The use of weight-loss drugs such as GLP-1 receptor agonists (e.g., semaglutide, tirzepatide) has increased rapidly in recent years. These drugs can help some people achieve significant weight reduction, but they are not suitable for everyone and require careful counselling before starting treatment. By discussing benefits, risks, practicalities, and uncertainties, clinicians can help patients make informed, realistic decisions about their treatment.
Key points to discuss with patients
1. Indications and eligibility
These drugs are usually licensed for adults with a specific BMI. They should be used alongside lifestyle interventions such as dietary change, increased physical activity, and behaviour modification.
2. Potential side effects – some can be serious
Common adverse effects include nausea, vomiting, diarrhoea, and abdominal discomfort. Less common but more serious risks include gallstones, pancreatitis and visual problems. Patients should know what to watch for and when to seek urgent medical advice.
3. Loss of muscle mass as well as fat
Treatment often leads to loss of both fat and lean tissue (muscle). Reduced muscle mass can affect strength, mobility, and metabolic rate. Encourage resistance exercise and adequate protein intake to help maintain muscle.
4. Long-term safety and unknowns
While clinical trials show substantial short- to medium-term benefits, we do not yet have decades of safety data for newer agents. Patients should be aware that some long-term effects remain unknown.
5. Need for sustained treatment
For many, continued use is required to maintain weight loss. This raises issues around cost, availability, and the practicality of long-term therapy.
6. Likelihood of weight regain after stopping treatment
Most people regain much of the weight lost when medication is discontinued unless lifestyle measures are sustained.
7. Impact on mental health and eating behaviour
Changes in appetite can be beneficial but, rarely, may lead to problematic eating patterns. Monitoring for disordered eating is important.
8. Contraindications and drug interactions
Caution is needed in people with a history of pancreatitis, certain gastrointestinal diseases, or relevant endocrine tumours. Review other medications for potential interactions.
9. Monitoring requirements
Ongoing follow-up is essential to assess weight, metabolic health, nutritional status, muscle mass, and side effects.