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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Going Back On Mounjaro After A Break — What You Need To Know
If you've paused your Mounjaro treatment and want to restart, you'll need to go through a new clinical assessment with a prescriber. Depending on how long your break was and your current health, you may need to restart at a lower dose or continue from where you left off. In the UK, you can access Mounjaro (tirzepatide) through either NHS specialist weight management services or private online prescription routes, each with different costs and timelines. This guide covers what happens when you restart, how much it costs, and the quickest way to get back on treatment.
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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 Mounjaro Access And Costs In The UK
In the UK, private Mounjaro prescriptions cost between £130 and £300 per month, depending on your current dose and the online prescribing service you use. Most costs break down as:
- 2.5–5 mg dose: approximately £129–£149 per month
- 7.5–10 mg dose: approximately £149–£199 per month
- 12.5–15 mg dose: approximately £199–£320 per month
When restarting after a break, you'll typically need a new online consultation (usually £20–£50). If your break was several months or longer, your prescriber will reassess your eligibility and may recommend dose titration—restarting at 2.5 mg even if you were previously on a higher dose, to allow your body to readjust. The KwikPen itself (containing 4 weekly injections) is usually included in the prescription cost. Private access is fastest, typically dispensing within 3–5 working days of prescription approval, making it ideal if you want to restart quickly without NHS waiting lists.
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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
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
NHS Vs Private: Which Route Works For Restarting?
NHS access requires referral to a specialist tier 3 or tier 4 weight management service, usually through your GP. If you've been off treatment for a while, you may need to be re-referred. NHS waiting lists vary dramatically by region—some areas have waits of 6–18 months. Once approved, Mounjaro is free on the NHS, but you'll also follow NHS dose titration protocols and attend specialist clinic appointments.
Private access is faster and doesn't require an NHS referral. You complete an online health questionnaire, speak with a UK-licensed prescriber via video consultation or phone, and if approved, receive your prescription within days. This route suits people who want to restart immediately and are willing to cover costs privately. Both routes require a clinical assessment before prescribing—prescribers need to confirm you're still eligible and that restarting is medically appropriate.
- 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.
Do I need to restart Mounjaro at the lowest dose after a break?
It depends on how long your break was and your prescriber's assessment. If your break was a few weeks, you might continue from your previous dose. If it was several months or longer, restarting at 2.5 mg is often recommended to allow your body to readjust and minimise side effects. Your prescriber will decide based on your individual circumstances.
How much does a private Mounjaro prescription cost in the UK?
Private Mounjaro costs between £130 and £320 per month depending on dose. Lower doses (2.5–5 mg) cost around £130–£150, mid-range doses (7.5–10 mg) cost £150–£200, and higher doses (12.5–15 mg) cost £200–£320. This typically includes the KwikPen and online consultation fees.
Can I get Mounjaro free on the NHS if I'm restarting after a break?
Yes, if you're eligible and referred to an NHS specialist weight management service. However, NHS waiting times vary significantly by region—some areas have 6–18 month waits. You'll need GP referral and will follow NHS dose titration protocols. Private prescription is faster if you want to restart within days.
What should I tell my prescriber when restarting Mounjaro?
Tell your prescriber how long your break was, why you stopped (side effects, cost, personal reasons), your current weight and health status, any new medications, and whether you experienced any changes in appetite or weight during your time off. This helps them decide on dose and assess whether restarting is appropriate for you.
Is the Mounjaro KwikPen cost included in private prescription prices?
Yes, private prescription costs typically include the KwikPen (pre-filled injection device with 4 doses). Storage is your responsibility—unopened pens should be kept in a fridge at 2–8°C, and used pens can be stored at room temperature for up to 30 days after first use.
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.