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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Is 5mg Mounjaro Equivalent to Wegovy in the UK?
Mounjaro 5mg is approximately equivalent to Wegovy 0.5mg in terms of strength, though direct dose comparisons are approximate—individual response varies significantly. Both are prescription-only GLP-1 (or dual GIP/GLP-1) medications for weight management in UK adults. Understanding the dosing relationship, cost differences, and how to access each medication through NHS or private routes is essential when considering which option suits your circumstances best.
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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.
Mounjaro vs Wegovy: Dose Comparison and Cost in the UK
Approximate dose equivalence: Mounjaro 5mg is roughly equivalent to Wegovy 0.5mg, though these medications work differently—Mounjaro is a dual GIP and GLP-1 receptor agonist, while Wegovy is a GLP-1 agonist only. This difference means individual weight loss results vary even at supposedly equivalent doses.
UK private prescription costs (typical range): Mounjaro 5mg costs approximately £150–£180 per month through private online prescribing services. Wegovy 0.5mg typically costs £129–£160 per month. Prices vary by provider and dose progression. Both require a clinical assessment before prescription. The KwikPen device (Mounjaro) contains 4 doses; Wegovy pens also contain 4 doses. Actual out-of-pocket cost depends on your chosen provider and any subscription arrangements.
- Mounjaro starts at 2.5mg, escalates over 4-week intervals to a maximum of 15mg
- Wegovy starts at 0.25mg, escalates to a maximum of 2.4mg
- Neither medication is typically available through standard NHS prescription—access is through tier 3 specialist weight management services or private prescribing
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 vs Private Access: How to Get Mounjaro or Wegovy in the UK
NHS route: Both Mounjaro and Wegovy may be prescribed through NHS tier 3 specialist weight management services if you meet eligibility criteria (BMI ≥30, or BMI 27–29.9 with weight-related health conditions). However, NHS availability is extremely limited—waiting lists are often months to years depending on your region. Your GP can refer you to your local specialist service, but there is no assures of access or timeline.
Private route: Online UK-licensed prescribers can issue prescriptions for both medications following a brief clinical consultation (usually 10–15 minutes). You complete a health questionnaire, speak with a prescriber, and if approved, your prescription is sent to a GPhC-registered pharmacy for dispensing. This typically takes 24–48 hours. Private prescribing requires payment upfront—there is no NHS subsidy. Use our GLP-1 weight loss calculator to explore potential outcomes and help inform your decision between Mounjaro and Wegovy.
- 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 5mg Mounjaro the same strength as any Wegovy dose?
Approximately, yes. Mounjaro 5mg is roughly equivalent to Wegovy 0.5mg in potency, though direct comparisons are not exact because the medications use different mechanisms. Mounjaro is a dual GIP/GLP-1 agonist; Wegovy is GLP-1 only. Individual response varies, so equivalent doses may produce different results from person to person.
Why is Mounjaro sometimes more expensive than Wegovy?
Mounjaro is newer and manufactured by Eli Lilly; Wegovy is made by Novo Nordisk. Pricing differs between private providers based on procurement costs, profit margins, and competitive positioning. Some providers charge more for Mounjaro; others price them similarly. Always compare costs across multiple GPhC-registered services before committing.
Can I switch from Wegovy to Mounjaro on the NHS?
Possibly, but it depends on your specialist weight management service's formulary (which medications they stock) and individual clinical circumstances. Your NHS prescriber would manage any switch. Private-to-NHS or NHS-to-private switches require separate assessments and prescriptions from each service.
How long does it take to get Mounjaro or Wegovy privately in the UK?
Online consultation typically takes 24–48 hours from appointment to prescription issuance. Dispensing by the pharmacy may take a further 24–48 hours. Some urgent services offer same-day or next-day dispatch. NHS routes can involve months of waiting depending on regional specialist service capacity.
What happens if I cannot afford private Mounjaro or Wegovy costs?
Explore NHS referral through your GP to tier 3 services—though waiting lists are long. Some weight management charities and services offer reduced-cost or subsidised access programmes. Discuss financial concerns with your GP, who may signpost local support. MyWeightCheck's BMI calculator can help you understand your health status and guide conversations with your healthcare provider.
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.