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
Beginner Workout Weight Loss & UK Medication Options
Starting a beginner workout routine is an excellent step towards sustainable weight loss. In the UK, many adults combine exercise with prescription weight management medication to achieve better results. This guide covers UK-licensed options available to eligible adults, how the medication works alongside your fitness routine, and how to find out if you qualify through the NHS or private prescribing. Weight loss is most effective when combining physical activity with professional support—whether that's from a GP or a licensed prescriber.
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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 Prescription Weight Loss Medications & Eligibility
Three prescription 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. These are GLP-1 receptor agonists (or in Mounjaro's case, a dual GIP/GLP-1 agonist) that help reduce appetite and support feeling fuller after smaller meals.
To be eligible for prescription weight loss medication in the UK, you typically need a BMI of 30 or above, or 27 or above with a weight-related health condition such as type 2 diabetes, high blood pressure, or sleep apnoea. Use our free BMI calculator above to check your personal BMI. Clinical trials show that patients on these medications, combined with reduced-calorie diet and increased physical activity, lost an average of 15–21% of their body weight over 68–72 weeks—though individual results vary significantly. These are prescription-only medicines requiring a clinical assessment before prescribing.
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.
Getting Started: NHS vs Private Access in the UK
In the UK, prescription weight loss medication is available through two routes: NHS specialist weight management services or private online prescribing. NHS access typically requires a referral from your GP to a tier 3 or tier 4 weight management service, though availability varies widely by region and waiting times can be lengthy. Private access is available through GPhC-registered online pharmacies following an online clinical assessment—no NHS referral required.
Whichever route you choose, medication works best alongside your beginner workout routine and dietary changes, not instead of them. Your GP or prescriber can assess whether medication is suitable for you and help you track progress. Try our free GLP-1 weight loss calculator to estimate potential results at different medication doses, and use our progress tracker to monitor your weight loss journey as you combine exercise and professional support.
- 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 take prescription weight loss medication as a beginner starting exercise?
Yes, if you're eligible. Prescription medications like Mounjaro and Wegovy work best combined with physical activity and diet changes. Your prescriber will assess whether medication is suitable for you. Exercise should always be appropriate to your fitness level—starting slowly as a beginner is sensible.
How much weight can I expect to lose with medication and a beginner workout?
Clinical trials showed an average of 15–clinically studied weight loss with medication, alongside diet and exercise. However, individual results vary significantly. Your actual weight loss depends on your starting weight, adherence to medication, diet, and exercise consistency. Use our weight loss calculator for a personalised estimate.
How do I find out if I'm eligible for prescription weight loss medication on the NHS?
Speak to your GP about weight management options. They can assess your BMI, health conditions, and medical history. If eligible, you may be referred to a specialist NHS tier 3 weight management service. Availability varies by region—waiting times can be several months in some areas.
What's the difference between Mounjaro, Wegovy, and Saxenda?
Mounjaro (tirzepatide) is a dual GIP/GLP-1 agonist, once-weekly injection. Wegovy (semaglutide) is a GLP-1 agonist, once-weekly injection. Saxenda (liraglutide) is a GLP-1 agonist, daily injection. All are prescription-only. Clinical evidence shows all three support weight loss, though individual response varies.
Can I stop taking weight loss medication once I've reached my goal with exercise and diet?
This is a question for your prescriber. Some people maintain weight after stopping medication, others regain weight. Your GP or prescriber can discuss long-term management, whether that's continuing medication, stopping with ongoing lifestyle support, or other approaches suited to your individual circumstances.
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.