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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Sweating and Weight Loss: What You Need to Know
Sweating during weight loss is a common experience for many UK adults, particularly when combining diet and exercise with prescription weight management medication. This guide explains why sweating happens, how it relates to your body's metabolism, and what prescription weight loss options are available if you're eligible. If you're considering medication to support your weight management journey, understanding both the process and your options is essential.
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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 Medications
Three prescription medications are currently licensed in the UK for weight management in eligible adults:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist, injected once weekly. Clinical trials showed an average weight loss of approximately 15–21% of body weight alongside diet and exercise changes.
- Wegovy (semaglutide) — a GLP-1 receptor agonist, injected once weekly. Evidence suggests average weight loss of around 14.9% of body weight in clinical trials.
- Saxenda (liraglutide) — a GLP-1 receptor agonist, injected daily. Approved for weight management in UK adults with a BMI of 30 or above, or 27 or above with weight-related health conditions.
All three medications are prescription-only and require a clinical assessment before being prescribed. Individual results vary significantly, and these medications are most effective when combined with a reduced-calorie diet and increased physical activity. Use our free GLP-1 weight loss calculator to explore potential outcomes at different doses.
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.
Accessing Weight Loss Medication: NHS vs Private Routes
In the UK, you can access prescription weight management medication through two main pathways. The NHS route involves referral from your GP to a specialist tier 3 weight management service. Eligibility typically requires a BMI of 30 or above with weight-related health conditions, or 35 or above without comorbidities. NHS availability varies by region and waiting lists can be lengthy. The private route offers access through online consultations with UK-licensed prescribers, typically faster and without NHS referral requirements, though medication costs are not covered by the NHS. Speak with your GP about your eligibility and preferred route to explore what's available to you.
- 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.
Why do people sweat more during weight loss?
Increased sweating during weight loss occurs due to changes in metabolism, hormonal shifts, and your body's temperature regulation. When you reduce calories or begin losing weight, your metabolic rate adjusts, and your body may increase sweat production to maintain temperature balance. This is a normal physiological response, though individual experiences vary.
Does prescription weight loss medication like Mounjaro or Wegovy cause sweating?
Sweating is not listed as a common side effect of Mounjaro or Wegovy in clinical trials. However, some users report night sweats or increased perspiration, particularly during the initial weeks of treatment. If you experience excessive or concerning sweating after starting medication, inform your prescriber. Most weight loss-related sweating is due to the weight loss process itself rather than the medication.
What's my BMI and am I eligible for prescription weight loss treatment in the UK?
Use our free BMI calculator on this page to check your personal BMI instantly. UK eligibility for prescription weight loss medication typically requires a BMI of 30 or above, or 27 or above with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. Your GP can confirm whether you meet NHS criteria or discuss private options.
How can I access weight loss medication through the NHS in the UK?
Start by speaking with your GP about weight management support. If you're eligible, your GP can refer you to a specialist tier 3 weight management service in your local area. These services assess your suitability for prescription medications like Mounjaro or Wegovy. Waiting times vary by region, so discussing referral timelines with your GP is helpful.
What should I do if I want to explore weight loss medication options?
First, calculate your BMI using our free BMI calculator to understand your starting point. Then speak with your GP about your weight management goals and eligibility for prescription options. Your GP can explain both NHS and private routes, discuss potential medications, and help you decide the best approach for your individual health needs and circumstances.
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.