Weight loss medicines in England

This briefing focuses on the availability of new weight loss medications on the NHS in England. It does not discuss the clinical effectiveness of these medicines.

The commissioning and delivery of public health services is devolved; this briefing focuses on arrangements in England.

A Commons Library briefing, Obesity policy in England, provides information on the government’s wider work on obesity.

NHS weight management services in England

In England, weight management services are commissioned in a dual manner. NHS England commissions some services, which are available to all patients in England. Local services are commissioned by local authorities and integrated care boards (ICBs).

Weight management services can be categorised in tiers. Tier 1 and 2 services focus on providing information and guidance on nutrition, physical activity and lifestyle in a generic and high-level way. They are the most accessible services to patients.

Tier 3 services are specialist services aimed at providing targeted, personalised interventions to people with severe obesity and related health problems (comorbidities). They require referral and have tighter eligibility criteria, making them less accessible to patients. Tier 4 services include providing access to bariatric (weight loss) surgery.

Generally, in the NHS, weight loss medicines are only available in tier 3 and 4 services.

GLP-1 medicines

GLP-1 medicines are weight-loss medicines that mimic the actions of glucagon-like peptide-1 (GLP-1).

GLP-1 has several effects on the body, including reducing appetite and helping the body to produce more insulin (the hormone that regulates blood sugar).

GLP-1 medicines are useful in the treatment of type 2 diabetes, and for weight loss and weight management.

Semaglutide (Ozempic and Wegovy)

Semaglutide is a medicine within the GLP-1 class. In the UK, it is available as three branded products:

• Ozempic, for type 2 diabetes,
• Wegovy, for weight management, and
• Rybelsus, for type 2 diabetes

In England, the National Institute for Health and Care Excellence (NICE) has recommended semaglutide as a weight loss treatment for patients in specialist weight management services. The eligibility criteria for receiving semaglutide include having a BMI of at least 30 kg/m2 and having at least one weight-related comorbidity.

Lower BMI thresholds apply to people from minority ethnic backgrounds to reflect the greater risk of obesity-related illness they experience, compared to people from White ethnic groups.

Tirzepatide (Mounjaro)

Tirzepatide is another medicine within the GLP-1 class. It is available as a branded product called Mounjaro.

The Medicines and Healthcare products Regulatory Agency (MHRA) licensed tirzepatide for weight loss and weight management in adults aged 18 years and over in November 2023. Tirzepatide had already been licensed for the treatment of type 2 diabetes in adults in October 2022.

NICE’s final guidance on the use of tirzepatide in the NHS recommended that it should be made available on the NHS, to adults with a BMI of at least 35 kg/m2, and with at least one weight-related comorbidity. Lower BMI thresholds would be applied to people from minority ethnic backgrounds.

NICE guidance on the use of tirzepatide (Mounjaro) in the NHS

NICE is responsible for evaluating medicines based on their clinical effectiveness and cost-effectiveness. If NICE makes a positive recommendation for a medicine, the default requirement is for NHS service providers to ensure that patients can access the medicine within three months of the recommendation.

Draft guidance (June 2024)

In June 2024, NICE published its draft guidance on tirzepatide for the management of overweight and obesity (PDF) in June 2024.

It recommended that NHS service providers make tirzepatide available for managing overweight and obesity alongside a reduced-calorie diet and increased physical activity. It recommended this for adults with a BMI of at least 35 kg/m2, and with at least one weight-related comorbidity.

NICE invited stakeholders to comment on the draft guidance.

NHS England’s request to extend the rollout period for tirzepatide

Following publication of the draft guidance, NHS England requested an extension for the rollout period for tirzepatide (PDF) (known as a funding variation).

The request, which was made on behalf of NHS Providers and ICBs, called for tirzepatide to be introduced in phases. This would offer access to patients in order of priority, over a maximum 12-year period and allow time for service providers to put staffing, training and resource capacity in place.

NHS England said a phased implementation would ensure that wraparound weight management services, needed by people taking tirzepatide, could be adequately provided. NHS England raised concern that there were not enough weight management services in primary care, which put pressure on existing community and non-specialist services. NHS England cautioned that a three-month rollout would have a “highly damaging impact on wider population access to GP services”.

NHS England estimated that 2.8 million patients would become eligible to use tirzepatide (PDF) within 90 days of the final draft guidance being published. If all of these people presented for treatment in the first year it became available, NHS England estimated (PDF) that the cost of providing the medicine and wraparound services would amount to £15.2 billion over five years.

Finalised guidance (December 2024)

NICE published its finalised guidance on tirzepatide for managing overweight and obesity (PDF) in December 2024. Its recommendation on BMI thresholds and clinical eligibility remained the same as those proposed in its June 2024 draft guidance.

NICE estimated that 3.4 million people would be eligible for treatment.

Phased implementation period

NICE acknowledged some of the concerns voiced by NHS England and suggested a phased rollout for tirzepatide in response. Under the finalised guidance, NHS service providers will be required to make tirzepatide available as follows:

• Within 90 days of the guidance’s publication, for patients already receiving treatment in specialist weight management services.
• Within 180 days of the guidance’s publication, for a further cohort of high-priority patients (with eligibility to be determined by NHS England)
• Within three years of the guidance’s publication, for an expanded group of patients (with eligibility to be determined by NHS England). NICE expects that, at the end of this three-year period, around 220,000 patients would have become eligible for treatment.
• Within 12 years of the guidance’s publication, for the remainder of eligible patients.

NICE plans to conduct a review after three years of the final guidance’s publication. The review will consider the implementation of the rollout up until that point. As part of the review, NICE will assess whether changes to its recommendations in the final guidance are needed.

Response to the rollout of tirzepatide (Mounjaro) on the NHS

Prime Minister Keir Starmer has said that new weight loss medicines “could be very important for our economy and for health”. He and the Health Secretary Wes Streeting have suggested they could play a role in supporting people to re-join the workforce.

Professor Sir Stephen Powis, national medical director at NHS England, said tirzepatide would be a “powerful part of our arsenal” against obesity. Sir Stephen said a phased rolled out would ensure those with greatest clinical need would be able to access tirzepatide as a priority, while NHS England further develops its weight loss services.

With reference to NHS England’s proposed implementation plan, the Obesity Health Alliance (OHA, PDF) said addressing longstanding issues and establishing a system for prioritising patients was an “immediate and unavoidable priority”. The OHA highlighted barriers to providing new weight loss medicines in the NHS and cautioned that provision through the private sector rather than the NHS risks increasing health inequalities.

NHS chief executive Amanda Pritchard described cost-effective weight loss medicines as a “game-changer”, but cautioned that “without transforming pathways they could overwhelm already-stretched services”.

Investment and clinical trials into weight loss medicines

In October 2024, the government announced details of a £279 million investment, supported by Eli Lilly (which manufactures Mounjaro), to support the UK life sciences sector.

Part of the £279 million will be used to fund a five-year clinical trial, based in Manchester, evaluating the effectiveness of tirzepatide in weight loss, preventing diabetes, and preventing obesity-related complications for adults with obesity.

The SURMOUNT-REAL UK trial will be run by Health Innovation Manchester, in collaboration with the University of Manchester, and NorthWest Ehealth.

Footnotes