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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Low Dose Mounjaro in the UK: Cost and Access
Starting Mounjaro (tirzepatide) at a low dose is the standard approach in the UK, with most adults beginning at 2.5 mg once weekly. If you're considering this prescription weight management option, understanding both NHS and private access routes is essential. The cost and availability of low dose Mounjaro varies significantly depending on whether you access it through the NHS or via private prescription following an online clinical assessment. This guide explains your options, typical costs, and what to expect from each route.
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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 Private Prescription Costs for Low Dose Mounjaro
Private access to low dose Mounjaro (2.5 mg) in the UK typically costs £120–£180 per month, though prices vary between GPhC-registered pharmacies. Each KwikPen contains four weekly doses, so one pen lasts approximately one month at the starting dose. When you progress to higher doses during dose titration (increasing your dose every 4 weeks), the cost may increase—5 mg doses typically cost £150–£200 monthly. Private prescriptions require an online clinical assessment with a UK-licensed prescriber, which usually costs £20–£50 and must be completed before dispensing. Unlike NHS prescriptions, private costs are not subject to the prescription charge and you pay the full price set by the pharmacy. Some providers offer subscription discounts if you commit to multiple months upfront. It's worth comparing prices across registered providers, though all should follow the same safety and quality standards.
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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 Routes
NHS route: Low dose Mounjaro is available through specialist tier 3 weight management services following GP referral, but availability is highly variable by region. Waiting lists can extend several months or longer in many areas, and access depends on meeting NICE eligibility criteria (BMI 30+ or 27+ with weight-related conditions). Once approved, NHS prescriptions cost the standard prescription charge (currently £9.90 in England) regardless of dose.
Private route: Available immediately following an online assessment with no referral needed. You'll complete a health questionnaire and video or phone consultation with a prescriber, then receive your prescription to a GPhC-registered pharmacy. Private access suits those who cannot wait for NHS services or prefer faster initiation alongside our GLP-1 weight loss calculator to track projected outcomes.
- 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 I start on a low dose of Mounjaro (2.5 mg)?
The 2.5 mg starting dose allows your body to adjust to tirzepatide and helps identify any side effects early. After 4 weeks, if tolerated well, your prescriber increases the dose gradually. This dose titration schedule (2.5 → 5 → 7.5 mg and so on) is standard practice in the UK and reduces nausea and digestive side effects compared to starting higher.
Is low dose Mounjaro as effective as higher doses?
Clinical trials show that weight loss increases with higher doses of tirzepatide. The 2.5 mg starting dose is lower in efficacy than 15 mg, but it's necessary for safety and tolerability. Most people progress to 5–10 mg within 8–12 weeks, where meaningful weight loss typically becomes evident. Results vary individually.
Can I get low dose Mounjaro on the NHS quickly?
NHS access involves referral to a specialist weight management service, which can take weeks to months depending on your region and local waiting lists. Some ICBs have very long delays. NICE has approved tirzepatide for NHS use, but availability remains patchy. Private prescription is faster if you need to start immediately.
What's included in the private consultation cost?
A private online consultation (£20–£50) includes a health questionnaire review, discussion of your weight loss goals, assessment of eligibility, and medical history screening. The prescriber checks for contraindications and drug interactions. If approved, they issue a prescription to your chosen GPhC-registered pharmacy; if not suitable, they'll explain why and may suggest alternatives.
Can I use the progress tracker to monitor my low dose results?
Yes—our free progress tracker helps you log your weight weekly and visualise trends over weeks and months. Starting at 2.5 mg, changes may be subtle in the first 4 weeks, but tracking consistently shows whether you're progressing toward your goal before your dose increases at week 4.
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.