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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Restarting Mounjaro After Surgery in the UK
If you've had surgery and need to restart Mounjaro (tirzepatide), understanding how to access it again and what it will cost is important for your weight management journey. Whether you paused your treatment before a procedure or are now ready to resume, this guide covers your UK options for restarting prescription Mounjaro, including both NHS specialist services and private online prescribing routes, plus realistic cost expectations.
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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.
Private Prescription Cost and Access in the UK
In the UK, Mounjaro is a prescription-only medicine that costs between approximately £150–£320 per month depending on your dose through private prescribing. The 2.5 mg starting dose typically costs around £150–£180, while the maximum 15 mg dose ranges from £250–£320. Private online pharmacies that are GPhC-registered offer consultations with UK-licensed prescribers who assess whether restarting post-surgery is clinically appropriate for you.
- Starting dose (2.5 mg) — typically £150–£180 per month
- Mid-range doses (7.5–10 mg) — approximately £200–£240 per month
- Maximum dose (15 mg) — £250–£320 per month
- Each KwikPen contains 4 weekly injections
- Private prescriptions do not require NHS referral
- Online consultation fee usually included in medicine cost or charged separately (typically £50–£100)
Post-surgery, you may restart on your previous dose or begin at the starting dose of 2.5 mg — this depends on individual clinical assessment.
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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.
Free Weight Loss Tools & Guides
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NHS vs Private: Accessing Mounjaro After Your Recovery
NHS access: Available through tier 3 specialist weight management services, but typically requires referral from your GP and can involve lengthy waiting lists (months to over a year in many regions). Your GP can refer you post-surgery if you were previously on Mounjaro through the NHS.
Private access: Faster alternative — you can book an online consultation with a UK-licensed prescriber within days. The prescriber reviews your medical history, post-surgery recovery status, and current health before deciding whether restarting is suitable. If approved, your Mounjaro prescription is sent to a GPhC-registered pharmacy for delivery to your home. Use our GLP-1 weight loss calculator to explore projected outcomes at different doses as you plan your restart.
- 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 restart Mounjaro immediately after surgery?
No — your prescriber will assess your recovery status first. Most guidelines suggest waiting until you're fully healed and cleared by your surgical team (typically 4–8 weeks). Your prescriber may restart you at a lower dose and titrate upwards, or resume your previous dose depending on individual circumstances.
Will restarting Mounjaro after surgery cost more than before?
Private prescription costs remain consistent — typically £150–£320 per month depending on dose. If you were previously on NHS Mounjaro, private access costs more. However, some private providers offer package pricing or discounts for long-term customers. Always ask about current pricing before committing.
What should I tell my prescriber about my surgery?
Inform your prescriber of: the type of surgery you had, the date, any ongoing recovery issues, current medications, and any dietary restrictions. This helps them assess whether tirzepatide is safe to restart and whether your dose should be adjusted. Honesty about your recovery is important for your safety.
How long does it take to restart Mounjaro through private prescription?
Typically 3–7 days from online consultation to delivery. You book an appointment (often available within 24–48 hours), have a brief online consultation with a prescriber, and if approved, your prescription is processed and sent to a GPhC-registered pharmacy for dispatch to your home address.
Is restarting at a lower dose after surgery more cost-effective?
Yes — the 2.5 mg starting dose costs approximately £150–£180 per month, roughly £100 less than the maximum 15 mg dose. However, lower doses may deliver less weight loss support. Your prescriber will balance cost, safety, and your weight management goals when recommending a restart dose.
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.