England's ICBs must start funding tirzepatide in specialist weight management services

Ninety days after the National Institute for Health and Care Excellence (NICE) published its final guidance on tirzepatide, England's Integrated Care Boards (ICBs) became legally required, as of March 24, 2025, to fund the drug for obesity treatment in NHS specialist weight management services ^[1]. Tirzepatide is sold under the brand name Mounjaro for weight management in the United Kingdom ^[1].

Under the NICE technology appraisal known as TA1026, tirzepatide is recommended alongside a reduced-calorie diet and increased physical activity for adults who have a body mass index (BMI) of at least 35 kg/m², plus at least one weight-related health condition ^[1]. For people from South Asian, Chinese, other Asian, Middle Eastern, Black African, or African-Caribbean backgrounds, the BMI threshold is typically lowered by 2.5 kg/m² ^[1]. NHS England estimates that about 3.4 million people in England meet these criteria ^[1].

Because the NHS could not immediately treat everyone who qualifies, NHS England asked NICE for more time. NICE's Guidance Executive agreed and set a phased schedule: from March 24, 2025, ICBs must fund tirzepatide in specialist weight management services for anyone meeting the eligibility criteria and whose treatment is approved by a prescribing clinician ^[1]. Access through primary care, such as general practice, follows a separate and slower timeline, starting June 23, 2025, for prioritized patient groups, reflecting limited capacity in that setting ^[1].

The funding variation sets a target of expanding primary care access to roughly 220,000 people over the first three years of rollout, from 2025 to 2028 ^[1]. The full eligible population of 3.4 million is expected to gain access over a maximum period of up to 12 years, with priority determined by clinical need ^[1]. NHS England says it developed this "cohorting approach" by working with clinical experts, ICBs, patients, charities, and Royal Colleges ^[1].

Why it matters for patients

For patients in England, this means the type of clinic they use affects how soon they might get tirzepatide covered by the NHS. Anyone who meets NICE's BMI and comorbidity criteria and is referred to a specialist weight management service should, as of March 24, 2025, have access to funded treatment if their clinician approves it ^[1]. Patients hoping to get tirzepatide through their regular doctor's office, however, face a longer wait and will be brought in in phases based on prioritization criteria that NHS England has not fully detailed in this document ^[1].

The scale of the rollout also matters. NHS England notes that obesity costs the NHS about £11.4 billion a year, with a wider societal cost of £74.3 billion annually, which is part of the rationale for expanding drug access despite capacity constraints ^[1]. Even so, the source makes clear the full eligible population will not all get access at once, and some patients may wait years depending on where they fall in the prioritization plan ^[1]. Tirzepatide also carries a