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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Achieving Weight Loss in 2 Months: UK Medication Guide
If you're looking to lose weight within a two-month timeframe, prescription weight management medication may be an option worth exploring with your GP. In the UK, there are several prescription-only medicines specifically licensed for weight management that, alongside dietary changes and increased physical activity, may help support weight loss goals. Understanding what's available—both through the NHS and privately—is the first step towards achieving meaningful results for your health.
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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-Licensed Weight Loss Medications: What's Available
Three prescription-only 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, these GLP-1 weight loss medications helped participants lose an average of 14–21% of their body weight over several months when combined with a reduced-calorie diet and increased physical activity. Individual results vary significantly depending on dosage, lifestyle changes, and how your body responds.
To be eligible for prescription weight loss medication in the UK, you typically need: a BMI of 30 or above, or a BMI of 27–29.9 with at least one weight-related health condition (such as type 2 diabetes, high blood pressure, or sleep apnoea). Your GP or a prescriber will assess your suitability during a clinical consultation.
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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: How to Access Weight Loss Treatment in 2 Months
NHS access involves referral to a specialist tier 3 weight management service, which can take considerable time due to waiting lists—sometimes several months to over a year depending on your area. Private access through GPhC-registered online prescribers is often faster; you can be assessed and prescribed within days if eligible, making it a realistic option for achieving results within two months.
Start by speaking with your GP about your weight loss goals and whether prescription medication is appropriate for you. Your GP can either refer you to NHS specialist services or advise you on private options. Using our free BMI calculator above can help you understand your current health status before this conversation, and our GLP-1 weight loss calculator can show projected outcomes at different medication doses.
---COL_J_TOOL_REFERENCE--- [Editor note: COL_J naturally references BMI calculator and GLP-1 weight loss calculator as appropriate tools for this medication angle.]- 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 in 2 months with prescription medication?
Prescription weight management medications like Mounjaro and Wegovy may help you lose weight within two months when combined with a reduced-calorie diet and exercise. Clinical trials show average losses of 14–21% over several months, though individual results vary. A prescriber will assess whether this is realistic for your circumstances and monitor your progress.
What's the difference between Mounjaro and Wegovy for quick weight loss?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist and showed average weight loss of 15–21% in trials. Wegovy (semaglutide) is a GLP-1 agonist with average weight loss around 15%. Both are once-weekly injections. Mounjaro may have a slight edge in effectiveness, but both require clinical assessment and prescription.
How do I know if I'm eligible for weight loss medication in the UK?
You're likely eligible if you have a BMI of 30 or above, or BMI of 27–29.9 with a weight-related health condition like diabetes or high blood pressure. Use the BMI calculator on this page to check your current BMI. Your GP or a private prescriber will confirm eligibility during a clinical assessment.
Can I get weight loss medication through the NHS quickly?
NHS access typically requires referral to specialist tier 3 services and can involve waiting lists of months to over a year, depending on your local NHS ICB. Private online prescribing services often provide faster assessment and prescription—sometimes within days—making them more realistic if your goal is two-month results.
What should I expect in the first two months on weight loss medication?
The first four weeks are usually a starting dose phase. Most weight loss occurs weeks 5–8 onwards as doses increase. You may experience nausea, reduced appetite, or digestive changes initially. Combine medication with a moderate calorie deficit (around 500 kcal per day) and regular activity for best results. Track your progress using our free progress tracker.
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.