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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Nausea and Mounjaro — Understanding Cost and UK Access
Nausea is one of the most common side effects when starting Mounjaro (tirzepatide), particularly during the first few weeks of treatment. If you're considering Mounjaro in the UK and concerned about nausea or how to access the medication, you'll want to understand both the cost implications and whether it's available through the NHS or private prescribing. This guide explains the realistic costs of Mounjaro in the UK and the different routes to accessing it, so you can make an informed decision about whether this weight management injection is right for you.
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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.
Mounjaro Cost and Private Access in the UK
In the UK, Mounjaro (tirzepatide) is available through two main routes: NHS specialist services and private online prescribing. Private costs typically range from £129 to £320 per month, depending on your dose and the prescribing provider. A standard 4-week supply (one KwikPen containing four doses) costs roughly £150–£250 privately. The most commonly prescribed maintenance doses—10 mg and 15 mg—sit at the higher end of this range. Costs increase as you progress through the dose titration schedule, starting from 2.5 mg and escalating every 4 weeks.
When you access Mounjaro privately, you'll typically pay an online consultation fee (£20–£50) plus the medication cost. Some providers offer subscription models where the consultation is included. It's worth comparing providers, as costs and added services vary. Always use a GPhC-registered pharmacy to ensure the prescription is legitimate and the medication is genuine.
- Monthly cost varies by dose: lower doses (2.5–5 mg) may be slightly cheaper
- Budget approximately £150–£250 per month for most doses
- Online consultations add £20–£50 to initial costs
- Prescriptions typically valid for 28 days—exact timing depends on your provider
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
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
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
NHS Access vs Private Prescribing Routes
NHS Access: Mounjaro is now approved by NICE for use within NHS tier 3 specialist weight management services. However, NHS access is not available through standard GP prescription—you must be referred to a specialist weight management service. Waiting times vary dramatically by region (ICB area) and can range from several months to over a year in some areas. Once initiated through NHS specialist services, the medication is provided free on prescription.
Private Route: You can access Mounjaro immediately without NHS referral through a licensed online prescriber and GPhC-registered pharmacy. The process takes 24–48 hours: complete an online health questionnaire, have a consultation with a UK-licensed prescriber (usually a doctor or pharmacist), receive your prescription, and collect from a registered pharmacy. This route suits those who don't want to wait for NHS services or have already been assessed and declined by NHS services. Individual clinical assessment is required regardless of route—no prescriber will issue Mounjaro without confirming eligibility.
- 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.
Does nausea from Mounjaro go away over time?
Yes, for most people. Clinical data shows nausea is most severe in the first 2–4 weeks but typically improves as your body adapts. By week 8–12, many patients report nausea has reduced significantly or resolved. Eating smaller, bland meals and staying hydrated can help. If nausea persists beyond 12 weeks, contact your prescriber—dose adjustment may be needed.
What's the cheapest way to get Mounjaro in the UK?
The cheapest long-term option is NHS prescription through a specialist weight management service, where it's free on prescription. However, waiting times can be long. Privately, costs are typically £150–£250 per month. Comparing GPhC-registered pharmacies can save £20–£50—some offer loyalty discounts or subscription pricing. Always verify the pharmacy is registered.
Can my GP prescribe Mounjaro on the NHS?
No. Standard GP prescription of Mounjaro is not currently available in most areas. You must be referred to a tier 3 specialist weight management service through your GP. This service then assesses your eligibility and prescribes Mounjaro if appropriate. Ask your GP for a referral if you're interested in NHS access.
How long does it take to get Mounjaro privately in the UK?
The private route is much faster than NHS. Most online prescribers complete assessment and issue a prescription within 24–48 hours. You can collect your first dose within 2–3 days. Compare this to NHS waiting times, which can be several months to a year in many areas.
Is Mounjaro more expensive than Wegovy in the UK?
Costs are generally comparable—both typically range from £150–£250 per month through private providers. Wegovy (semaglutide) and Mounjaro (tirzepatide) are similar in cost structure. The key difference is clinical: Mounjaro is a dual GIP/GLP-1 agonist while Wegovy is GLP-1 only. Individual trial results also vary. Your prescriber can advise which is more suitable based on your health profile.
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.