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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Weight Loss Workouts For Gym In The UK
Gym workouts are an effective part of any weight loss programme, but many people find combining exercise with prescription weight loss medication produces better results. In the UK, adults eligible for weight management support can access prescription options including Mounjaro and Wegovy through NHS specialist services or private prescribing. This guide explains how gym workouts fit into a comprehensive weight management approach, what medication options are available, and how to find out if you're eligible for prescription weight loss support alongside your fitness routine.
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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.
UK Prescription Weight Loss Options Available Now
Three prescription weight loss medications are currently licensed in the UK for weight management: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). Mounjaro and Wegovy are once-weekly injections, while Saxenda is a daily injection.
In clinical trials, adults using these medications lost an average of 14–21% of their body weight when combined with reduced-calorie diet and exercise. Individual results vary significantly, and these are prescription-only medicines requiring clinical assessment before use. They work by activating natural hormone pathways that help reduce appetite, support feeling fuller after meals, and may improve metabolic health.
Eligibility typically includes adults with a BMI of 30 or above, or 27 or above if you have weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply due to higher health risks at lower weights.
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 Access Versus Private Prescribing In The UK
NHS access: Prescription weight loss medications are available through specialist tier 3 and tier 4 weight management services. You'll need a referral from your GP, and availability varies significantly by region. Waiting lists can be lengthy in many areas, sometimes stretching many months.
Private access: GPhC-registered online pharmacies offer prescription weight loss treatment following an online clinical assessment with a UK-licensed prescriber. This route doesn't require NHS referral and may be faster, though costs apply—typically £129–£320 monthly depending on dose. Either route, combined with gym workouts and a balanced diet, can support meaningful weight loss. Speak to your GP about which option suits your circumstances.
- 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 combine gym workouts with Mounjaro or Wegovy?
Yes. Clinical trials showed that prescription weight loss medication works best alongside reduced-calorie diet and increased physical activity. Gym workouts remain important whether you use medication or not. Your prescriber can advise on activity levels as you start treatment, since some people experience fatigue during initial adjustment phases.
How much weight can I expect to lose combining exercise and weight loss medication?
In trials, people using Mounjaro lost an average of 15–21% of body weight; Wegovy users lost around 15% on average. These are alongside diet and exercise. Individual results vary significantly. You can use our free GLP-1 weight loss calculator above to estimate potential outcomes at different doses, though personal results depend on many factors.
What is the fastest safe rate of weight loss with gym workouts and medication?
The NHS recommends losing no more than 0.5–1 kg per week for sustainable results. Faster loss risks muscle loss and nutritional deficiency. Prescription medications can accelerate loss beyond diet and exercise alone, but safe rate still applies. Your prescriber will monitor progress and adjust treatment accordingly.
Do I need to be overweight to access prescription weight loss medication in the UK?
Eligibility requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions like diabetes or high blood pressure. Use our free BMI calculator above to check your personal BMI. If you're below these thresholds, your GP can advise on other weight management options available to you.
How do I start the conversation with my GP about prescription weight loss options?
Ask your GP about NHS weight management services in your area or mention that you're interested in exploring prescription options for weight loss. They can assess your eligibility, discuss whether medication suits you, and either refer you to specialist services or discuss private options. Be honest about your fitness routine and health goals.
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.