Eli Lilly, the manufacturer of the popular weight-loss drug Mounjaro (tirzepatide), has announced significant price increases and a temporary supply freeze in the UK, effective from September 1. This decision has sparked widespread panic among patients and raised concerns about affordability and access to a medication lauded for its efficacy in combating obesity.

Initially, Lilly indicated that the wholesale price of Mounjaro would soar, with the highest 15mg dose rising from £122 to £330 per month, and a 5mg pen jumping from approximately £92 to £180. However, subsequent commercial arrangements struck between Lilly and private providers, revealed in documents, indicate that the price hike will not be as steep as initially feared. Under these new deals, the top 15mg dose will increase to £247.50, almost £100 less than the previously announced list price, while the 5mg dose will rise to £135. Lilly justified the price adjustment by stating that Mounjaro was initially launched in the UK at a price "significantly below the European average to prevent delays in NHS availability," and that this change is necessary "to ensure fair global contributions to the cost of innovation."

The announcement triggered a surge in demand and "Covid-style" panic buying, leading many patients to attempt to stockpile months' worth of the drug. In response to this "unprecedented demand" and to prevent pharmacies from stockpiling at lower prices, Lilly requested a temporary UK-wide freeze on orders. Medicines distributor Phoenix informed pharmacies that orders received after August 27 would not be processed, with normal ordering set to recommence on September 1. Health leaders, including Dr Leyla Hannbeck, CEO of the Independent Pharmacies Association, criticized Lilly's move as "unacceptable," causing "significant instability" and "throwing the system into chaos," arguing that patients are suffering due to the company's "pursuit of profit."

Experts fear that the increased prices could push more people towards the black market, where unregulated distributors might offer fake, contaminated, or incorrectly dosed jabs, posing serious health risks. Border Force seizures at Heathrow between June 2024 and June 2025 confiscated over 18,000 illegal weight-loss and diabetes medications, including counterfeit Mounjaro pens, highlighting this growing danger.

The situation has created a profound dilemma for patients like Julia Dore, 51, and Jenny Lloyd, 50, who self-funded Mounjaro treatment, experienced life-changing weight loss, but now find themselves ineligible for NHS prescriptions. Julia Dore, who lost five-and-a-half stone, and Jenny Lloyd, who lost almost 5 stone and saw her diabetes go into remission, both started Mounjaro privately when it wasn't available on the NHS. Due to their significant weight loss, their Body Mass Index (BMI) dropped below the strict NHS eligibility criteria (BMI over 35, or BMI over 40 with multiple comorbidities), leaving them in a position where doctors suggested they would need to regain weight to qualify. This prospect has been described as "soul-destroying" and "a big risk" by the affected patients, who feel abandoned by the system.

Mounjaro has demonstrated superior weight loss in clinical trials, with patients losing an average of up to 22.5 percent of their body weight over 72 weeks at the highest dose, compared to Wegovy (semaglutide) patients losing up to 17.5 percent. For those unable to afford the rising private costs, switching to alternatives like Wegovy is an option, but requires consultation with a healthcare provider due to differing strengths and the need for a 'wash-out' period. A month's supply of the largest Wegovy dose (2.4mg) is available for around £200 from online pharmacies.

Current official guidelines mandate weight-loss jabs for patients with a BMI over 35 and at least one weight-related health problem, or those with a BMI of 30-34.9 meeting specialist referral criteria. The NHS, in a phased rollout, initially offered Mounjaro only to the sickest patients (BMI over 40 with four comorbidities). While criteria are set to relax from next year (BMI over 35 with four comorbidities) and further in September 2026 (BMI over 40 with three conditions), the NHS warns it could take up to 12 years to treat all four million eligible individuals. This extended timeline, coupled with the rising cost of private treatment, exacerbates the challenges for patients.

The broader context is the UK's obesity crisis, with nearly two-thirds of adults in England overweight and an estimated 14 million people obese. This crisis costs the NHS over £11 billion annually and billions more in lost productivity. Hope for future affordability and access lies in the development of new GLP-1 drugs, such as retatrutide (potentially 30% weight loss) and orforglipron (an oral pill), and increased market competition, though these are still some years away. Until then, healthcare providers suggest lifestyle changes for those stopping the injections, focusing on diet and physical activity to maintain weight loss.