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
Can You Drink Tea While Taking Mounjaro?
Yes, you can drink tea while taking Mounjaro — there are no known interactions between tea and tirzepatide. However, if you experience nausea or stomach sensitivity (common Mounjaro side effects), hot drinks like tea might worsen these symptoms temporarily. Most people tolerate tea well on Mounjaro, but it's worth monitoring how your body responds. If you have specific concerns about your diet or medications while using this prescription weight loss injection, always discuss them with your GP or the prescriber managing your treatment through NHS specialist services or private clinical assessment.
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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.
Tea and Mounjaro: What You Need to Know
Tea is safe to drink on Mounjaro — there are no direct interactions between tea (including caffeine) and tirzepatide. Mounjaro works as a dual GIP and GLP-1 receptor agonist to help regulate appetite and blood sugar, and tea does not interfere with these mechanisms. However, during the first few weeks of Mounjaro treatment or when dose titration increases, some people experience nausea, indigestion, or reduced appetite as side effects. In these cases, very hot tea or large volumes of liquid might temporarily aggravate stomach discomfort. Practical tips: if nausea is present, try lukewarm or cool tea instead; drink tea slowly rather than in large gulps; avoid tea immediately before or after your weekly injection; ginger tea may actually help settle nausea for some people. Always follow guidance from your prescriber — whether through NHS tier 3 specialist services or private assessment — if you're uncertain about any food or drink.
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.
Caffeine, Hydration, and Mounjaro
Caffeine itself does not interact with Mounjaro, so regular tea, green tea, and coffee are all safe. However, Mounjaro can slow gastric emptying (how quickly food and liquid leave your stomach), which may make you feel fuller longer — this is intentional and part of how the medication works. Stay hydrated by drinking plenty of water throughout the day, as dehydration can worsen nausea and constipation (both possible side effects). Some people find that spreading drinks throughout the day rather than consuming large volumes at once is more comfortable when taking tirzepatide. If you're using Mounjaro as part of your weight loss journey tracked through our GLP-1 weight loss calculator, remember that weight management success depends on combining the injection with dietary changes and increased physical activity — your drink choices support this holistic approach.
- 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.
Will tea affect how Mounjaro works?
No. Tea and caffeine do not interact with tirzepatide or interfere with how Mounjaro works. You can safely drink tea throughout your treatment. If you experience nausea during the first few weeks, adjusting the temperature or volume of tea may help, but the tea itself is safe.
What drinks should I avoid on Mounjaro?
There are no drinks absolutely forbidden on Mounjaro. However, some people find that sugary drinks, very hot beverages, or large volumes of liquid worsen nausea temporarily. Water is always the best choice. Avoid consuming alcohol in excess, as this can increase dehydration and nausea risk. Check with your GP if you have concerns.
Can I drink caffeine with Mounjaro?
Yes, caffeine is safe on Mounjaro. Tea, coffee, and other caffeinated drinks do not interact with tirzepatide. If caffeine makes you jittery or worsens nausea, reduce your intake — but this is about personal tolerance, not a Mounjaro-specific restriction.
Does Mounjaro affect how my body processes drinks?
Mounjaro slows gastric emptying, meaning food and liquids leave your stomach more slowly. This is intentional and helps create fullness. You may feel satisfied after smaller amounts of liquid. Staying hydrated remains important — drink water regularly, even if you feel less thirsty than usual.
Should I take Mounjaro with or without tea?
You can take your weekly Mounjaro injection at any time of day regardless of whether you've had tea. There is no specific timing requirement related to tea or other drinks. However, if nausea is present on injection day, some people prefer to inject when the stomach is calm and drink less until nausea settles.
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.