Key questions on obesity medications

GP and expert in obesity and lifestyle medicine Dr Ellen Fallows answers key questions on the prescribing of medications for weight loss in patients with obesity.

The management of obesity has been transformed in recent years with the use of glucagon-like peptide-1 receptor agonist (GLP-1 RA) drugs semaglutide (Wegovy) and liraglutide (Saxenda), and the dual GLP-1/glucose-dependent insulinotropic polypeptide (GIP) RA tirzepatide (Mounjaro).

The prescribing of tirzepatide in NHS primary care, albeit as part of a phased roll-out, and wider prescribing of all these drugs through private providers, has shifted much more responsibility for the medical management of obesity onto GPs.

Experience and real-world evidence with these drugs are constantly evolving, including on side effects and potential interactions, while eligibility and availability varies over time and by region, presenting a challenge for GPs to keep on top of the constantly shifting focus.

Learning objectives

This module will bring you up to date and extend your knowledge of:

• Efficacy, safety profile and clinical role of oral and injectable pharmacological treatments for obesity, including orlistat and injectable GLP-1-based therapies.
• Current UK eligibility criteria for semaglutide, liraglutide and tirzepatide across England, Wales and Scotland, recognising regional variation and phased commissioning arrangements.
• Interpret forthcoming changes to tirzepatide eligibility in England, including BMI thresholds, qualifying comorbidities and the interaction between obesity and type 2 diabetes guidance.
• Identify, counsel and manage common adverse effects of GLP-1-based agents, including perioperative considerations and medication adjustments in patients with type 2 diabetes.
• Support shared decision-making regarding treatment targets, duration of therapy, discontinuation and risk of weight regain, including considerations for repeat prescribing and private-sector treatment.

Author: Dr Ellen Fallows is a GP with specialism in obesity, a fellow of the British Society of Lifestyle Medicine and past RCGP advisor on obesity and type 2 diabetes

Date published: 13.02.2026