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
Free tracker included with every download this week
What's the 5mg Mounjaro to Wegovy Equivalent in the UK?
Many people wonder how Mounjaro and Wegovy doses compare, and whether one is more affordable or accessible than the other. At 5mg, Mounjaro is roughly equivalent to 0.5mg Wegovy in terms of strength, though the two medications work through slightly different mechanisms. This guide explains the approximate dose equivalence, compares costs across private prescription routes in the UK, and shows you how to access both medications through NHS specialist services or private online consultations.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 5mg vs Wegovy — Approximate Equivalence and Cost Context
Approximate dose equivalence: Mounjaro 5mg is roughly equivalent to Wegovy 0.5mg, though direct comparison has important limits. Mounjaro is a dual GIP and GLP-1 receptor agonist, while Wegovy (semaglutide) is a GLP-1 agonist only — so they don't work identically even at similar potencies. Clinical trial data shows Mounjaro 5mg produces average weight loss of around 15% body weight, while Wegovy at 0.5mg produces more modest results as it's an escalation dose, not maintenance.
Cost differences: Private prescription costs in the UK vary by provider and dose. Mounjaro at 5mg typically costs £180–£240 per month through private online prescribing services. Wegovy costs vary similarly, around £140–£200 monthly depending on dose and provider. Neither medication is cheaper than the other across all providers — prices depend on the specific service, stock levels, and any promotional pricing. Always compare costs across GPhC-registered pharmacies before committing.
Remember: individual results vary significantly, and cost alone should not determine which medication is right for you. Your prescriber will assess your individual health profile and recommend the most suitable option.
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.
Accessing Mounjaro and Wegovy in the UK — NHS vs Private Routes
NHS route: Both Mounjaro and Wegovy are available through NHS specialist weight management services (tier 3/4), but access is limited and varies significantly by region. You'll need a GP referral to your local integrated care board's weight management service. Waiting lists can be months to years in many areas. When available, NHS prescriptions are free after the standard prescription charge (currently £9.90 in England).
Private route: Online prescribing services offer faster access — typically within 24–48 hours. You'll complete an online health questionnaire, have a consultation with a UK-licensed prescriber, and if approved, your prescription is sent to a GPhC-registered pharmacy. This route costs £20–£50 for the consultation plus medication costs. No NHS waiting list, but you pay privately. Use our free GLP-1 weight loss calculator to explore projected outcomes at different doses before choosing a medication.
- 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 5mg stronger than Wegovy?
Mounjaro 5mg is broadly equivalent to Wegovy 0.5mg in terms of dosing schedules, but they work differently — Mounjaro uses dual GIP/GLP-1 action versus Wegovy's single GLP-1 mechanism. Clinical trials suggest Mounjaro may produce slightly greater average weight loss, but individual results vary. Your prescriber will recommend which suits you based on your health profile and previous medication responses.
Why does Wegovy cost less than Mounjaro in some places?
Costs vary by provider, stock availability, and promotional pricing rather than the medication itself being inherently cheaper. Wegovy may sometimes appear less expensive at certain private pharmacies, but Mounjaro pricing varies similarly. Always compare prices across multiple GPhC-registered services before deciding. Cost should be just one factor — clinical suitability matters more.
Can I switch from Mounjaro 5mg to Wegovy on the NHS?
Switching between GLP-1 medications on the NHS is possible but requires your GP or specialist to assess whether it's clinically appropriate. There's no automatic "switch" protocol — each change needs clinical justification. Private services may offer switches more flexibly, though any change should be managed by a prescriber for safety.
How long does private online prescribing take in the UK?
Most private online services deliver within 3–5 working days from consultation approval. You'll typically get results within 24–48 hours after completing your health assessment. NHS routes take significantly longer due to waiting lists — sometimes months. If rapid access is important to you, private prescribing is faster, though it costs more.
Do I need a GP letter to get Mounjaro or Wegovy privately?
No — private online prescribing services don't require a GP letter. You complete an online health questionnaire, and a UK-licensed prescriber reviews it independently. However, it's good practice to inform your GP that you're taking GLP-1 medication so they can monitor your health and adjust any other medications if needed.
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.