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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Wegovy vs Mounjaro Dosing — UK Cost and Access
Both Wegovy and Mounjaro are prescription-only weight management injections available in the UK, but they differ significantly in dosing schedules, costs, and how you access them. Wegovy uses a gradual dose escalation starting at 0.25mg, while Mounjaro begins at a higher 2.5mg dose. This guide explains the dosing differences, what each costs privately, and your options for accessing either medication through the NHS or private prescription routes.
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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.
Wegovy and Mounjaro Dosing Schedules Compared
Wegovy dosing follows a longer titration schedule over 16 weeks, starting at 0.25mg and gradually increasing to the maximum 2.4mg maintenance dose. Each dose is held for 4 weeks before escalation, making the journey to full dose slower and potentially allowing more gradual adjustment to side effects.
Mounjaro dose titration is faster, beginning at 2.5mg and reaching maximum 15mg typically within 20 weeks. Mounjaro offers five escalation steps compared to Wegovy's four, providing more incremental adjustments.
- Wegovy: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg (16+ weeks)
- Mounjaro: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg (20+ weeks)
Both are once-weekly injections. The slower Wegovy titration may suit some patients; the more gradual Mounjaro adjustments may benefit others. Clinical trials show similar average weight loss outcomes — approximately 15-21% of body weight — though tirzepatide (Mounjaro's active ingredient) demonstrated slightly higher average loss in SURMOUNT data at maximum doses.
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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.
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UK Private Prescription Costs and NHS Access
Private prescription costs in the UK vary by dose and provider. Wegovy typically ranges from £129–£199 monthly for lower doses (0.5–1mg) to £249–£299 for the maximum 2.4mg dose. Mounjaro generally costs £180–£249 for 5–7.5mg and £269–£349 for higher doses, reflecting the greater tirzepatide content. Initial appointments with online prescribers cost £50–£150, with ongoing follow-ups often included.
NHS access through tier 3 specialist weight management services is available but varies significantly by region and has substantial waiting lists — often 6–18 months in many areas. NICE has approved both medications for NHS use in eligible patients (BMI ≥30, or ≥27 with weight-related health conditions). Your GP can refer you, but NHS prescription availability depends on your local Integrated Care Board commissioning decisions.
The online prescription process is straightforward: complete a consultation form with health history, speak briefly with a UK-licensed prescriber (video or telephone), and receive a prescription if deemed suitable. Dispensing typically takes 2–5 working days. You must provide an address for delivery and confirm you are not pregnant or planning pregnancy within 4 weeks of starting or dose increases.
- 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 Wegovy cheaper than Mounjaro in the UK?
Costs are similar at equivalent doses. Wegovy ranges £129–£299/month, Mounjaro £180–£349/month depending on dose. Lower-dose Wegovy may be slightly cheaper initially, but at maximum doses costs are comparable. Always compare your specific dose with multiple providers.
Can I get Wegovy or Mounjaro on the NHS?
Yes, both are approved by NICE for NHS specialist weight management services. Access requires referral from your GP to a tier 3 service, but availability varies by region. Waiting lists can be several months to over a year depending on your local area.
How long does it take to reach the full Wegovy dose?
Wegovy reaches maximum 2.4mg dose in 16 weeks with four escalation steps (0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg). Each dose is maintained for 4 weeks before increasing. Some patients stay at lower doses if they achieve their weight loss goals.
What's the difference between Mounjaro's KwikPen and Wegovy's auto-injector?
Mounjaro uses a pre-filled KwikPen with a dial mechanism; Wegovy uses a pre-filled auto-injection pen. Both deliver a subcutaneous injection once weekly. The KwikPen allows you to select your dose; Wegovy pens contain a fixed dose per injection.
Does private prescription cost include follow-up appointments?
This varies by provider. Some include ongoing GP-style follow-ups (video or telephone) every 4–12 weeks; others charge per consultation. Ask your prescriber about follow-up costs before purchasing, and use our GLP-1 weight loss calculator to monitor expected progress between appointments.
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.