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
Can I Get Mounjaro Online in the UK?
Yes, you can get Mounjaro online in the UK through private prescribing services and GPhC-registered pharmacies, but only with a valid prescription from a UK-licensed healthcare professional. Mounjaro (tirzepatide) is a prescription-only weight management injection that requires a clinical assessment before supply. You can also access it through NHS specialist weight management services, though availability varies by region and waiting times can be lengthy. This guide explains your options and how Mounjaro compares to Wegovy online.
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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.
How to Access Mounjaro Online vs Wegovy in the UK
Both Mounjaro (tirzepatide) and Wegovy (semaglutide) are available online in the UK through private prescribing, but they work differently:
- Mounjaro is a dual GIP and GLP-1 receptor agonist — activating two hormone pathways to regulate appetite and blood sugar
- Wegovy is a GLP-1 agonist only — working through a single hormone mechanism
- Clinical trial data (SURMOUNT for Mounjaro, STEP for Wegovy) showed Mounjaro users lost an average of 15–21% body weight, while Wegovy users lost approximately 15% on average
- Both require a KwikPen injection once weekly
- Both start at low doses and require titration — Mounjaro doses from 2.5 mg to 15 mg, Wegovy doses from 0.25 mg to 2.4 mg
Eligibility for both medications requires a BMI of 30 or above, or 27 or above with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea.
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.
Which Medication Suits You — Individual Assessment Matters
Choosing between Mounjaro and Wegovy online depends on your individual health profile, and a prescriber must assess suitability before issuing a prescription. A licensed UK prescriber will consider your medical history, current medications, and weight loss goals. Some people respond better to dual-action GIP+GLP-1 therapy (Mounjaro), whilst others achieve good results with GLP-1 alone (Wegovy). Both require a healthy lifestyle — diet and physical activity — alongside medication for best results. Use our free GLP-1 weight loss calculator to estimate potential outcomes at different doses, and our BMI calculator to understand where you stand now.
- 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 get Mounjaro online without seeing my GP first?
You do not need a GP referral for online private prescribing, but you must complete a clinical assessment with a UK-licensed prescriber via an online consultation. They will review your health, medications, and eligibility before issuing a prescription. This is a legal and safety requirement for all prescription-only medicines.
Is Mounjaro cheaper than Wegovy online in the UK?
Pricing varies by provider and dose. Generally, both medications cost between £129–£320 per month privately, depending on the dose you need. Lower starting doses (Mounjaro 2.5 mg or Wegovy 0.25 mg) are usually less expensive than higher maintenance doses. Compare providers for current pricing.
How long does it take to receive Mounjaro after ordering online?
Delivery times vary by pharmacy, but most GPhC-registered online pharmacies deliver within 2–5 working days after your prescription is approved. Some offer next-day delivery options. Always check the pharmacy's delivery policy before ordering.
What's the difference between Mounjaro dose titration and Wegovy dose titration?
Mounjaro titration starts at 2.5 mg and increases every 4 weeks (5 mg, 7.5 mg, 10 mg, 12.5 mg, 15 mg max). Wegovy starts at 0.25 mg and increases weekly (0.5 mg, 1 mg, 1.7 mg, 2.4 mg max). Both require minimum time at each dose before increasing, and your prescriber will guide your personal titration schedule.
Can I switch from Mounjaro to Wegovy online, or vice versa?
Switching between medications requires a new clinical assessment and prescription from your prescriber. There is no official conversion chart — approximate equivalences exist (Mounjaro 10 mg ≈ Wegovy 1.7 mg), but any switch must be managed by a licensed healthcare professional. Do not stop one medication and start another without guidance.
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.