The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
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Managing Nausea With Mounjaro in the UK
Nausea is one of the most common side effects when starting Mounjaro (tirzepatide), especially during the initial dose escalation phase. If you're experiencing nausea and considering or currently taking this prescription weight loss injection, understanding your access options and costs in the UK can help you make informed decisions about continuing treatment. This guide covers NHS eligibility, private prescription routes, and practical management strategies for Mounjaro-related nausea.
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Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
UK Private Access and Cost Context for Mounjaro
In the UK, Mounjaro is available through two routes: NHS specialist services and private online prescribing. Private prescription costs for Mounjaro vary depending on the dose and provider, typically ranging from £129 to £320+ per month. The KwikPen device contains four weekly doses, so monthly costs reflect the dose level you're on — starting doses (2.5 mg) are generally less expensive than maintenance doses (15 mg). When accessing Mounjaro privately, you'll need a consultation with a UK-licensed prescriber who will assess your eligibility based on your BMI and weight-related health conditions. Private prescriptions are then dispensed by GPhC-registered pharmacies. Cost can be a significant consideration when managing side effects like nausea — some people find adjusting their dose titration schedule or trying additional medications to manage nausea helpful, both of which require prescriber input.
- Private doses range from 2.5 mg to 15 mg weekly
- Costs typically £129–£320+ per month depending on dose
- Each KwikPen contains 4 weeks of doses
- Prescriptions issued following online clinical assessment
- Dispensed by regulated UK pharmacies only
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How It Works
Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
Free Weight Loss Tools & Guides
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NHS Route and Managing Nausea Long-Term
Access to Mounjaro on the NHS is through specialist tier 3 weight management services, typically following a GP referral. NHS availability varies significantly by region and ICB (Integrated Care Board), and waiting lists can extend several months or longer in some areas. If you're on the NHS route and experiencing significant nausea, your specialist team can adjust your dose escalation pace — slowing the titration schedule sometimes helps reduce nausea severity. They may also recommend anti-nausea medications or dietary adjustments. Importantly, nausea often improves naturally as your body adjusts, particularly after the first 4–8 weeks. If nausea is severe enough to affect your quality of life, discussing this with your prescriber (NHS or private) is essential — there are management strategies, and stopping the medication is always an option if the side effect outweighs benefits.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs range from approximately £129 to £320+ per month, depending on your dose level. Starting doses (2.5–5 mg) cost less than higher maintenance doses (10–15 mg). Each KwikPen provides four weekly injections. Prices vary slightly between providers, so it's worth comparing. Always ensure you're using a GPhC-registered pharmacy.
Can I get Mounjaro free on the NHS?
Yes, Mounjaro is available on the NHS through specialist tier 3 weight management services, typically after a GP referral. However, availability and waiting times vary significantly by region. Some areas have long waiting lists. Your GP can tell you whether your local ICB offers NHS access and what the current wait time is.
How long does nausea last when starting Mounjaro?
Nausea is very common during the first 4–8 weeks, particularly when starting or increasing doses. For many people, it improves as the body adjusts. If nausea persists beyond 8 weeks or is severe, discuss this with your prescriber — they may adjust your dose escalation schedule, recommend anti-nausea strategies, or suggest you switch to Wegovy (semaglutide), which some people tolerate better.
Is nausea with Mounjaro the same as with Wegovy?
Nausea is common with both Mounjaro (tirzepatide) and Wegovy (semaglutide), though individual experiences vary. Some people find Mounjaro's dual GIP/GLP-1 mechanism causes more nausea initially, while others tolerate it better than Wegovy. Your prescriber can help determine which might suit you if you're deciding between the two.
What can I do to manage Mounjaro nausea without stopping treatment?
Strategies include eating smaller, frequent meals; avoiding fatty or greasy foods; staying hydrated; ginger supplements; and anti-nausea medications like metoclopramide (prescribed by your GP). Slowing your dose escalation with your prescriber can also help. Use our GLP-1 weight loss calculator to understand whether continuing is worth the short-term discomfort for your projected outcomes.
Ready to take control of your weight loss journey?
Start with a free BMI check, explore your GLP-1 options, or begin tracking your progress today. No sign-up. No cost. Just results.