method for four weeks after starting and after each dose increase. See GLP-1s and contraception.

Compare services, not just prices. Consider what each regulated provider includes, how quickly you can reach a clinician and how clearly they explain costs.

Common misunderstandings

"The NHS price went up too." Lilly said NHS prices did not change. NHS patients continue to pay only the standard prescription charge, where it applies.

"All providers had to charge the same new price." The change was to the manufacturer's list price. Retail prices are set by individual providers and still vary.

"Lower doses are just as effective, so everyone should stay low." Lower maintenance doses can be effective for some people, but average weight loss in SURMOUNT-1 was greater at higher doses. The right dose is an individual clinical decision.

"Switching to Wegovy gives the same results." Some people do well after switching, but on average semaglutide produced less weight loss than tirzepatide in SURMOUNT-5.

Lessons from the price rise

The 2025 change highlighted a few things worth bearing in mind for anyone using a private weight loss medicine.

List prices can change

Manufacturers can change list prices, and private patients usually feel the effect. When planning treatment, it is sensible to allow for the possibility of future changes, for any medicine.

Long-term cost matters more than the starting price

Because GLP-1 medicines tend to work only while they are taken, the total cost over a year or more matters more than the price of a single month. Our guide to the long-term cost of GLP-1 treatment explains how to think about this.

Regulation protects you

The price rise brought a wave of advertising for alternatives and a risk of people turning to unregulated sources. Only obtain prescription medicines from a UK-registered pharmacy after a proper consultation. See fake weight loss jabs.

Transparency from providers is important

Good providers explained the changes clearly, gave notice and supported patients in making clinical decisions. When choosing a provider, consider how they communicate about price changes as well as the price itself. Our providers page and guide to choosing an online pharmacy can help.

What to do if cost is a concern now

If you are taking Mounjaro and cost is a worry:

1. Talk to your prescriber first. Explain your situation. They can discuss whether staying at your current dose, switching or stopping is safest for you.
2. Do not skip doses or stretch intervals without advice. Missing doses can lead to more side effects when you restart, and long gaps may mean restarting at a lower dose. See Mounjaro missed dose.
3. Do not share pens or try to draw extra doses. This risks infection and inaccurate dosing.
4. Avoid unregulated sellers. Check any pharmacy on the GPhC register.
5. Ask your GP about NHS eligibility. You may meet the criteria for a current or future cohort.
6. Compare total costs, not headline prices. Our prices page compares what regulated providers include.

When to speak to a professional

Speak to your prescriber, GP or pharmacist before changing your dose, switching medicine or stopping Mounjaro. If you have diabetes, also speak to your diabetes team, as other medicines may need adjusting.

Seek urgent medical help (NHS 111, or 999 in an emergency) if you experience:

• severe, persistent abdominal pain, possibly spreading to your back, with or without vomiting (possible pancreatitis)
• pain in the upper right abdomen, fever, or yellowing of the skin or eyes (possible gallbladder problems)
• persistent vomiting or diarrhoea with signs of dehydration
• swelling of the face, lips or throat, or difficulty breathing
• any unexpected or severe reaction after using a pen obtained from an unregulated source

Report suspected side effects, or suspected fake medicines, to the MHRA through the Yellow Card scheme.