Obesity Drugs on the NHS: Who Qualifies, What They Do, and What Comes Next

The emergence of GLP-1 receptor agonists — drugs like semaglutide (marketed as Wegovy for weight management and Ozempic for diabetes) and tirzepatide (Mounjaro) — represents the most significant advance in obesity treatment in a generation.

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What These Drugs Do

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GLP-1 drugs work by mimicking a hormone that regulates appetite, slowing gastric emptying and reducing hunger signals. In clinical trials, semaglutide achieved average weight loss of 15–17% of body weight — roughly double what was achievable with previous medications. Tirzepatide achieved 20–22% in pivotal trials.

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Who the NHS Will Treat

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NHS England has approved semaglutide for use in specialist weight management services. The criteria are stringent: a BMI of 35 or above with at least one weight-related comorbidity (diabetes, high blood pressure, sleep apnoea), or a BMI above 40 regardless of other conditions.

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This represents approximately 3.4 million people in England — but NHS capacity to prescribe, monitor, and supply the drugs is a significant constraint. The roll-out through specialist services will take years to scale.

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The Cost Question

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Wegovy costs approximately £270 per month at list price. For the NHS, which negotiates lower rates, the cost is confidential but significant. The health economic case for treatment — reduced cardiovascular events, diabetes remission, reduced joint replacement — appears compelling, but budget pressure limits deployment.

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What Patients Should Know

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These drugs are not available as standalone treatments from a GP. They require specialist referral and ongoing monitoring. Private prescribing is available but expensive and carries risks if not properly supervised.

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