Information page only. Free Muscle does not sell, supply, source or broker Mounjaro (tirzepatide), or anything described as a "Mounjaro pill". Mounjaro is a prescription-only medicine in the UK: it can be obtained lawfully only with a prescription from a qualified prescriber, dispensed by a registered pharmacy. Mounjaro is a registered trade mark of Eli Lilly, with which this site has no connection. Nothing on this page is medical advice or dosing guidance.

Key facts

• What it is: the brand name of tirzepatide, a once-weekly injected medicine that activates two gut hormone receptors, GIP and GLP-1.
• Licensed UK uses: type 2 diabetes (adults, and children aged 10 and over) and weight management in adults with a BMI of 30 kg/m² or more, or 27 to under 30 kg/m² with a weight-related condition.
• Form: injection only. The electronic medicines compendium lists the Mounjaro KwikPen (four doses per pen); the MHRA products database also lists UK licences for single-dose pens and vials. No tirzepatide tablet is authorised in the UK, the EU or the United States.
• NHS in England: access is phased in over up to 12 years. Since around June 2026, adults with a BMI of 35 or more and at least four of five listed conditions may qualify (lower for some ethnic groups), where a local service offers it.
• Evidence: in SURMOUNT-1, mean weight change over 72 weeks was minus 15.0% to minus 20.9% depending on dose, against minus 3.1% with placebo. In SURMOUNT-4, stopping led to substantial regain.
• Safety: gastrointestinal effects are the most common. In January 2026 the MHRA strengthened warnings about rare severe and fatal pancreatitis.
• Fakes: in February 2026 the MHRA warned that fake 15 mg pens had been dispensed by a UK pharmacy, and it has raided several illegal production sites since October 2025.

What is Mounjaro and how does it work?

Mounjaro contains tirzepatide, a long-acting peptide that acts on the glucose-dependent insulinotropic polypeptide (GIP) receptor and the glucagon-like peptide-1 (GLP-1) receptor. According to the UK Summary of Product Characteristics (SmPC), it increases insulin release when blood glucose is high, reduces glucagon, slows stomach emptying and targets receptors in brain areas involved in appetite (shown in animal studies). In studies, people reported feeling fuller, less hungry and having fewer food cravings. Its elimination half-life is about five days, which allows once-weekly use.

Who it is licensed for in the UK

The SmPC (text revised 29 August 2026) lists two indications:

• Type 2 diabetes that is not adequately controlled, in adults, adolescents and children aged 10 and over, alongside diet and exercise, either alone when metformin is unsuitable or added to other diabetes medicines.
• Weight management, including weight loss and weight maintenance, alongside a reduced-calorie diet and more physical activity, in adults with an initial BMI of 30 kg/m² or more, or 27 to under 30 kg/m² with at least one weight-related condition. Examples include high blood pressure, abnormal blood fats, obstructive sleep apnoea, cardiovascular disease, prediabetes and type 2 diabetes.

It is not licensed for weight management under 18. The SmPC reports trial results in obstructive sleep apnoea and in heart failure with preserved ejection fraction, but not as separate UK indications. The EU authorisation, granted on 15 September 2022, covers the same two uses.

Presentation

The presentation listed on the electronic medicines compendium (emc) is the Mounjaro KwikPen, a pre-filled pen holding four doses (approved by the MHRA in January 2024), in six strengths: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg and 15 mg per 0.6 ml dose. The MHRA products database also lists UK licences for single-dose pre-filled pens and for vials in the same six strengths, plus parallel-import licences for some packs. The prescriber decides the strength; this page does not reproduce the SmPC schedule.

What the clinical trials found

All the trials below were funded by Eli Lilly; results are group averages, not individual predictions. Figures are from the cited papers and can differ slightly from the SmPC's.

Weight management

SURMOUNT-1 (NEJM, 2022). 2,539 adults without diabetes and with a BMI of 30 or more, or 27 or more with a weight-related complication, received weekly tirzepatide 5 mg, 10 mg or 15 mg, or placebo, for 72 weeks. Mean weight change was minus 15.0%, minus 19.5% and minus 20.9%, against minus 3.1% with placebo; 85% to 91% of tirzepatide participants lost at least 5%, against 35% on placebo. Adverse events led 4.3% to 7.1% of tirzepatide participants to stop, against 2.6% on placebo.

SURMOUNT-4 (JAMA, 2024). 783 adults entered a 36-week open-label lead-in on tirzepatide. At week 36, 670 participants who had reached the maximum tolerated dose (mean weight loss 20.9%) were randomised to continue or switch to placebo for 52 weeks. From week 36 to week 88, weight changed by minus 5.5% with tirzepatide and plus 14.0% with placebo.

SURMOUNT-5 (NEJM, 2025). In this open-label trial, 751 adults with obesity and without type 2 diabetes received the maximum tolerated dose of tirzepatide (10 mg or 15 mg) or semaglutide (1.7 mg or 2.4 mg) for 72 weeks. Mean weight change was minus 20.2% with tirzepatide and minus 13.7% with semaglutide; waist circumference fell by 18.4 cm and 13.0 cm.

Type 2 diabetes

SURPASS-2 (NEJM, 2021). In this open-label 40-week trial, 1,879 people with type 2 diabetes received tirzepatide 5 mg, 10 mg or 15 mg, or semaglutide 1 mg. HbA1c fell by 2.01, 2.24 and 2.30 percentage points with tirzepatide and 1.86 with semaglutide. Body weight fell by an estimated 1.9 kg, 3.6 kg and 5.5 kg more with the three tirzepatide doses than with semaglutide. Serious adverse events were reported in 5% to 7% of tirzepatide patients and 3% of semaglutide patients.

SURPASS-CVOT (NEJM, 2025). 13,299 people with type 2 diabetes and atherosclerotic cardiovascular disease were randomised to tirzepatide (up to 15 mg) or dulaglutide 1.5 mg, a medicine already shown to reduce cardiovascular events. Cardiovascular death, heart attack or stroke occurred in 12.2% and 13.1% respectively (hazard ratio 0.92, 95.3% confidence interval 0.83 to 1.01): tirzepatide was non-inferior, but superiority was not shown.

Sleep apnoea and heart failure

SURMOUNT-OSA (NEJM, 2024) comprised two 52-week trials in adults with moderate to severe obstructive sleep apnoea and obesity. The apnoea-hypopnoea index fell by 25.3 and 29.3 events per hour with tirzepatide, against 5.3 and 5.5 with placebo.

SUMMIT (NEJM, 2025) randomised 731 adults with heart failure with preserved ejection fraction and a BMI of 30 or more. Over a median of 104 weeks, cardiovascular death or worsening heart failure occurred in 9.9% with tirzepatide and 15.3% with placebo (hazard ratio 0.62, 95% confidence interval 0.41 to 0.95). The difference came from fewer worsening heart failure events (8.0% against 14.2%); cardiovascular deaths were few in both groups (2.2% and 1.4%).

Side effects, warnings and who should not use it

The SmPC safety data come from 14 phase 3 studies in which 15,169 adults received tirzepatide. Gastrointestinal reactions were the most frequent, mostly mild or moderate and mainly during dose increases. The frequencies below are from the SmPC's Table 1 and vary between the diabetes, weight-management and cardiovascular trials.

• Very common (1 in 10 or more): nausea, diarrhoea, vomiting, constipation, abdominal pain, decreased appetite, fatigue, and low blood sugar when used with a sulphonylurea or insulin.
• Common (1 in 100 to under 1 in 10): hypersensitivity reactions, dizziness, low blood pressure, indigestion, bloating, burping, wind, reflux, gallstones, gallbladder inflammation, hair loss, injection site reactions, faster heart rate, and raised lipase, amylase and calcitonin.
• Uncommon (1 in 1,000 to under 1 in 100): acute pancreatitis, delayed stomach emptying, altered taste, abnormal skin sensations and injection site pain.
• Rare (post-marketing reports): anaphylaxis and angioedema.

Pancreatitis and other warnings

On 29 January 2026 the MHRA strengthened the product information for all GLP-1 and dual GLP-1/GIP medicines, including tirzepatide, after rare reports of necrotising and fatal pancreatitis. It had received 1,296 UK Yellow Card reports of pancreatitis associated with these medicines from 2007 to October 2025, 19 of them fatal. For context, the MHRA estimates that roughly 25.4 million packs were dispensed in the past five years, a figure that excludes most online-only pharmacies. The warning sign is severe, persistent abdominal pain that may spread to the back, sometimes with nausea and vomiting. The MHRA advises urgent medical attention, and treatment is not restarted if pancreatitis is confirmed. Tirzepatide has not been studied in people with a history of pancreatitis, and the SmPC and MHRA advise caution in this group.

The SmPC also warns about low blood sugar with a sulphonylurea or insulin; dehydration from vomiting or diarrhoea, which can worsen kidney function; severe gastrointestinal disease; temporary worsening of diabetic retinopathy; and pulmonary aspiration under general anaesthesia or deep sedation. Because it slows stomach emptying, the SmPC recommends monitoring oral medicines with a narrow therapeutic range, such as warfarin. The only contraindication is hypersensitivity to tirzepatide or an ingredient.

Pregnancy, contraception and breastfeeding

Tirzepatide should not be used in pregnancy, and the SmPC says to stop it at least one month before a planned pregnancy. Because it may reduce the effect of the contraceptive pill in people with obesity or overweight, the SmPC and MHRA advise a non-oral method, or adding a barrier method for four weeks after starting and after each dose increase. On breastfeeding, sources differ. The SmPC revised in August 2026 reports undetectable to very low levels in breast milk in a study of 11 women and says use could be considered. The NHS page (reviewed May 2026) and MHRA guidance (updated February 2026) say it should not be used while breastfeeding.

Suspected side effects, and any pen that may be fake or faulty, can be reported through the MHRA Yellow Card scheme.

Can you get Mounjaro on the NHS?

England: weight management

NICE TA1026 (published 23 December 2024, updated 1 September 2025) recommends tirzepatide for adults with an initial BMI of at least 35 kg/m² and at least one weight-related comorbidity. The threshold is usually 2.5 kg/m² lower for people of South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean background. If less than 5% of initial weight has been lost after six months on the highest tolerated dose, a decision is made on whether to continue.

Because the eligible population is so large (NICE estimates 3.4 million people), NICE has allowed a maximum implementation period of 12 years. NHS England's interim commissioning guidance sets out who may be eligible during the first three years, in which NICE expects at least 220,000 people to be funded. Eligibility in this period depends on BMI and on five qualifying conditions: high blood pressure, dyslipidaemia, obstructive sleep apnoea, cardiovascular disease and type 2 diabetes.

Phase	From	Who becomes eligible
Cohort 1	June 2025	BMI 40 or more and at least 4 of the 5 conditions
Cohort 2	Around June 2026	BMI 35 to 39.9 and at least 4 of the 5 conditions
Cohort 3	Around March to April 2027	BMI 40 or more and 3 of the 5 conditions

These BMI thresholds are 2.5 kg/m² lower for the ethnic groups above. Since 1 April 2026, tirzepatide prescribing for weight management has been part of the GP contract, but practices are not required to take part. Specialist weight management services can also prescribe it, and NHS Cheshire and Merseyside notes that meeting the criteria does not guarantee treatment. NICE quality standard QS212 expects people prescribed weight-management medicines to receive wraparound support on diet, nutrition and physical activity.

England: type 2 diabetes

NICE TA924 (published 25 October 2023) recommends tirzepatide when triple therapy with metformin and two other oral medicines is ineffective, not tolerated or contraindicated, together with BMI-based criteria. The updated diabetes guideline NG28 (18 February 2026) allows it to be considered earlier for some people: alongside metformin and an SGLT-2 inhibitor in early-onset type 2 diabetes, or as an add-on for adults living with obesity who need further glucose lowering after at least three months of initial therapy. NICE says work is ongoing to align TA924 with NG28.

Scotland, Wales and Northern Ireland

Scotland: the Scottish Medicines Consortium accepted tirzepatide for restricted use for weight management in adults with a BMI of 30 kg/m² or more and at least one weight-related comorbidity (SMC2653, June 2024). It also accepted it for type 2 diabetes as an add-on where a GLP-1 medicine would be considered (SMC2633, April 2024).

Wales: under Welsh Health Circular WHC/2025/043 (updated 7 July 2026), until a new clinical pathway is in place, tirzepatide for weight loss should be prescribed in the NHS in Wales only through specialist weight management services. There are two exceptions. The first covers people with a BMI of at least 35 kg/m² (lower for some ethnic groups), a weight-related comorbidity and an urgent clinical need, when the service treating that condition prescribes. Examples include time-sensitive surgery, an organ transplant, fertility treatment, severe sleep apnoea and obesity hypoventilation syndrome. The second is prescribing within an approved proposal under the obesity pathway innovation programme.

Northern Ireland: in June 2025 the Department of Health endorsed TA1026 as applicable, and the Strategic Planning and Performance Group's service notification said no services were yet commissioned to support prescribing for obesity. On 29 June 2026 the Department said its new Regional Obesity Management Service was expected to start in early autumn 2026, with phase one for adults with a BMI above 45 and at least one of five listed conditions.

Prescription charges: in England, NHS prescriptions cost £9.90 per item for those not exempt; prescriptions are free in Scotland, Wales and Northern Ireland.

Private prescriptions: how lawful supply works

Under the Human Medicines Regulations 2012, a prescription-only medicine may be sold or supplied only under a prescription from an appropriate practitioner (regulation 214), and no one may publish an advertisement likely to lead to its use (regulation 284). The NHS says a private supply should come from a registered pharmacy, because some websites sell fake weight-loss medicines. The General Pharmaceutical Council (GPhC) expects a consultation for weight-management medicines to include:

• two-way communication with the prescriber, not an online questionnaire alone;
• independent verification of weight, height or BMI, for example by video, in person or from clinical records;
• attention to wellbeing, since eating disorders, body dysmorphia and mental health problems can lie behind a request;
• ongoing monitoring and advice on side effects.

The MHRA advises checking that a pharmacy in Great Britain is on the GPhC register, or, in Northern Ireland, registered with the Pharmaceutical Society of Northern Ireland. It warns against beauty salons, social media sellers and anyone who skips a consultation. On 2 October 2026 it named nine weight-loss providers that amended their advertising after MHRA action on complaints.

Cost: what public sources report

This site gives no price because it does not supply Mounjaro. NICE lists the manufacturer's four-week prices, excluding VAT, as £133.00 (2.5 mg), £180.00 (5 mg), £255.00 (7.5 mg and 10 mg) and £330.00 (12.5 mg and 15 mg), after a price list update on 1 September 2025. The NHS pays under a confidential commercial arrangement; private clinic charges are not covered by these sources.

Fake and unlicensed Mounjaro

On 24 February 2026 the MHRA reported that fake Mounjaro KwikPen 15 mg pens had been dispensed by one pharmacy in Birmingham. They carried batch number D873576, which belongs to a genuine 7.5 mg batch, and came to light after faults such as the dose knob coming off. They contained tirzepatide, but their sterility could not be confirmed, and the GPhC placed conditions on the pharmacy. The MHRA's Criminal Enforcement Unit has also raided illegal manufacturing sites:

• October 2025, Northampton: the first illicit weight-loss medicine production site found in the UK, with more than 2,000 unlicensed retatrutide and tirzepatide pens seized.
• February 2026, Lincolnshire and Nottinghamshire: almost 2,000 doses seized at two premises.
• 28 May 2026, near Northampton: two arrests and around 12,000 doses recovered, the agency's largest ever seizure of such products.

The MHRA says illegally sold products may not contain the expected medicine and may be contaminated with bacteria or other harmful substances. It has also warned that retatrutide, a GLP-1 medicine still in clinical development, is not authorised in the UK and that anyone selling it does so illegally. Its rule: if a GLP-1 medicine is available without a prescription, walk away.

Stopping Mounjaro and keeping weight off

In SURMOUNT-4, 89.5% of those who stayed on tirzepatide kept at least 80% of their earlier weight loss at week 88, against 16.6% of those switched to placebo, and the authors concluded that withdrawal led to substantial regain. The NHS advises talking to a doctor before stopping and not stopping suddenly; for people with type 2 diabetes, stopping could affect blood sugar. NICE QS212 expects people stopping weight-management medicines to receive advice on maintaining changes and on where to find support.

Mounjaro compared with other GLP-1 medicines

In the head-to-head trials described above, tirzepatide lowered HbA1c and body weight more than semaglutide 1 mg, an Ozempic strength (SURPASS-2), and lowered weight more than semaglutide 1.7 mg or 2.4 mg, Wegovy strengths (SURMOUNT-5). The MHRA advises against switching between GLP-1 medicines, even brands of the same substance, without medical advice.

Brand	Active substance and form	Main UK licensed use
Mounjaro	Tirzepatide (GIP and GLP-1), weekly injection	Type 2 diabetes; weight management
Ozempic	Semaglutide, weekly injection	Type 2 diabetes
Rybelsus	Semaglutide, daily tablet	Type 2 diabetes
Wegovy	Semaglutide, weekly injection; daily tablet approved 11 June 2026	Weight management; the injection is also licensed to reduce cardiovascular risk in some adults
Foundayo	Orforglipron, daily tablet, authorised 10 August 2026	Weight management; type 2 diabetes
Saxenda, Nevolat, BIOLIDE	Liraglutide, injection	Weight management

When approving the Wegovy tablet and Foundayo, the MHRA said neither was yet available on the NHS and that NHS use would follow NICE evaluation.

Is there a Mounjaro pill?

No. When checked on 5 October 2026, every tirzepatide product listed by the MHRA (pens or vials), the EMA and the US FDA (Mounjaro and Zepbound) was an injection. The GLP-1 tablets authorised in the UK, the EU or the US contain semaglutide or orforglipron, not tirzepatide, so anything sold as "Mounjaro pills" is not Mounjaro. See our page on Mounjaro pills and oral GLP-1 medicines.

Frequently asked questions

Can Mounjaro be sold or supplied without a prescription in the UK?

Not lawfully. Any seller offering Mounjaro without a prescription is acting unlawfully (regulation 214). The MHRA says products sold this way may be fake or contaminated, and advises checking that an online pharmacy is registered with the GPhC (or, in Northern Ireland, the Pharmaceutical Society of Northern Ireland).

Can my GP prescribe Mounjaro for weight loss?

Possibly, if you fall within the currently eligible NHS England cohort and your practice provides the service. NHS Cheshire and Merseyside adds that a GP should know about tirzepatide use even when it is prescribed privately. Wales and Northern Ireland differ (see above).

How much weight do people lose on Mounjaro?

Results vary widely. In SURMOUNT-1, 50% of participants on 10 mg and 57% on 15 mg lost 20% or more of their body weight over 72 weeks, against 3% on placebo. The SmPC adds that a body-composition sub-study suggested most of the weight lost was fat tissue, including visceral fat.

Can you drink alcohol while using Mounjaro?

The NHS says it is best to avoid alcohol, because it can make side effects such as nausea and vomiting worse.

Should I mention Mounjaro before an operation or sedation?

Yes. The MHRA asks people on GLP-1 or dual GIP/GLP-1 medicines to tell their healthcare team, including the anaesthetist, before a procedure. Its January 2025 safety update on pulmonary aspiration also warns anaesthetists that private prescriptions may not always appear in a patient's medical notes or drug history.

Does Mounjaro cause hair loss?

It can. In pooled SURMOUNT-1, 2 and 3 data, hair loss was reported by 4.9% on tirzepatide and 1.0% on placebo; the SmPC says it was mainly mild and most people recovered while continuing.

Does Mounjaro affect mood?

After a comprehensive review, the MHRA concluded that the available data do not support a causal link between GLP-1 medicines and depression, suicidal thoughts or suicide, and it continues to monitor for severe psychiatric reactions.

Is Zepbound the same as Mounjaro?

Both contain tirzepatide and are made by Eli Lilly. Zepbound is the US brand for weight management and for moderate to severe obstructive sleep apnoea in adults with obesity. It is not authorised in the UK, where every tirzepatide licence on the MHRA products database is for Mounjaro. The US Mounjaro label also covers reducing major cardiovascular events in high-risk adults with type 2 diabetes.

What should I do if I think my pen is fake?

The MHRA asks anyone who suspects a counterfeit or faulty weight-loss pen to report it through the Yellow Card scheme. Anyone with signs of infection (redness, swelling, warmth or pain at the injection site, or fever) or an allergic reaction should seek urgent medical attention.

Related pages

• Mounjaro pills: oral GLP-1 medicines explained (English)
• Mounjaro (tirzepatidă): informații generale (Romanian)
• Mounjaro pastile: ce există și ce nu (Romanian)

Sources

All sources were checked on 5 October 2026.

1. emc: Mounjaro KwikPen SmPC (text revised 29 August 2026); tirzepatide search; SmPCs for Ozempic, Rybelsus and Wegovy. MHRA Products: tirzepatide licences and SmPCs (single-dose pens, KwikPens and vials, SmPCs dated 4 September 2026, and parallel-import licences).
2. European Medicines Agency: Mounjaro EPAR (overview updated 18 August 2026); secondary: EMA medicines data (machine-readable JSON), listing one authorised tirzepatide medicine.
3. NICE: TA1026, with recommendations and list prices and implementation (12-year maximum period, 3.4 million eligible, at least 220,000 in the first three years); TA924; NG28 initial medicines and further medication; QS212 statement 6 and statement 7.
4. NHS Cheshire and Merseyside: Tirzepatide (Mounjaro) for obesity (updated 2 April 2026).
5. Scottish Medicines Consortium: SMC2653; SMC2633.
6. Wales and Northern Ireland: Welsh Government, New clinical pathway for treating and managing obesity (WHC/2025/043) (updated 7 July 2026); Strategic Planning and Performance Group, service notification for TA1026 (6 June 2025); Department of Health (NI), first phase of the Regional Obesity Management Service (29 June 2026).
7. NHS: Tirzepatide (reviewed 15 May 2026); prescription charges. NHS Business Services Authority: help with NHS prescription costs (prescriptions free in Scotland and Wales). nidirect: help with health costs (prescriptions free in Northern Ireland).
8. SURMOUNT-1: Jastreboff AM, et al. N Engl J Med 2022;387:205 to 216. PubMed 35658024.
9. SURMOUNT-4: Aronne LJ, et al. JAMA 2024;331:38 to 48. PubMed 38078870.
10. SURMOUNT-5: Aronne LJ, et al. N Engl J Med 2025;393:26 to 36. PubMed 40353578.
11. SURPASS-2: Frías JP, et al. N Engl J Med 2021;385:503 to 515. PubMed 34170647.
12. SURPASS-CVOT: Nicholls SJ, et al. N Engl J Med 2025;393:2409 to 2420. PubMed 41406444.
13. SURMOUNT-OSA: Malhotra A, et al. N Engl J Med 2024;391:1193 to 1205. PubMed 38912654.
14. SUMMIT: Packer M, et al. N Engl J Med 2025;392:427 to 437. PubMed 39555826.
15. MHRA safety: pancreatitis Drug Safety Update and press release (29 January 2026); pulmonary aspiration Drug Safety Update (28 January 2025); GLP-1 medicines: what you need to know (updated 5 February 2026).
16. MHRA fakes and enforcement: fake Mounjaro KwikPen 15mg pens (24 February 2026); raids of 24 October 2025 (which also describes retatrutide as in clinical development), 25 February 2026 and 29 May 2026; No summer shortcut for safe weight loss (24 July 2026); advertising investigations, September 2026 (2 October 2026).
17. MHRA approvals: Mounjaro KwikPen (25 January 2024); Wegovy tablet (11 June 2026); orforglipron (Foundayo) (10 August 2026).
18. General Pharmaceutical Council: weight loss medications FAQ (lists Saxenda, Nevolat and BIOLIDE as liraglutide injections licensed for weight loss); pharmacy register. MHRA: Yellow Card; #FakeMeds.
19. Human Medicines Regulations 2012: regulation 214 and regulation 284.
20. US FDA, Drugs@FDA: Mounjaro (NDA 215866), Zepbound (NDA 217806) and Foundayo (NDA 220934). DailyMed: Mounjaro US prescribing information (updated 27 August 2026). Secondary: openFDA tirzepatide data (machine-readable JSON), listing only Mounjaro and Zepbound.

General information only, not medical advice; questions about Mounjaro should go to a GP, pharmacist or prescriber. Free Muscle does not sell, supply, source or broker Mounjaro or tirzepatide. Mounjaro is a registered trade mark of Eli Lilly, with which this site has no connection. Facts checked on 5 October 2026.