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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Can I Get Mounjaro on NHS Wales?
Yes, Mounjaro (tirzepatide) is available through NHS Wales, but access is limited to specialist weight management services and involves specific eligibility criteria. You cannot get Mounjaro directly from your GP — you need a referral to a tier 3 or tier 4 specialist weight management service. Availability varies significantly across NHS Wales health boards, and waiting lists can be several months long. If you don't want to wait for NHS access, private prescription routes are available through UK-licensed online prescribers, though these involve a cost. This guide explains both pathways and what to expect.
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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.
NHS Wales Access to Mounjaro: Eligibility and Waiting Times
NHS Wales eligibility for Mounjaro:
- BMI of 30 kg/m² or above, or BMI of 27–29.9 with a weight-related health condition (type 2 diabetes, prediabetes, high blood pressure, sleep apnoea, cardiovascular disease, or abnormal blood fats)
- For people of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply — eligibility may begin at BMI 27.5 or above
- Must be referred by your GP to a specialist tier 3 weight management service
- Must have tried lifestyle interventions (diet and exercise) first
Access through NHS Wales is decided by individual health boards. NICE approved tirzepatide (Mounjaro's active ingredient) for NHS use, but regional variation in funding and availability is significant. Some health boards fund Mounjaro readily; others have restricted budgets or longer waiting lists. Waiting times typically range from 3 to 12 months depending on your area. During this time, you may be offered other NHS support such as dietitian consultations or lower-cost GLP-1 alternatives like Saxenda (liraglutide), which is a once-daily injection rather than Mounjaro's once-weekly KwikPen dose.
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.
Private Prescription Routes and NHS vs Private Comparison
If NHS Wales waiting times don't suit you, private prescription is available through UK-licensed online prescribers following an online clinical assessment. A prescriber will review your health details and issue a prescription if appropriate, which is then dispensed by a GPhC-registered pharmacy. Private Mounjaro costs typically range from £129 to £320 per month depending on dose — lower doses (2.5–5 mg) cost less than higher maintenance doses (10–15 mg). This is faster than NHS access but involves upfront cost. Use our free GLP-1 weight loss calculator to estimate potential results at different doses, and our BMI calculator to check your current eligibility. Many people choose the NHS route if they can wait; others prefer private access for speed and convenience.
- 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.
What's the difference between NHS and private Mounjaro in the UK?
NHS Mounjaro is free but requires GP referral to a specialist service and involves waiting lists (typically 3–12 months). Private Mounjaro requires an online clinical assessment and prescription but costs £129–£320/month and is available within days. Both use the same medication and dose ranges.
Do all NHS Wales health boards fund Mounjaro?
NICE approved tirzepatide for NHS use, but availability and funding vary by health board. Some regions have better access and shorter waiting lists than others. Ask your GP about your specific health board's policy.
What happens during a private Mounjaro consultation?
You'll complete an online health questionnaire, a UK-licensed prescriber reviews your details, and if approved, you'll receive a prescription. This usually takes 24–48 hours. You won't meet the prescriber face-to-face.
Can I switch from NHS to private Mounjaro or vice versa?
Yes. If you start private and want to switch to NHS, ask your GP for a referral to a specialist service. If you're on an NHS waiting list and start private treatment, inform your GP to avoid duplication.
What if I don't meet NHS Mounjaro eligibility criteria?
If your BMI is 25–29.9 without weight-related health conditions, you typically don't qualify for prescription weight loss treatment on the NHS. Private routes require clinical assessment but have no specific BMI threshold — a prescriber assesses individual suitability.
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.