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
Over Counter Weight Loss Options in the UK
Many people searching for "over counter weight loss" are looking for readily available products they can buy without a prescription. The truth is that effective weight loss medications in the UK are prescription-only — including popular options like Wegovy (semaglutide) and Mounjaro (tirzepatide). However, there are NHS-supported pathways and other weight management approaches available. This guide explains your options for weight management in the UK, from self-help resources to prescription weight loss medication accessed through your GP or private prescribers.
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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.
Why Prescription Weight Loss Medications Are More Effective Than Over-the-Counter Products
In the UK, prescription weight loss injections have been clinically proven to help with sustainable weight loss. Wegovy (semaglutide) is a GLP-1 receptor agonist that, in clinical trials, helped participants lose an average of 15% of their body weight alongside diet and exercise. Mounjaro (tirzepatide), a dual GIP and GLP-1 agonist, showed average weight loss of 15–21% in clinical trials.
Over-the-counter weight loss products sold in the UK — such as supplements, herbal tablets, or meal replacement shakes — do not undergo the same rigorous clinical testing or regulatory oversight as prescription medications. While some may offer modest support for weight management as part of a broader lifestyle approach, none have demonstrated the level of evidence that prescription medications have.
Weight loss medication in the NHS is accessed through specialist tier 3 weight management services, typically following GP referral. Private prescription weight loss medication is available through UK-licensed prescribers following an online clinical assessment.
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.
How to Access Weight Loss Support in the UK
The NHS weight loss pathway starts with your GP. You can discuss weight management options, and if suitable, be referred to a specialist weight management service in your area. Waiting times vary significantly by region, and not all areas have the same level of provision.
For those seeking faster access, prescription weight loss medication is available privately through GPhC-registered online prescribers. These services conduct an online clinical assessment to determine if prescription weight loss treatment is appropriate for you based on your BMI, health conditions, and medical history.
Use our free BMI calculator to check where your weight falls, and try our GLP-1 weight loss calculator to understand potential outcomes with different medication doses. Combined with the weight converter tool, you can track your progress in both kg and stone.
- 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.
Are there any weight loss products I can buy without a prescription in the UK?
Yes, there are many over-the-counter weight loss supplements, herbal products, and meal replacement shakes available. However, these typically have less robust clinical evidence than prescription medications. Always check the label, and discuss any new supplement with your GP, especially if you take other medications.
What is the difference between Wegovy and Ozempic?
Both contain semaglutide, but Wegovy is licensed specifically for weight management (up to 2.4 mg), while Ozempic is licensed for type 2 diabetes (up to 2 mg). Using Ozempic for weight loss is off-label. Wegovy is the prescription weight loss medication available in the UK.
Can I get prescription weight loss medication on the NHS?
Yes. NHS access is through specialist tier 3 weight management services, typically following a GP referral. Eligibility requires a BMI of 30 or above, or 27 or above with weight-related health conditions. Availability and waiting times vary by region and ICB.
How much weight can I expect to lose with prescription medication?
Clinical trials show average weight loss of 15–21% of body weight with GLP-1 and GIP/GLP-1 medications, alongside reduced-calorie diet and physical activity. Individual results vary significantly — some people lose less, some more. A prescriber can discuss realistic expectations based on your personal situation.
What should I do first if I want to lose weight?
Start by checking your BMI using our free BMI calculator to understand where you stand. Then speak to your GP about weight loss options suitable for you. Your GP can discuss lifestyle changes, tier 1 support (digital tools, weight loss programmes), and whether specialist referral or prescription medication might help.
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.