Weight Loss Drugs Explained: Ozempic, Wegovy & Mounjaro | NHS & Medical Guide

A Medical Student’s Guide to Weight Loss Drugs: Ozempic, Wegovy & Mounjaro 🎓💊

⚠️ Disclaimer: This guide is intended for educational purposes only and is not a substitute for professional medical advice. Patients should always consult their doctor before starting, stopping, or changing any medication.

Introduction

With the increasing prevalence of obesity, weight loss medications such as Ozempic, Wegovy, and Mounjaro have gained attention in both medical practice and public discourse. Understanding these drugs is crucial for medical students preparing for interviews, as well as for future clinical practice.

This guide will cover: ✅ Indications ✅ Mechanisms of action ✅ Common side effects ✅ NHS policies ✅ Evidence supporting their use ✅ Patient safety considerations

1. What Are These Drugs?

• Ozempic (Semaglutide): GLP-1 receptor agonist, primarily used for Type 2 diabetes but also prescribed off-label for weight loss.

• Wegovy (Semaglutide): GLP-1 receptor agonist, specifically designed for weight management.

• Mounjaro (Tirzepatide): Dual GIP & GLP-1 receptor agonist, used for Type 2 diabetes and weight loss.

💡 Definitions:

• GLP-1 receptor agonist: A drug that mimics the hormone GLP-1, which helps regulate blood sugar and appetite.

• GIP receptor agonist: A drug that affects glucose metabolism and weight regulation.

2. How Do These Drugs Work? 🧬

These medications primarily act by mimicking incretin hormones that regulate glucose and appetite:

• Ozempic & Wegovy (Semaglutide) activate GLP-1 receptors, leading to:

  • Increased insulin secretion 📈

  • Reduced glucagon secretion 📉

  • Delayed gastric emptying (making patients feel full longer) 🍽️

  • Appetite suppression 🛑

• Mounjaro (Tirzepatide) has a dual mechanism:

  • Activates both GLP-1 and GIP receptors, which leads to enhanced metabolic and appetite control.

How Effective Are They?

Clinical Evidence:

• Semaglutide (Wegovy): A study in the New England Journal of Medicine (2021) found that patients lost an average of 15% of their body weight over 68 weeks.

• Tirzepatide (Mounjaro): Trials demonstrated up to 20% weight loss, making it one of the most effective anti-obesity medications currently available.

3. Who Can Use These Medications? (Indications) 🤔

NICE Guidelines & NHS Policy

• Ozempic (Semaglutide) is only licensed for Type 2 diabetes in the UK. However, some doctors prescribe it off-label for weight loss.

• Wegovy (Semaglutide) was approved by NICE (2023) for weight management in patients with:

  • BMI ≥ 30 kg/m² (Obesity)

  • BMI ≥ 27 kg/m² with weight-related health conditions (e.g., hypertension, Type 2 diabetes)

  • Available via specialist NHS weight management services

• Mounjaro (Tirzepatide) is currently only approved for Type 2 diabetes but is expected to be licensed for obesity soon.

4. Common Side Effects ⚠️

• Nausea 🤢 – Very common

• Vomiting 🤮 – Common

• Diarrhoea 💩 – Common

• Constipation – Common

• Pancreatitis (rare) 🔥 – Rare but serious

• Thyroid Tumours (potential risk) – Observed in animal studies

💡 Key Takeaway: Most side effects are gastrointestinal and tend to improve over time.

5. Patient Safety & Contraindications ⚕️

Who Should NOT Take These Drugs?

• Patients with personal or family history of medullary thyroid cancer

• Those with multiple endocrine neoplasia syndrome type 2 (MEN2)

• Individuals with severe gastrointestinal disorders (e.g., gastroparesis)

• Pregnant or breastfeeding women

Important Safety Considerations

✅ Monitor blood sugar levels in diabetic patients to avoid hypoglycaemia (especially when combined with insulin or sulfonylureas). ✅ Gradual dose escalation helps reduce nausea and vomiting. ✅ Encourage lifestyle changes alongside medication use for best results.

6. NHS Availability & Cost 💷

• Ozempic: Available on the NHS for Type 2 diabetes, but not for weight loss.

• Wegovy: Recently approved for obesity treatment on the NHS, but only in specialist services.

• Mounjaro: Currently under review for NHS obesity treatment.

Private Prescriptions

• Due to high demand, many patients seek private prescriptions at significant cost (e.g., £150-£250 per monthfor Wegovy).

• There have been shortages of Ozempic due to off-label prescribing for weight loss.

7. Ethical Considerations & Medical Interviews 🎤

Potential Questions in a Medical School Interview

❓ What are the benefits and risks of using GLP-1 agonists for weight loss? ❓ How would you counsel a patient requesting Ozempic for weight loss? ❓ What are the ethical concerns of prescribing weight loss drugs to non-diabetic patients?

Ethical Dilemmas 🏥

• Equity of access: Should NHS resources be allocated to weight loss drugs when demand exceeds supply?

• Medicalisation of obesity: Should weight loss be primarily treated with lifestyle changes before medication?

• Pharmaceutical influence: Are financial incentives affecting prescribing patterns?

8. Final Thoughts & Key Takeaways 📝

🔹 GLP-1 and GIP/GLP-1 receptor agonists are revolutionising obesity treatment. 🔹 NHS only funds Wegovy for obesity, while Ozempic is approved for diabetes only. 🔹 Gastrointestinal side effects are common but generally tolerable. 🔹 Patient safety is crucial—not suitable for everyone. 🔹 Medical ethics play a role in prescribing these drugs.

By understanding these concepts, you’ll be well-prepared to discuss weight loss drugs in medical school interviews and future clinical practice! 🎓🩺

References:

1. Wilding, J. P. et al. (2021). N Engl J Med.

2. NICE Guidelines (2023). Management of Obesity.

3. Jastreboff, A. M. et al. (2022). Obesity Trials.