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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What's the Wegovy Equivalent to Mounjaro 7.5mg in the UK?
Mounjaro 7.5mg and Wegovy are not directly equivalent because they work through different mechanisms—Mounjaro uses a dual GIP and GLP-1 pathway, whilst Wegovy is a GLP-1 agonist only. However, based on clinical outcomes and dose titration patterns, Mounjaro 7.5mg is approximately equivalent to Wegovy 1.7mg in terms of weight loss effect. Both are prescription-only medicines available in the UK through NHS specialist services or private online consultations. This guide explains the approximate equivalence, how to access each medication, and what you can expect to pay in the UK private market.
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Calculate Your BMI Instantly
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 Cost and Private Access for Wegovy and Mounjaro
Both Wegovy and Mounjaro are available in the UK through two main routes: NHS specialist weight management services and private prescription via online consultations.
Private prescription costs (approximate ranges):
- Mounjaro: £129–£250 per month depending on dose (each KwikPen contains 4 weeks of injections)
- Wegovy: £150–£320 per month depending on dose (each pen contains 4 weekly injections)
Costs vary between providers and may include consultation fees (typically £20–£50). Starting doses are cheaper than maintenance doses. Private prescription access usually involves an online clinical assessment with a UK-licensed prescriber, after which a GPhC-registered pharmacy dispenses the medication. Neither medication is available on the NHS without a specialist referral, and NHS waiting times can be substantial in many regions.
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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 and What to Expect
NHS route: Requires a GP referral to a tier 3 specialist weight management service. Assessment is free, but waiting lists are often months to years depending on your region. Once assessed and approved, treatment is free.
Private route: Book an online consultation (£20–£50), complete a health questionnaire, and speak with a UK-licensed prescriber. If approved, your prescription is sent to a GPhC-registered pharmacy for dispatch. The entire process typically takes 3–5 business days. Use our free GLP-1 weight loss calculator to estimate potential outcomes at different doses, and our BMI calculator to check your eligibility starting point.
- 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 Mounjaro 7.5mg exactly the same as Wegovy 1.7mg?
No—they're not exact equivalents because Mounjaro is a dual GIP/GLP-1 agonist whilst Wegovy is GLP-1 only. However, clinical practice suggests Mounjaro 7.5mg produces similar weight loss outcomes to Wegovy 1.7mg. A prescriber can advise which is most appropriate for you based on your individual health profile.
Why does Mounjaro cost less than Wegovy on average?
Mounjaro pricing is typically lower because it's newer to the UK market and Eli Lilly has competitive pricing. Wegovy is more established. Costs also depend on the specific provider, dose, and whether consultation fees are bundled. Always compare total costs across different providers.
Can I switch from Mounjaro 7.5mg to Wegovy during treatment?
Only under prescriber guidance. Switching between medications requires medical supervision because the mechanisms differ slightly and dose timing may need adjustment. Never switch without discussing it with your prescriber—they can advise the safest transition approach.
What's included in the private prescription cost?
Typically the prescription fee, clinical assessment, and the medication itself. Some providers bundle consultation into the medication cost; others charge separately (£20–£50 for consultation). Always confirm total cost upfront, as price advertised may not include all fees.
How long does it take to receive Mounjaro or Wegovy after going private?
Usually 3–5 business days from approval. You'll have an online consultation, then if approved, your prescription goes to a GPhC-registered pharmacy for packing and dispatch. Some providers offer next-day delivery for an additional fee. Check with your chosen provider for their specific timescale.
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.