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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Mounjaro and Exercise — Side Effects, Cost & Access Guide
If you're considering Mounjaro (tirzepatide) for weight management and wondering how exercise fits in, you're right to ask. Exercise is a cornerstone of sustainable weight loss alongside prescription medication, but Mounjaro can cause side effects that may affect your physical activity. This guide explains how to exercise safely on Mounjaro, what side effects you might experience, and the cost and access options available to UK adults. Whether you're exploring NHS routes or private prescription, we'll help you understand the full picture.
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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.
Exercise Side Effects and How to Manage Them on Mounjaro
Mounjaro works as a dual GIP and GLP-1 receptor agonist, helping regulate appetite and support feeling fuller after meals. However, common side effects like nausea, diarrhoea, constipation, and fatigue can make exercise feel challenging, especially in the first few weeks of treatment or when doses increase. These effects typically improve within 1–2 weeks as your body adjusts, though timing varies between individuals.
To exercise safely on Mounjaro, start with gentle activity like walking or light stretching if you're experiencing nausea or stomach discomfort. Avoid intense exercise immediately after taking your weekly injection, and stay well-hydrated—Mounjaro can increase dehydration risk. Listen to your body: if you feel dizzy, severely fatigued, or experience sharp abdominal pain, stop exercising and contact your GP. As side effects ease, you can gradually return to more vigorous activity.
Many people find that light to moderate exercise (30 minutes of walking most days) feels manageable even during the adjustment phase, and helps with overall weight loss outcomes. Use our free GLP-1 weight loss calculator above to estimate your projected results when combining Mounjaro with regular physical activity.
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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.
Mounjaro Cost and Access in the UK — NHS vs Private Routes
NHS access to Mounjaro: NICE has approved tirzepatide for specialist weight management services, but availability varies significantly by region. You'll need a GP referral to tier 3 or tier 4 specialist services, and waiting lists can be several months to over a year depending on your area. Once prescribed, Mounjaro is free on the NHS.
Private access and cost: Private prescription through a UK-licensed prescriber costs approximately £130–£280 per month depending on your dose. You'll complete an online consultation with a prescriber, receive a prescription if clinically appropriate, and have Mounjaro dispensed by a GPhC-registered pharmacy. The full dose titration schedule (from 2.5 mg to your maintenance dose) typically takes 20 weeks, so budget for 5 months of treatment cost upfront.
Calculate your potential weight loss outcomes and compare your options using our free weight loss calculator on this page.
What to expect in a private online consultation: A UK-licensed prescriber will assess your medical history, current medications, BMI, and weight-related health conditions to determine if Mounjaro is suitable. The consultation takes 10–15 minutes and covers eligibility criteria, realistic outcomes (individual results vary), possible side effects, and storage requirements for your KwikPen device. If approved, your prescription is sent electronically to a pharmacy, and Mounjaro arrives within 2–5 working days. Subsequent doses are typically ordered as you progress through the titration schedule.
Check your BMI using our free BMI calculator above to understand where you sit on NHS weight management thresholds. Adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions (like type 2 diabetes or high blood pressure), may be eligible for prescription weight loss treatment.
- 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 exercise intensely while taking Mounjaro?
Light to moderate exercise like walking or swimming is generally safe on Mounjaro, especially once side effects settle. Intense exercise may be difficult during nausea or fatigue phases. Always consult your GP before starting a new exercise programme, and avoid exercise immediately after your injection. Stop immediately if you feel dizzy or experience severe abdominal pain.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs approximately £130–£280 per month depending on your dose level. The full titration from 2.5 mg to maximum dose takes about 5 months, so expect initial costs around £650–£1,400 for the complete dose progression. Prices vary by pharmacy and prescriber.
Can I get Mounjaro on the NHS?
Yes, NICE has approved tirzepatide for NHS specialist weight management services. You'll need a GP referral to tier 3 or tier 4 services. Availability and waiting times vary significantly by region—some areas have long waiting lists. Once prescribed, Mounjaro is free on the NHS.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, while Wegovy (semaglutide) is a GLP-1 agonist only. Mounjaro has shown slightly higher average weight loss in clinical trials (~20.9% vs ~14.9%), though individual results vary significantly. Both are once-weekly injections available through NHS specialist services or private prescription.
How do I know if I'm eligible for Mounjaro?
Adults with a BMI of 30 kg/m² or above, or BMI of 27–29.9 with at least one weight-related health condition (such as type 2 diabetes, high blood pressure, or sleep apnoea), may be eligible. South Asian, Chinese, Black African, and Black Caribbean adults may qualify at lower BMI thresholds. Use our BMI calculator above to check your BMI, then consult your GP or a licensed prescriber about 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.