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
Does Smoking Help In Weight Loss?
No, smoking does not help with sustainable weight loss and carries serious health risks. While some smokers experience lower body weight, nicotine's appetite-suppressing effects are temporary and come at a significant cost to your health. If you're interested in weight management in the UK, prescription medication and lifestyle approaches are far safer and more effective options available through your GP or private prescribing services.
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.
Why Smoking Isn't a Weight Loss Solution
Smoking may temporarily reduce appetite due to nicotine stimulating the nervous system, but this effect is short-lived and comes with serious health consequences. Smokers often weigh less initially, but this masks underlying health damage including increased risk of heart disease, stroke, cancer, and type 2 diabetes.
The NHS emphasises that any perceived weight loss from smoking is outweighed by the damage to your cardiovascular and respiratory systems. Additionally, many smokers gain weight when they quit because they substitute smoking with food — this is normal and manageable with proper support.
For effective weight management in the UK, evidence-based approaches include prescription medications like Mounjaro or Wegovy, dietary changes, and physical activity — all without the health risks associated with smoking.
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.
UK-Licensed Weight Loss Medication Options
If you're struggling with your weight, several prescription options are available through the NHS or private prescribing. Mounjaro (tirzepatide) and Wegovy (semaglutide) are GLP-1 receptor agonists that help regulate appetite and support weight loss without any of smoking's risks. Clinical trials show these medications can help participants lose 15–21% of body weight on average when combined with lifestyle changes.
To find out if you're eligible for prescription weight loss medication, speak with your GP about your BMI and any weight-related health conditions. Eligibility typically includes adults with a BMI of 30 or above, or BMI of 27 or above with conditions like type 2 diabetes or high blood pressure. You can use our free BMI calculator to check your starting point, and our GLP-1 weight loss calculator can show you potential outcomes at different medication doses.
- 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.
Does smoking actually make you lose weight?
Nicotine can temporarily suppress appetite, which may lead to lower food intake in the short term. However, any weight loss is minimal and comes with serious health risks including heart disease, stroke, and cancer. This approach is never recommended by the NHS or health professionals.
What are the real health risks of smoking for weight loss?
Smoking damages your lungs, heart, and blood vessels; dramatically increases cancer risk (13 types linked); worsens type 2 diabetes; and reduces life expectancy by up to 10 years. The temporary appetite suppression is vastly outweighed by these dangers.
What's the best way to lose weight safely in the UK?
The NHS recommends a combination of reduced-calorie diet, increased physical activity, and behavioural support. For eligible adults, prescription weight loss medications like Mounjaro or Wegovy — available through NHS specialist services or private prescribing — offer clinically proven results alongside lifestyle changes.
Will I gain weight if I quit smoking?
Some weight gain is common when quitting smoking because nicotine suppression ends. However, this is manageable through balanced diet and exercise. The health benefits of quitting far outweigh any modest weight gain, and prescription weight loss options are available if needed.
How do I know if I'm eligible for prescription weight loss treatment in the UK?
Adults with a BMI of 30 or above (or 27+ with weight-related health conditions like diabetes or hypertension) may be eligible. Check your BMI using our free BMI calculator, then speak with your GP about NHS referral to specialist services or explore private prescribing options.
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.