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 With Weight Loss?
No — smoking does not help with sustainable weight loss and poses serious health risks. While nicotine may temporarily suppress appetite, the health damage from smoking far outweighs any minor weight-related effect. If you're looking to lose weight safely in the UK, evidence-based approaches like dietary changes, physical activity, and prescription weight loss medication (where clinically appropriate) are far more effective and sustainable than smoking.
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 Doesn't Support Healthy Weight Loss
Although nicotine is a stimulant that can temporarily reduce appetite, relying on smoking for weight management is harmful and ineffective long-term. Here's why:
- Temporary appetite suppression only: Nicotine's appetite-suppressing effect is short-lived and fades with continued use as your body develops tolerance.
- Smoking causes weight gain after quitting: Most people gain weight when they stop smoking because their metabolism normalises and appetite returns — meaning smoking creates a false weight management scenario.
- Serious health risks: Smoking significantly increases risk of heart disease, stroke, cancer, COPD, and type 2 diabetes — diseases that are actually worsened by excess weight.
- Undermines metabolic health: Smoking damages lung function and circulation, which impairs your body's ability to exercise and burn calories effectively.
- Costs money: A typical smoking habit costs £3,000–£4,000 per year in the UK — money that could support evidence-based weight loss approaches instead.
The NHS is clear: smoking is never a weight management strategy. If you smoke and want to lose weight, quitting smoking while pursuing sustainable weight loss is the healthiest approach.
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.
Evidence-Based Weight Loss Alternatives
If you're overweight and considering any method to lose weight, the NHS recommends proven approaches that actually work:
- Calorie deficit through diet: A reduction of 500 kcal per day typically results in approximately 0.5 kg loss per week — sustainable and safe.
- Increased physical activity: Aim for 150 minutes of moderate activity weekly. Use our free BMI calculator to check your current weight status and set realistic goals.
- Prescription weight loss medication: For adults with a BMI of 30 or above (or 27+ with weight-related conditions), medications like GLP-1 injections are available through NHS specialist services or private prescribing. Our GLP-1 weight loss calculator can help you estimate potential outcomes at different doses.
- Behavioural support: Weight management services across the UK offer structured programmes combining diet, exercise, and psychological support.
All of these approaches have evidence supporting them — smoking does not.
- 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 nicotine speed up metabolism and help with weight loss?
Nicotine is a stimulant that can slightly increase heart rate and metabolism, but the effect is minimal and temporary. Your body quickly adapts (tolerance develops), so any metabolic boost diminishes with continued use. This is far too small to support meaningful weight loss and comes with serious health risks.
What happens to weight when someone stops smoking?
Most people gain 4–5 kg (9–11 lbs) on average after quitting smoking, typically within the first few months. This happens because metabolism normalises and appetite returns to baseline. However, long-term health benefits of quitting far outweigh temporary weight gain — your GP can discuss weight management support whilst you quit.
Can I lose weight while smoking?
Yes, you can lose weight through diet and exercise while smoking, but smoking actively works against weight loss by reducing lung capacity, impairing circulation, and increasing disease risk. Quitting smoking removes a major barrier to effective weight loss and significantly improves your overall health outcomes.
Is there a link between smoking and weight management on the NHS?
The NHS clearly advises against smoking for any health reason, including weight management. If you want to lose weight and currently smoke, NHS services can support both goals — your GP can refer you to smoking cessation services and weight management programmes simultaneously.
What's the safest way to lose weight in the UK without smoking?
Evidence-based methods include: a calorie deficit of 500 kcal daily (for ~0.5 kg/week loss), 150 minutes weekly physical activity, and if eligible, prescription weight loss treatment. For personalised advice, consult your GP. Our free BMI calculator above helps you understand your current weight category and set realistic targets.
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.