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
Weight Loss Workout in Gym — Combined Approach in the UK
Gym workouts are a valuable part of any weight loss journey, but for many people in the UK, combining exercise with other evidence-based approaches — including prescription medication — can deliver better results. Whether you're starting at the gym or looking to optimise your weight management plan, understanding all available options is key. This guide covers how exercise fits alongside NHS-approved weight loss support, including prescription medications like Mounjaro and Wegovy that may be suitable for eligible adults.
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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.
UK-Licensed Prescription Weight Loss Options
If you're looking to lose weight in the UK, prescription weight loss medications are now available for eligible adults. The main options include Mounjaro (tirzepatide), a dual GIP and GLP-1 receptor agonist, and Wegovy (semaglutide), a GLP-1 agonist — both are once-weekly injections. Saxenda (liraglutide) is also available as a daily injection. These medications may help reduce appetite and support feeling fuller after meals, making them more effective when combined with gym workouts and reduced-calorie eating. In clinical trials, Mounjaro helped participants lose an average of 15–21% of body weight, whilst Wegovy showed average weight loss of around 15% — though individual results vary significantly. Eligibility typically requires a BMI of 30 or above, or 27 or above with weight-related health conditions like type 2 diabetes or high blood pressure. All prescription weight loss medications are only available with a prescription and clinical assessment.
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 and Getting Started
In the UK, you can access prescription weight loss medication through the NHS or privately. NHS access is via specialist tier 3 weight management services — usually requiring a GP referral — though availability and waiting times vary significantly by region. Private access is available through online consultations with UK-licensed prescribers, without needing an NHS referral. Your GP can assess your eligibility and discuss whether medication alongside your gym routine is appropriate for you. To check if you might qualify, use our free BMI calculator above to determine your current BMI category. Even if you're not eligible for medication now, gym workouts combined with sustainable dietary changes remain highly effective. Our GLP-1 weight loss calculator can help you estimate potential results if medication becomes an option in future.
- 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 use prescription weight loss medication if I go to the gym regularly?
Yes. Prescription weight loss medications like Mounjaro and Wegovy are designed to be used alongside exercise and a reduced-calorie diet — not instead of them. Combining medication with gym workouts typically produces better results than either approach alone. Your prescriber will discuss how to integrate both strategies safely.
What's the difference between Mounjaro and Wegovy for weight loss?
Both are once-weekly injections licensed for UK weight management. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, whilst Wegovy (semaglutide) is a GLP-1 agonist only. In trials, Mounjaro showed slightly higher average weight loss (up to 21%) compared to Wegovy (around 15%), though individual results vary. Your prescriber can discuss which may suit you better.
How much weight can I expect to lose combining gym workouts and medication?
Weight loss varies greatly between individuals and depends on diet, exercise consistency, medication dose, and personal factors. Clinical trials show prescription medications help achieve 15–clinically studied weight loss on average when combined with lifestyle changes. A modest calorie deficit (around 500 kcal/day) from diet and gym workouts typically results in approximately 0.5 kg per week loss.
Can I get prescription weight loss medication through the NHS?
Yes, but access varies by region. NHS weight loss medication is available through specialist tier 3 weight management services, usually requiring a GP referral. Waiting times can be lengthy in some areas. Private access via online prescribing is also available in the UK without an NHS referral.
Is my BMI high enough for prescription weight loss medication?
Use our free BMI calculator on this page to check your BMI category. Typical eligibility is BMI 30 or above, or BMI 27–29.9 with weight-related health conditions. However, eligibility also depends on your overall health, medical history, and individual circumstances — your GP or a licensed prescriber will make the final assessment.
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.