Mounjaro vs Wegovy Side Effects UK | Cured Pharmacy

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Cheapest Mounjaro vs Wegovy Side Effects - UK Price

Compare side effects and get the cheapest UK price on Mounjaro from £124.99 with £20 off using code Weightlossnew.

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Pricing Disclaimer: Prices on some pages may not be up to date — the live pricing table below and pricing shown during consultation are official current prices and take precedence over any other figures on the site.

Mounjaro (Tirzepatide)
Weeks 1–4

2.5mg

1 pen • 4 Weeks

£145 £124.99

£31.25 / Per Week

Your starting dose – designed to help your body adjust gently to treatment

⭐ Future Orders at £145
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Mounjaro (Tirzepatide)
Weeks 5–8

5mg

1 pen • 4 Weeks

£179 £159.00

£39.75 / Per Week

First step up – builds on your progress as your body adapts to treatment

⭐ Future Orders at £179
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Mounjaro (Tirzepatide)
Weeks 9–12

7.5mg

1 pen • 4 Weeks

£220 £200.00

£50.00 / Per Week

Mid-range dose – for continued progression and enhanced results

⭐ Future Orders at £220
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Mounjaro (Tirzepatide)
Weeks 13–16

10mg

1 pen • 4 Weeks

£245 £225.00

£56.25 / Per Week

Higher strength dose – supports significant weight loss progress

⭐ Future Orders at £245
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Mounjaro (Tirzepatide)
Weeks 17–20

12.5mg

1 pen • 4 Weeks

£270 £250.00

£62.50 / Per Week

Advanced dose – for patients requiring stronger therapeutic effect

⭐ Future Orders at £270
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Mounjaro (Tirzepatide)
Weeks 21+

15mg

1 pen • 4 Weeks

£287 £267.00

£66.75 / Per Week

Maximum dose – the highest available strength for optimal results

⭐ Future Orders at £287
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Wegovy (Semaglutide)
Weeks 1–4

0.25mg

1 pen • 4 Weeks

£89 £69.00

£17.25 / Per Week

Your starting dose – eases your body into treatment with minimal side effects

⭐ Future Orders at £89
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Wegovy (Semaglutide)
Weeks 5–8

0.5mg

1 pen • 4 Weeks

£99 £79.00

£19.75 / Per Week

First step up – continues building tolerance for long-term success

⭐ Future Orders at £99
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Wegovy (Semaglutide)
Weeks 9–12

1mg

1 pen • 4 Weeks

£119 £99.00

£24.75 / Per Week

Mid-range dose – where most patients start seeing meaningful results

⭐ Future Orders at £119
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Wegovy (Semaglutide)
Weeks 13–16

1.7mg

1 pen • 4 Weeks

£169 £149.00

£37.25 / Per Week

Higher strength – supports accelerated weight loss progress

⭐ Future Orders at £169
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Wegovy (Semaglutide)
Weeks 17+

2.4mg

1 pen • 4 Weeks

£199 £179.00

£44.75 / Per Week

Maximum dose – the highest available strength for optimal weight management

⭐ Future Orders at £199
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Wegovy Oral Pill
Weeks 1–4

1.5mg

1 pen • 4 Weeks

£83.00 £63.00

£20.75 / Per Week

Your starting dose – eases your body into treatment with minimal side effects

⭐ Future Orders at £83.00
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Wegovy Oral Pill
Weeks 5–8

4mg

1 pen • 4 Weeks

£110.00 £90.00

£27.50 / Per Week

First step up – continues building tolerance for long-term success

⭐ Future Orders at £110.00
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Wegovy Oral Pill
Weeks 9–12

9mg

1 pen • 4 Weeks

£140.00 £120.00

£35.00 / Per Week

Mid-range dose – where most patients start seeing meaningful results

⭐ Future Orders at £140.00
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Wegovy Oral Pill
Weeks 13+

25mg

1 pen • 4 Weeks

£199.00 £179.00

£49.75 / Per Week

Maximum dose – the highest available strength for optimal weight management

⭐ Future Orders at £199.00
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Compare Mounjaro vs Wegovy Side Effects for New Users

Published on: June 03, 2026

Understanding mounjaro vs wegovy side effects uk profiles is essential before starting treatment. Both medications are highly effective GLP-1 receptor agonists licensed by the MHRA, but their side effect patterns differ in frequency, severity, and duration. Our UK clinical team has supported thousands of patients through their weight loss journey, and this guide draws on real-world experience alongside clinical trial data to help you make an informed choice.

Common Side Effects: Mounjaro vs Wegovy Comparison

Both Mounjaro (tirzepatide) and Wegovy (semaglutide) work by mimicking natural gut hormones that regulate appetite and blood sugar, which means they share similar gastrointestinal side effects [1]. The most frequently reported adverse events in clinical trials include nausea, diarrhoea, vomiting, constipation, and abdominal discomfort.

In the SURPASS-1 trial, nausea occurred in approximately 12-18% of Mounjaro patients depending on dose, with most cases classified as mild to moderate and resolving within the first 4-8 weeks [1]. The STEP trials showed comparable rates for Wegovy, with nausea affecting 20-44% of participants, particularly during dose escalation phases [2].

The key difference lies in tolerability patterns. Mounjaro's dual GIP/GLP-1 mechanism appears to produce a slightly gentler onset of gastrointestinal effects in many patients, though individual responses vary considerably. Our clinical team finds that patients who start on the lowest licensed dose and follow the gradual titration schedule experience fewer treatment discontinuations due to side effects.

Nausea and Gastrointestinal Effects: What to Expect

Nausea is the most commonly reported side effect for both medications, but understanding when and why it occurs helps patients manage it effectively. GLP-1 receptor agonists slow gastric emptying, which contributes to satiety but can also cause temporary digestive discomfort [3].

Most patients report that nausea is most pronounced in the 24-48 hours following their weekly injection, particularly during the first month of treatment or after dose increases. Clinical experience shows that eating smaller, more frequent meals and avoiding high-fat foods significantly reduces symptom severity.

Vomiting affects approximately 5-9% of Mounjaro users and 9-24% of Wegovy users in clinical trials, though these figures include all dose levels [1][2]. Severe gastrointestinal side effects requiring treatment discontinuation occur in fewer than 5% of patients on either medication when proper dose escalation protocols are followed.

Managing Digestive Side Effects

UK prescribers recommend several evidence-based strategies to minimise gastrointestinal discomfort. Staying well-hydrated, avoiding lying down immediately after eating, and choosing bland, low-fat foods during the initial weeks can substantially improve tolerability. If nausea persists beyond the first month or becomes severe, your prescriber may adjust your titration schedule or consider alternative treatments.

Anti-nausea medications are rarely necessary, but can be prescribed if symptoms significantly impact quality of life. Most patients find that side effects diminish markedly after 4-6 weeks as the body adapts to the medication.

Mounjaro vs Wegovy Side Effects: Frequency and Severity

Direct head-to-head trials comparing tirzepatide and semaglutide side effect profiles are limited, but cross-trial analysis provides useful insights. Both medications demonstrate similar safety profiles, with gastrointestinal effects being the primary concern in the first 8-12 weeks [4].

Mounjaro clinical trials reported treatment discontinuation rates of 4-7% due to adverse events across all doses, with gastrointestinal issues accounting for the majority [1]. Wegovy trials showed discontinuation rates of 4-7% in the STEP programme, suggesting comparable overall tolerability [2].

Injection site reactions occur in approximately 2-3% of patients on either medication and are typically mild, consisting of temporary redness or slight swelling. Serious adverse events are rare with both treatments when patients are appropriately screened and monitored by UK prescribers.

Individual Variation in Side Effects

Clinical experience demonstrates substantial individual variation in how patients respond to each medication. Some patients tolerate Mounjaro exceptionally well but experience persistent nausea with Wegovy, whilst others report the opposite pattern. Factors including baseline digestive health, eating habits, stress levels, and concurrent medications all influence side effect profiles.

Your UK prescriber will consider your complete medical history, previous medication responses, and individual risk factors when recommending the most appropriate treatment. Both medications require gradual dose escalation specifically designed to minimise side effects whilst optimising therapeutic benefit.

Side Effect Mounjaro (Tirzepatide) Wegovy (Semaglutide) Management Tips
Nausea 12-18% of patients 20-44% of patients Eat smaller meals, avoid high-fat foods
Diarrhoea 13-16% of patients 20-30% of patients Stay hydrated, adjust fibre intake
Vomiting 5-9% of patients 9-24% of patients Take with food, slow dose escalation
Constipation 6-8% of patients 11-24% of patients Increase water and fibre intake
Injection site reactions 2-3% of patients 2-3% of patients Rotate injection sites, apply ice if needed
Discontinuation rate 4-7% due to side effects 4-7% due to side effects Follow titration schedule carefully

Less Common but Important Side Effects to Know

Beyond gastrointestinal effects, both Mounjaro and Wegovy carry additional considerations that UK prescribers discuss during clinical assessment. Hypoglycaemia (low blood sugar) is uncommon in patients without diabetes but can occur, particularly if combined with other glucose-lowering medications [3].

Gallbladder-related events, including gallstones and cholecystitis, have been reported in clinical trials of both medications at rates slightly higher than placebo groups [1][2]. The absolute risk remains low (approximately 1-2% of patients), but rapid weight loss itself is an independent risk factor for gallstone formation.

Increased heart rate has been observed with both tirzepatide and semaglutide, typically an elevation of 2-10 beats per minute that remains clinically insignificant for most patients [4]. Those with pre-existing cardiovascular conditions require careful monitoring, which forms part of the ongoing clinical review process.

Contraindications and Safety Considerations

Both Mounjaro and Wegovy are contraindicated in patients with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2 [1][2]. UK prescribers screen for these conditions during the clinical assessment process before prescribing either medication.

Patients with a history of severe gastrointestinal disease, including gastroparesis or inflammatory bowel disease, may not be suitable candidates due to the medications' effects on gastric motility. Pregnant or breastfeeding women should not use either treatment, and effective contraception is recommended for women of childbearing potential.

Pancreatitis has been reported rarely with GLP-1 receptor agonists, though causality has not been definitively established [3]. Patients should be advised to seek immediate medical attention if they experience severe, persistent abdominal pain. Your UK prescriber will review your pancreatic health history before recommending treatment.

Drug Interactions and Concurrent Medications

Both medications can delay gastric emptying, which may affect the absorption of oral medications. Patients taking medications with narrow therapeutic windows, such as warfarin or levothyroxine, may require closer monitoring and dose adjustments. Your UK prescriber will review all current medications during your clinical assessment to identify potential interactions.

Insulin and sulfonylurea doses typically require reduction when starting either Mounjaro or Wegovy to prevent hypoglycaemia. This adjustment must be made by a qualified prescriber based on individual glucose monitoring and clinical response.

Making Your Choice: Clinical Factors Beyond Side Effects

Whilst side effect profiles are important, treatment selection should consider multiple factors including efficacy, cost, availability, and individual patient circumstances. In the SURMOUNT-1 trial, Mounjaro demonstrated average weight reductions of up to 22.5% at the highest dose over 72 weeks [1]. The STEP trials showed Wegovy achieving average reductions of approximately 14.9% over 68 weeks [2].

At Cured Pharmacy, Mounjaro is available from £124.99 following clinical assessment by a UK prescriber, whilst Wegovy starts from £135.00. Both treatments require ongoing clinical review to monitor efficacy, tolerability, and any emerging side effects. Your prescriber will work with you to identify the most appropriate option based on your medical history, weight loss goals, and budget.

Many patients find that starting with a lower-cost option and switching if side effects prove problematic offers a practical approach. Our UK clinical team provides ongoing support throughout your treatment journey, with the flexibility to adjust medications or doses as needed to optimise both results and tolerability.

Scientific References

  1. Rosenstock, J., et al. (2021). Efficacy and safety of a novel dual GIP and GLP-1 receptor agonist tirzepatide in patients with type 2 diabetes (SURPASS-1): a double-blind, randomised, phase 3 trial. The Lancet, 398(10295), 143-155. https://doi.org/10.1016/S0140-6736(21)01324-6 [accessed 13 August 2026]
  2. Wilding, J. P. H., et al. (2021). Once-Weekly Semaglutide in Adults with Overweight or Obesity. New England Journal of Medicine, 384(11), 989-1002. https://doi.org/10.1056/NEJMoa2032183 [accessed 13 August 2026]
  3. Nauck, M. A., et al. (2021). GLP-1 receptor agonists in the treatment of type 2 diabetes – state-of-the-art. Molecular Metabolism, 46, 101102. https://doi.org/10.1016/j.molmet.2020.101102 [accessed 13 August 2026]
  4. Jastreboff, A. M., et al. (2022). Tirzepatide Once Weekly for the Treatment of Obesity. New England Journal of Medicine, 387(3), 205-216. https://doi.org/10.1056/NEJMoa2206038 [accessed 13 August 2026]
  5. NHS. (2026). Tirzepatide: a medicine to manage type 2 diabetes and treat obesity. https://www.nhs.uk/medicines/tirzepatide/ Accessed 13 August 2026.
  6. NHS. (2026). Overweight and obesity in adults. https://www.nhs.uk/conditions/overweight-and-obesity/ Accessed 13 August 2026.
  7. NHS England. (2026). Weight management injections. https://www.england.nhs.uk/ourwork/prevention/obesity/medicines-for-obesity/weight-management-injections/ Accessed 13 August 2026.

Information on this page is for educational purposes only and is not medical advice. All prescription treatments require clinical assessment by a UK-registered prescriber. Always consult a qualified healthcare professional before starting any new medication. Side effect frequencies are based on clinical trial data and individual experiences may vary. If you experience severe or persistent side effects, contact your prescriber or seek immediate medical attention.

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"Brilliant. Lost 4 stone on mounjaro no side effects at all. Cured pharmacy are excellent. Always helpful pens sent out quickly always comes with needles and sterile wipes. If you want to go on GLP-1 go to cured pharmacy. So professional. Thank you cured pharmacy you changed my health and well being."

Ann-Marie

"I absolutely love this product, I have been using 2.5mg as maintenance dose and have managed to control my weight without any side effects and can still eat well balanced meals. The pharmacy is very efficient friendly and helpful I would not purchase from anywhere else."

Sacha W.

"So far I'm really impressed by my results it's crazy cause I'm not snacking like how I used to do and I see my face slimming down already and it's only been 2 and a half weeks. Can't wait to give my feedback in 5 months time thank you cured pharmacy."

Kimberly G.

"Mounjaro has corrected my hormonal weight gain during menopause. I am using it now to maintain that balance. The results for me have been exceptional!"

Jennifer

"Great really helps cure those nasty habits can't wait for my next mounjaro pen."

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Faq

Which has worse side effects, Mounjaro or Wegovy?
Clinical trials suggest similar overall tolerability, though Wegovy shows slightly higher rates of nausea and vomiting in some studies. Individual responses vary considerably, and many patients tolerate one medication better than the other based on personal factors.
How long do Mounjaro vs Wegovy side effects last?
Most gastrointestinal side effects peak during the first 4-8 weeks of treatment and diminish significantly as the body adapts. Side effects may temporarily increase after dose escalations but typically resolve within 1-2 weeks.
Can I switch from Wegovy to Mounjaro if I experience side effects?
Yes, switching between medications is possible under prescriber supervision. Your UK clinical team will assess your response to the first medication and determine appropriate starting doses if transitioning to an alternative treatment.
Are Mounjaro vs Wegovy side effects worse at higher doses?
Gastrointestinal side effects tend to be dose-dependent, which is why both medications use gradual titration schedules. Starting at the lowest dose and increasing slowly allows your body to adapt and minimises adverse events.
Do Mounjaro and Wegovy have the same contraindications?
Yes, both medications share similar contraindications including personal or family history of medullary thyroid carcinoma, multiple endocrine neoplasia syndrome type 2, and pregnancy. Your UK prescriber will screen for these conditions during clinical assessment.
What are the serious side effects of Mounjaro vs Wegovy?
Serious but rare side effects include pancreatitis, gallbladder disease, severe allergic reactions, and kidney problems. Both medications carry similar risk profiles, and UK prescribers monitor patients regularly to identify any concerning symptoms early.
Is nausea worse with Mounjaro or Wegovy for new users?
Clinical trial data suggests Wegovy may produce slightly higher nausea rates (20-44%) compared to Mounjaro (12-18%), though individual experiences vary widely. Following the prescribed titration schedule and dietary modifications significantly reduces nausea severity for both medications.
How do I know if my side effects are normal or require medical attention?
Mild to moderate nausea, diarrhoea, and digestive discomfort are expected in the first weeks. Seek immediate medical attention for severe persistent abdominal pain, signs of pancreatitis, allergic reactions, or symptoms of dehydration from persistent vomiting.
Which has fewer side effects in the UK - Mounjaro or Wegovy?
Both Mounjaro and Wegovy share similar side effects like nausea, vomiting, and diarrhoea, though individual tolerance varies. Clinical data suggests some patients find Mounjaro's dual-action mechanism easier to tolerate, but Cured Pharmacy's prescribers assess your medical history to recommend the most suitable option for you.
Do Mounjaro side effects differ from Wegovy side effects during the first month?
Both medications commonly cause gastrointestinal side effects in the first few weeks as your body adjusts to treatment. Mounjaro's starting dose of 2.5mg and Wegovy's 0.25mg are designed to minimise initial side effects, and Cured Pharmacy provides full titration guidance to help you transition smoothly between doses.
Can I switch from Wegovy to Mounjaro if I'm experiencing side effects?
Yes, many patients switch between Mounjaro and Wegovy if they experience intolerable side effects with one medication. Cured Pharmacy's UK-registered prescribers can review your treatment history and advise on a safe transition plan, including appropriate dosing to minimise any new side effects.
Are Mounjaro vs Wegovy side effects worse at higher doses in the UK?
Side effects can become more pronounced as doses increase with both Mounjaro and Wegovy, which is why gradual titration is essential. Cured Pharmacy ensures you follow the correct dose escalation schedule and provides ongoing support if you experience any side effects at higher maintenance doses.
How long do Mounjaro and Wegovy side effects typically last?
Most side effects from Mounjaro and Wegovy are temporary and typically improve within 2-4 weeks as your body adjusts to each new dose. If side effects persist or worsen, Cured Pharmacy's clinical team can adjust your treatment plan or recommend strategies to manage symptoms effectively.
Tarun Kumar, Prescribing Pharmacist

Medically reviewed by

Tarun Kumar, Prescribing Pharmacist (GPhC 2233073)

Reviewed on: June 03, 2026

Last reviewed: 13 August 2026

Last updated on 13 August 2026.

Review History

Our experts continually monitor new findings in health and medicine, and we update our articles when new information becomes available.

Why this page was updated on 13 August 2026

Content checked and updated as part of our periodic review, to ensure accuracy and currentness.

Current version (13 August 2026)

Edited by: The Editorial Team

Medically reviewed by:

Tarun Kumar, GPhC No. 2233073, Prescribing Pharmacist


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