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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1mg Wegovy Compared to Mounjaro in the UK
Comparing 1mg Wegovy to Mounjaro? Both are prescription-only GLP-1 weight management injections available in the UK, but they differ in cost, access, and how they work. At 1mg dose, Wegovy is still in the dose escalation phase, whilst Mounjaro at equivalent doses offers a dual GIP and GLP-1 mechanism. This guide explains UK pricing, how to access each medication, and what determines which might be suitable for you. Both require a clinical assessment before prescription.
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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 Cost & Access for Wegovy vs Mounjaro
1mg Wegovy cost in the UK: Private prescriptions for Wegovy at 1mg typically cost between £129–£160 per month through UK-registered online pharmacies, depending on the provider. At this dose, you're in weeks 5–8 of the dose escalation schedule.
Mounjaro 5mg cost in the UK: The approximate equivalent Mounjaro dose (5mg) generally costs £150–£190 per month privately. Mounjaro's dual mechanism (GIP + GLP-1 agonist, not just GLP-1 like Wegovy) may differentiate outcomes, though individual results vary significantly.
- Both require a valid UK prescription from a licensed prescriber
- Private access does not require NHS referral or waiting lists
- Prices vary by provider and may include consultation fees
- Online consultations typically cost £30–£80 separately, though some providers bundle this
Cost comparison alone shouldn't determine choice — prescriber assessment of your individual health profile is essential.
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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
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
NHS vs Private Access — How to Get Each
NHS route: Both Wegovy and Mounjaro are available through NHS specialist tier 3 weight management services, but only after GP referral. Access is severely limited by regional availability and waiting lists can extend many months. NICE has approved tirzepatide (Mounjaro) for NHS use, but availability depends on your integrated care board (ICB).
Private route: You can access either medication through a UK online consultation with a licensed prescriber without NHS referral. The process typically takes 1–3 days: complete a health questionnaire, have a video consultation, receive a prescription if clinically appropriate, and collect from a GPhC-registered pharmacy. Use our free GLP-1 weight loss calculator to explore potential outcomes with different doses before you consult.
- 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.
Is 1mg Wegovy the same strength as 5mg Mounjaro?
No — these are different medications with different mechanisms. 1mg Wegovy is a GLP-1 agonist only. 5mg Mounjaro is a dual GIP and GLP-1 agonist. Approximate dose equivalence doesn't mean identical effect. Clinical trials show different average weight loss profiles, and individual results vary. Your prescriber will advise which is appropriate for you.
Which is cheaper — 1mg Wegovy or Mounjaro?
Prices vary by private provider, but 1mg Wegovy typically costs slightly less (£129–£160/month) than equivalent Mounjaro doses (£150–£190/month). However, prices change and differ between pharmacies. NHS access eliminates cost but involves referral, assessment, and waiting lists. Always compare current quotes from multiple licensed providers.
Can I switch from Wegovy to Mounjaro in the UK?
Yes, you can switch between medications with prescriber guidance. Any switch must be managed by your prescriber — there's no automatic conversion process. You'll need a new assessment, new prescription, and adjustment period on the new medication. Discuss with your prescriber if you're considering a change.
How long does it take to get Wegovy or Mounjaro privately in the UK?
Private access is typically faster than NHS. Online consultations usually take 1–3 days from questionnaire to prescription. NHS referral to specialist services can take 3–12 months depending on your region. If approved privately, collection from pharmacy is usually within 1–2 weeks.
Do I need NHS approval to get 1mg Wegovy or Mounjaro privately?
No. Private prescriptions are independent of NHS. You can access either medication through a private online consultation without NHS referral. However, you must still meet clinical eligibility criteria and have a consultation with a UK-licensed prescriber before a prescription is issued.
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.