Mounjaro
Mounjaro (tirzepatide) has helped thousands of people in the UK achieve significant weight loss, but like any prescription medicine, it can cause side effects — particularly in the first few weeks.
This pharmacist-reviewed guide explains the most common reactions, how to manage them, and when to seek professional advice.
Why Mounjaro Causes Side Effects
Mounjaro works by mimicking two natural hormones — GLP-1 and GIP — which slow digestion, regulate appetite, and control blood sugar.
As your body adjusts, the digestive system temporarily slows down, which can lead to nausea or stomach discomfort.
These effects usually improve as treatment continues.
Common Mounjaro Side Effects (Usually Mild & Temporary)
| Symptom | When It Happens | What to Do |
|---|---|---|
| Nausea | First few weeks | Eat smaller meals, avoid greasy food, and stay hydrated. |
| Heartburn or indigestion | Early stages | Avoid spicy foods and caffeine. Consider small, frequent meals. |
| Constipation | Ongoing | Increase fibre intake and water; gentle exercise can help. |
| Diarrhoea | Occasionally after dose increase | Stay hydrated; contact your pharmacist if persistent. |
| Tiredness or dizziness | Early phase | Rest and maintain steady blood-sugar levels by not skipping meals. |
Most people find these symptoms ease after 2–4 weeks, especially once their body adapts to the starting dose.
Less Common Side Effects
- Mild injection-site irritation or redness
- Burping or bloating
- Slight decrease in appetite or altered taste
These are usually harmless and resolve on their own.
Serious but Rare Side Effects
Seek medical advice immediately if you notice:
- Severe or ongoing stomach pain (possible pancreatitis)
- Persistent vomiting or dehydration
- Signs of allergic reaction (swelling, rash, shortness of breath)
- Yellowing of skin or eyes (possible liver issue)
While rare, these require prompt attention. If you’re unsure, call NHS 111 or seek emergency help.
How to Reduce Mounjaro Side Effects
- Follow your titration plan – only increase dose every 4 weeks under prescriber guidance.
- Eat slowly – smaller bites help digestion.
- Avoid overeating – Mounjaro works best with moderate portions.
- Stay hydrated – aim for 1.5–2 litres of water daily.
- Be consistent – inject on the same day each week to stabilise hormone levels.
When to Contact a Pharmacist or Doctor
- If nausea or constipation last more than two weeks.
- If you develop new symptoms after increasing your dose.
- If you take other medicines (especially for diabetes or hypertension) that might interact.
At PPRX Online Pharmacy, our pharmacists provide confidential support to help manage your treatment safely.
Mounjaro KwikPen Information
Each Mounjaro KwikPen provides four once-weekly doses — a 4-week supply.
| Strength | Duration | Price |
|---|---|---|
| 2.5 mg | 4 weeks | £215 |
| 5 mg | 4 weeks | £235 |
| 7.5 mg | 4 weeks | £300 |
| 10 mg | 4 weeks | £350 |
| 12.5 mg | 4 weeks | £375 |
| 15 mg | 4 weeks | £399 |
All prices include your private prescription, clinical review, and next-day cold-chain delivery.
Order safely at
➡️ PPRX Mounjaro KwikPen UK
or complete your consultation here:
➡️ Weight-Loss Consultation Form.
FAQs
Do Mounjaro side effects go away?
Yes. Most mild effects like nausea or bloating improve within the first month.
Can I take painkillers or antacids with Mounjaro?
Usually yes, but always confirm with your pharmacist to avoid interactions.
Will increasing the dose worsen side effects?
Temporarily, possibly. Follow your prescriber’s gradual titration plan to minimise this.
Pharmacist Review
Written and reviewed by a GPhC-registered pharmacist, following MHRA and NICE guidance on tirzepatide for safe use in the UK.
Start your order today at www.pprx.co.uk
At PPRX UK, we provide:
- Genuine Mounjaro pens, sourced directly from the manufacturer (Eli Lilly)
- Dispensing via a GPhC-registered UK pharmacy
- Professional consultations with UK pharmacists
- Ongoing support, dosage guidance, and repeat supply options
Whether you’re just starting or switching from Ozempic or Wegovy, we’re here to help.
📞 Get in Touch
Visit www.pprx.co.uk or contact us directly to begin your online consultation.
We offer fast, discreet UK-wide delivery and exceptional support throughout your journey.
Mounjaro is a prescription-only medicine. This article is for informational purposes only and does not replace medical advice. Always consult a qualified healthcare provider before starting treatment. nhs
