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
Weight Loss and Sweating at Night — Understanding Your Options
Night sweats can occur during weight loss, particularly when using prescription weight loss medication or losing weight quickly. In the UK, adults managing their weight through prescription options like GLP-1 injections may experience this side effect alongside other common reactions. Understanding what's normal, when to contact your GP, and what prescription weight management options are available can help you make informed decisions about your health. MyWeightCheck provides free tools to support your weight loss journey and help you track progress.
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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 Prescription Weight Loss Medication Options
If you're experiencing night sweats whilst pursuing weight loss in the UK, prescription medication may be part of your approach. Three main prescription weight loss options are licensed in the UK:
- Mounjaro (tirzepatide) — a once-weekly dual GIP/GLP-1 injection. Clinical trials showed average weight loss of 15–21% of body weight. Common side effects include nausea and sweating, though these often improve over time.
- Wegovy (semaglutide) — a once-weekly GLP-1 injection with average weight loss around 15% of body weight in clinical trials. Side effects profile similar to Mounjaro.
- Saxenda (liraglutide) — a daily GLP-1 injection, less commonly prescribed but still available through NHS weight loss services and private prescribing.
All three are prescription weight loss medication requiring clinical assessment. Night sweats are not listed as very common side effects for any of these, but sweating and temperature changes may occur as your body adjusts to gradual weight management.
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 and Eligibility in the UK
In the UK, weight management through prescription medication is available through two pathways:
- NHS: Referral to a specialist tier 3/4 weight management service. Eligibility typically requires BMI ≥30, or ≥27 with weight-related health conditions (type 2 diabetes, high blood pressure, sleep apnoea). Regional availability varies significantly — waiting lists can be several months to years.
- Private: Online consultation with a UK-licensed prescriber. Faster access but costs typically £129–£320/month depending on dose. Still requires clinical assessment and prescription.
Night sweats during weight loss medication use should always be reported to your prescriber. Use our free GLP-1 weight loss calculator to explore projected results, and our BMI calculator to understand your personal eligibility thresholds.
- 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.
Can prescription weight loss medication cause night sweats?
Night sweats are not listed as a very common side effect of Mounjaro, Wegovy, or Saxenda. However, any medication affecting metabolism and appetite can cause temperature changes in some individuals. Sweating during gradual weight management is also normal as your body adjusts. Always report unusual symptoms to your prescriber.
When should I contact my GP about night sweats during weight loss?
Contact your GP if night sweats are severe, persistent, accompanied by fever or chills, disrupting your sleep significantly, or occurring alongside other concerning symptoms. If you're on prescription weight loss medication, inform your prescriber. Your GP can rule out other causes and advise whether to continue or adjust your treatment.
Are night sweats a reason to stop weight loss medication?
Not necessarily. Mild sweating often improves as your body adjusts to medication. However, only your prescriber can advise whether to continue, adjust dose, or switch medication. Never stop prescription medication without medical guidance. Always discuss symptoms at your follow-up appointments.
How quickly should I expect to lose weight on UK prescription medication?
Individual results vary significantly. Clinical trials showed average weight loss of 15–21% body weight over several months on Mounjaro, and around 15% on Wegovy. Safe weight loss is typically 0.5–1 kg per week. Our free weight loss calculator can help you estimate potential progress based on your starting point.
What's the difference between NHS and private weight loss medication access in the UK?
NHS access requires GP referral to specialist services and depends on regional funding. Waiting lists are often lengthy. Private access is faster through online prescribing but involves costs. Both require clinical assessment. Neither is "better" — the right choice depends on your circumstances, timeline, and budget.
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.