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 Is 1mg Wegovy Equivalent to Mounjaro?
1mg Wegovy is approximately equivalent to 5-7.5mg Mounjaro, though there is no official NHS or MHRA conversion chart. Both Wegovy (semaglutide) and Mounjaro (tirzepatide) are prescription-only weight management injections licensed in the UK, but they use different mechanisms and dose ranges. If you're considering switching between them or want to understand how dosages compare, it's important to speak with your prescriber, as individual tolerability and response vary significantly.
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.
Approximate Wegovy to Mounjaro Dose Equivalence
While no formal conversion exists between Wegovy and Mounjaro, clinical practice and trial data suggest approximate equivalences:
- 0.5–1mg Wegovy ≈ 5mg Mounjaro (both lower maintenance doses)
- 1.7mg Wegovy ≈ 7.5–10mg Mounjaro (mid-range escalation)
- 2.4mg Wegovy ≈ 10–15mg Mounjaro (maximum licensed doses)
These are approximate equivalences based on clinical outcomes in trials, not official conversions. Mounjaro's dual GIP+GLP-1 mechanism may produce different weight loss and side effect profiles compared to Wegovy's single GLP-1 pathway, even at equivalent doses. Your prescriber will assess which medication and dose is most appropriate for your individual health needs.
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.
UK Cost and Private Access Pathway
Private prescription costs for Wegovy in the UK typically range from £150 to £300 per month, depending on dose strength and provider. Access via private online consultation with a UK-licensed prescriber is quicker than NHS routes, often with initial assessment within days.
NHS access to Wegovy is through tier 3 specialist weight management services, usually requiring GP referral. Waiting times vary significantly by region; many areas have delays of several months. Use our free BMI calculator and GLP-1 weight loss calculator to understand your eligibility and potential outcomes before consulting your prescriber.
- 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.
Can I switch directly from 1mg Wegovy to an equivalent Mounjaro dose?
No. Any switch between medications must be managed by your prescriber. You cannot simply switch doses — your prescriber will assess your health, side effects, and response before recommending a new starting dose, which may be lower than the equivalent dose to allow your body to adjust.
Is Mounjaro more effective than 1mg Wegovy?
Clinical trials suggest Mounjaro may produce slightly greater average weight loss than Wegovy across all doses, but individual results vary significantly. At 1mg Wegovy (a relatively low dose), Mounjaro at an equivalent dose might produce different results depending on your personal response. Your prescriber can discuss what to expect.
What does "equivalent dose" actually mean?
It means the doses produce approximately similar weight loss and side effects in clinical trials on average. However, this is not an official conversion — it's based on clinical practice experience. Your individual response to either medication depends on metabolism, adherence, lifestyle, and other health factors.
How long does it take to switch from Wegovy to Mounjaro in the UK?
This depends on your prescriber. You'll typically have a consultation to discuss the switch, then a new prescription issued. Some private providers can switch within days; NHS routes may take weeks. During any switch, there may be a gap while your body transitions between medications.
Which is cheaper in the UK — Wegovy or Mounjaro?
Private costs are similar (£150–£300/month depending on dose), though prices vary by provider. NHS access for both has long waiting lists and regional variation. Neither is available over-the-counter. Private online prescribing is faster but more expensive than NHS. ```
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.