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 Tea and Prescription Alternatives in the UK
While many detox and weight loss teas are marketed for rapid results, evidence for their effectiveness is limited. If you're looking for weight management support in the UK, there are prescription options with proven clinical evidence available through NHS services or private prescribing. This guide explores how prescription weight loss medication compares to supplements and teas, helping you understand what's genuinely effective for sustainable weight loss.
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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
For adults seeking evidence-based weight management in the UK, three prescription medications are licensed for weight loss: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). These are GLP-1 receptor agonists—injectable medications that work by regulating appetite and helping you feel fuller after smaller meals.
Clinical trials show significant results: Mounjaro users lost an average of 15–21% of body weight, while Wegovy users achieved approximately clinically studied weight loss. Both are once-weekly injections prescribed following a clinical assessment. Saxenda is a daily injection alternative. Unlike supplements or teas, these prescription medications are regulated by the MHRA and backed by rigorous clinical trials.
You can calculate your BMI using our free BMI calculator to see if you might meet eligibility criteria (typically BMI 30 or above, or 27+ with weight-related health conditions). Prescription weight loss medication works best alongside lifestyle changes like reduced-calorie diet and increased physical activity.
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 to Weight Loss Medication
NHS route: Referral to a tier 3 specialist weight management service through your GP. Access varies significantly by region and waiting times can be lengthy. This is the funded option if you're eligible.
Private route: Online consultation with a UK-licensed prescriber followed by dispensing through a GPhC-registered pharmacy. Available without NHS referral and typically faster access, though costs apply (generally £129–£320 monthly depending on dose). Both routes require a prescription and clinical assessment—detox teas require neither, but also lack proven efficacy for meaningful weight loss.
Track your weight loss progress using our free progress tracker, whether you choose prescription medication, dietary changes, or a combination approach. The most sustainable weight loss combines evidence-based treatment with consistent lifestyle adjustment.
- 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 detox teas actually help me lose weight?
Most detox teas lack strong clinical evidence for weight loss. They may have mild diuretic effects causing temporary water loss, but this isn't sustainable fat loss. Prescription medications like Mounjaro and Wegovy have proven clinical trial data showing 15–21% body weight reduction when combined with lifestyle changes.
How do I know if I'm eligible for prescription weight loss medication in the UK?
You may be eligible if your BMI is 30 or above, or 27–29.9 with weight-related conditions like type 2 diabetes, high blood pressure, or sleep apnoea. Use our free BMI calculator to check your starting point, then discuss eligibility with your GP or a licensed prescriber through private consultation.
What's the difference between NHS and private prescription weight loss in the UK?
NHS access is through specialist tier 3 services (referral from GP, may involve waiting lists) and is funded. Private access is through online prescribing consultations with UK-licensed prescribers and GPhC pharmacies, faster but costs apply. Both require prescription and clinical assessment.
How quickly will prescription weight loss medication work compared to tea or supplements?
Prescription medications show measurable results within weeks, with average losses of 0.5–1 kg per week. Clinical trials tracked results over 68–72 weeks showing 15–21% total body weight loss. Detox teas rarely produce meaningful, sustained weight loss and lack this level of clinical evidence.
Can I use weight loss medication without changing my diet and exercise habits?
Prescription weight loss medications work best alongside lifestyle changes—reduced-calorie diet and increased physical activity. Clinical trial results were achieved with these combined approaches. The medication supports appetite regulation, but sustainable weight management requires commitment to healthier habits.
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.