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 Your GP Prescribe Wegovy in the UK?
Your GP can prescribe Wegovy (semaglutide) in the UK, but access depends on whether you use the NHS or private route. On the NHS, GPs refer eligible patients to specialist tier 3 weight management services where Wegovy may be prescribed as part of a comprehensive weight management programme. Private access is available through online consultations with UK-licensed prescribers, with dispensing through GPhC-registered pharmacies. This guide explains your options, costs, and what to expect from each route.
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.
Wegovy Prescription Cost in the UK
Private prescription costs for Wegovy typically range from £130 to £300 per month, depending on the dose and pharmacy. Most providers charge per dose or per month of treatment. The 2.4 mg maintenance dose (maximum strength) usually costs between £200 and £300 monthly for ongoing treatment. Initial starter packs containing lower doses (0.25 mg, 0.5 mg, 1 mg) may cost slightly less. Costs often include the online consultation fee with a UK-licensed prescriber. Some providers offer discounts for upfront payment of multiple months. On the NHS, if you are prescribed Wegovy through a specialist weight management service, the medication is dispensed free as part of your NHS treatment, though waiting times for specialist referral can be significant in many areas. Individual prices vary, so it is worth comparing registered providers. Always verify that any provider you choose operates through a GPhC-registered pharmacy.
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.
NHS vs Private Access Routes
NHS route: Your GP refers you to your local tier 3 specialist weight management service if you meet eligibility criteria (BMI 30 or above, or 27+ with weight-related health conditions). The service conducts a comprehensive assessment and prescribes Wegovy if appropriate. Medication is free, but waiting lists vary from months to over a year in some regions. This is the evidence-based, supported pathway but availability depends on your location.
Private route: You complete an online consultation with a UK-licensed prescriber without needing an NHS referral. If approved, your prescription is dispensed by a GPhC-registered pharmacy. This is faster (typically days) and does not require referral, but you pay privately. Both routes offer medical oversight—the difference is speed, cost, and who manages your care. Your GLP-1 weight loss calculator can help estimate potential outcomes regardless of which route you choose.
- 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.
Will my GP prescribe Wegovy without a specialist referral?
Your GP can issue a private prescription for Wegovy if they are willing to do so, though many will refer you to specialist services instead. For NHS prescription, you must be referred to a specialist tier 3 weight management service. Many GPs prefer specialist oversight because weight management injections require ongoing monitoring and dose adjustments. Ask your GP about both NHS referral and private prescription options.
How long does it take to get Wegovy on the NHS?
NHS waiting times vary significantly by region. Some areas have waiting lists of 3–6 months, whilst others may wait 12 months or longer. This depends on your local ICB's funding and specialist service capacity. Private access is faster, typically 3–7 days from consultation to first dose. If speed is important, discuss both options with your GP.
Can I switch from Mounjaro to Wegovy on the NHS?
Yes, switching between GLP-1 medications is possible but requires prescriber guidance. If you are on Mounjaro through an NHS specialist service and your prescriber recommends switching to Wegovy (semaglutide), they will manage this transition. Private prescribers can also facilitate switches. Any change must be managed by your healthcare provider—do not self-switch between medications.
What happens during a private Wegovy consultation?
You complete a health questionnaire online covering your medical history, current medications, weight, height, and lifestyle. A UK-licensed prescriber reviews this and may ask follow-up questions via video or phone call. If approved, they issue a prescription. You then receive Wegovy directly from a GPhC-registered pharmacy. The whole process typically takes 1–7 days. You remain responsible for reporting side effects to the prescriber.
Is Wegovy cheaper on the NHS or private?
Wegovy is free on the NHS but involves referral and waiting time. Privately, you pay £130–£300 monthly but avoid waiting lists and NHS referral requirements. The NHS is cheaper if you can access it, but private access offers immediate treatment. Consider your priorities: cost versus speed and regional NHS availability. Use our BMI calculator to confirm your eligibility for either route.
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.