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
Hypnotherapy for Weight Loss — UK Prescription Alternatives
Hypnotherapy is sometimes explored as a complementary approach to weight management, though evidence for standalone hypnotherapy remains limited. If you're interested in clinically proven weight management options in the UK, prescription medications are available for eligible adults. This guide covers evidence-based prescription weight loss treatments and how to access them through the NHS or privately, alongside lifestyle changes.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Medications
For adults looking for clinically supported weight management in the UK, three prescription medications are currently licensed by the MHRA:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist, injected once weekly. Clinical trials showed participants lost an average of 15–21% of their body weight alongside reduced-calorie diet and increased physical activity.
- Wegovy (semaglutide) — a GLP-1 receptor agonist, injected once weekly. Clinical trials demonstrated average weight loss of approximately 15% of body weight over 68 weeks.
- Saxenda (liraglutide) — a GLP-1 receptor agonist, injected once daily. Offers a daily injection alternative for eligible adults.
Eligibility includes adults with a BMI of 30 or above, or 27 or above with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. Individual results vary, and prescription weight loss medication works best alongside lifestyle changes, not as a replacement for them. Use our free BMI calculator above to check if you may fall within eligible ranges.
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 — How to Find Out if You're Eligible
NHS access: Available through tier 3 specialist weight management services following a GP referral. Availability varies significantly by region (Integrated Care Board), and waiting lists can be lengthy. Contact your GP to discuss referral to your local specialist weight management service.
Private access: Available through online prescribing services following a confidential clinical assessment with a UK-licensed prescriber. No NHS referral required, though costs typically range from £129–£320 per month depending on dose.
Whichever route you explore, your prescriber will assess your individual health, medical history, and eligibility. Try our GLP-1 weight loss calculator to explore potential outcomes at different doses, and use our weight converter and BMI calculator to understand your current health metrics.
- 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.
Is hypnotherapy proven to work for weight loss?
Hypnotherapy has limited robust clinical evidence for weight loss. Some studies suggest modest benefits for behavioural support, but results are not comparable to NHS-licensed prescription medications. If you're looking for evidence-based options, prescription weight loss medications have strong clinical trial support and are available in the UK for eligible adults.
What's the difference between Mounjaro and Wegovy for weight loss?
Both are once-weekly injections, but they work slightly differently. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, while Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials show Mounjaro may produce slightly greater average weight loss, though individual results vary significantly. Your prescriber will assess which suits you best.
Can I get prescription weight loss medication on the NHS?
Yes, through specialist tier 3 weight management services. You'll need a GP referral, and eligibility is assessed based on BMI and health conditions. Availability and waiting times vary by region. Contact your GP to discuss referral options in your area.
How quickly does prescription weight loss medication work?
Weight loss typically becomes noticeable within 4–8 weeks, with more significant results over 3–6 months. Doses are increased gradually (every 4 weeks), and reaching maximum dose takes 16–20 weeks. Results are achieved alongside a reduced-calorie diet and increased physical activity.
What happens if I stop taking prescription weight loss medication?
Weight loss is not permanent once you stop the medication — weight often returns if lifestyle changes are not maintained. Prescription medication is typically used for 12 months or longer, alongside sustained diet and exercise changes. Your prescriber will discuss long-term plans with you during treatment.
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.