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 You Exercise on Mounjaro?
Yes, you can exercise while taking Mounjaro (tirzepatide), but there are some important considerations. Most people can maintain regular physical activity alongside this prescription weight management injection, though some may experience side effects that temporarily affect exercise capacity. Understanding how Mounjaro interacts with physical activity helps you stay safe and get the most from both the medication and exercise. This guide explains what to expect and how to exercise safely whilst taking tirzepatide.
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.
Exercise and Mounjaro: What You Need to Know
Exercise is actually encouraged whilst taking Mounjaro — clinical trials showed best results when medication was combined with a reduced-calorie diet and increased physical activity. However, some common side effects may temporarily affect your ability to exercise:
- Nausea and stomach upset — may be worse after eating; plan exercise for 2–3 hours after meals
- Fatigue and dizziness — start with light activity (walking, gentle cycling) before returning to intense exercise
- Dehydration risk — Mounjaro can cause diarrhoea; drink water consistently throughout the day and during exercise
- Low appetite — ensure adequate nutrition before and after workouts to maintain energy
Most side effects improve significantly by week 2–4 on each dose. During your dose titration (escalating doses every 4 weeks), it's normal to reduce exercise intensity temporarily. Your prescriber may adjust your Mounjaro dose schedule based on how you're managing side effects.
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.
Accessing Mounjaro in the UK: Cost and Routes
NHS access: Mounjaro is available through NHS tier 3 specialist weight management services, but availability varies significantly by region. GPs can refer you, though waiting lists can be several months in some areas. Once prescribed via the NHS, there's no direct cost per injection.
Private access: UK-licensed prescribers offer private online assessments — costs typically range from £129–£180 per month depending on your current dose. A clinical assessment must be completed before any prescription is issued. Private prescriptions are dispensed by GPhC-registered pharmacies. The Mounjaro KwikPen is the same medication whether accessed privately or via NHS.
Whether you choose NHS or private access, your prescriber will ensure Mounjaro is suitable for you before starting, and will monitor your progress and any side effects throughout your 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.
Will Mounjaro stop me from exercising?
No. Most people can exercise normally on Mounjaro. Some experience temporary side effects like nausea or fatigue, especially when starting or increasing doses, but these usually settle within a few weeks. Exercise is actually recommended as part of your treatment plan alongside the injection and dietary changes.
Should I exercise before or after taking my weekly Mounjaro injection?
There's no strict rule about timing. However, you may feel slightly more nauseous or fatigued for a few hours after your injection, so some people prefer to exercise on non-injection days or 24 hours after injection. Listen to your body and adjust based on how you feel.
What type of exercise is best whilst taking Mounjaro?
Any regular physical activity helps. Start with what feels manageable — walking, swimming, cycling, or gentle strength training are all effective. Aim for 150 minutes of moderate activity per week (NHS recommendation), but don't push too hard if you're experiencing side effects early on.
How much does Mounjaro cost in the UK privately?
Private Mounjaro costs vary by dose: starter doses (2.5–5mg) typically cost £129–£150/month, while higher maintenance doses (10–15mg) cost £160–£180/month. Prices vary between prescribers, so it's worth comparing. NHS access is free once prescribed, though regional availability varies.
How do I access Mounjaro — NHS or private — and what's the difference?
NHS: Referral from your GP to a specialist weight management service; free but potentially long waiting lists. Private: Online assessment with a UK-licensed prescriber; faster access but costs £129–£180/month. Both routes require a clinical assessment to confirm you're eligible. Your prescriber will discuss which route suits you best.
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.