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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Gym Programs For Weight Loss In The UK
Gym programs are an effective part of weight management, but they work best alongside a reduced-calorie diet. In the UK, there are several approaches to supporting weight loss: structured fitness plans, lifestyle changes, and for eligible adults, prescription weight management medication. This guide covers gym-based strategies alongside NHS weight loss options and prescription medications like Mounjaro and Wegovy. Whether you're starting your fitness journey or exploring all available support, understanding what works best for your circumstances is essential.
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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.
Gym Programs And Prescription Weight Management In The UK
Gym programs alone typically produce modest weight loss without dietary changes. The NHS recommends combining regular physical activity with a reduced-calorie diet for sustainable results. For adults struggling with weight management, the UK offers several additional support options.
UK-licensed prescription weight loss medications include:
- Mounjaro (tirzepatide) — a once-weekly injection that may help reduce appetite and support weight management alongside gym work and diet changes
- Wegovy (semaglutide) — a once-weekly GLP-1 injection that clinical trials showed helps with average weight loss of around 15% body weight
- Saxenda (liraglutide) — a once-daily injection option for eligible adults
Prescription weight loss medication is available through NHS specialist weight management services or private prescribing following a clinical assessment. Eligibility typically requires a BMI of 30 or above, or 27 or above with weight-related health conditions. These medications are designed to work alongside lifestyle changes, not replace them — meaning your gym program and dietary improvements remain central to success.
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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.
Finding NHS Support And Checking Your Eligibility
If you're interested in prescription weight management options, your first step is a conversation with your GP. They can assess your personal health circumstances and refer you to your local NHS specialist tier 3 weight management service if appropriate. NHS availability varies significantly by region, and waiting lists can be lengthy in some areas.
Alternatively, you can access prescription weight loss medication through private online prescribing services, which involve a clinical assessment with a UK-licensed prescriber. To understand whether you might be eligible, calculate your BMI using our free BMI calculator above — this gives you a starting point for discussion with your GP or a prescriber. Combined with regular gym attendance and sustained dietary changes, prescription support can help maximise your weight loss efforts.
- 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 lose weight from gym programs alone without changing my diet?
Gym programs can support weight loss, but calorie deficit is essential — typically requiring a 500 kcal daily reduction for around 0.5 kg weekly loss. Exercise alone rarely produces significant weight loss without dietary changes. The NHS recommends combining regular physical activity with reduced-calorie eating for best results.
What gym activities are most effective for weight loss?
A combination of cardiovascular exercise (running, cycling, swimming) and resistance training is most effective. Aim for 150 minutes of moderate cardio weekly plus 2 days of strength work. The specific activity matters less than consistency and maintaining a calorie deficit — choose activities you'll stick with long-term.
Am I eligible for prescription weight loss medication in the UK?
You may be eligible if your BMI is 30 or above, or 27 or above with weight-related health conditions like type 2 diabetes, high blood pressure, or cardiovascular disease. Use our free BMI calculator to check your starting point, then discuss with your GP or a licensed prescriber to assess suitability.
Can I use prescription weight loss medication alongside my gym program?
Yes — medications like Mounjaro and Wegovy are designed to work alongside lifestyle changes, including exercise and diet. Prescription support combined with regular gym attendance and calorie deficit typically produces better results than any single approach alone.
How do I access prescription weight loss medication on the NHS?
Ask your GP for a referral to your local NHS tier 3 specialist weight management service. They assess eligibility and can prescribe medications like Mounjaro or Wegovy. Availability varies by region. Private prescribing is also available through registered online services following a clinical 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.