Eli Lilly & Co. will raise the list price of its weekly weight-loss and diabetes injection Mounjaro in the United Kingdom by as much as 170 % from 1 September. The cost of a month’s supply of the highest 15-mg dose will jump to £330 ($420) from £122, while the lowest 2.5-mg pen will climb to £133 from £92. The increase affects privately paid prescriptions; the price agreed with the National Health Service remains unchanged. The Indianapolis-based drugmaker said the move aligns UK prices with those in other European markets and supports President Donald Trump’s “most favoured nation” initiative, which calls on pharmaceutical companies to lift prices overseas and cut them in the United States. Lilly added that it is discussing similar adjustments with other European governments ahead of the 1 September deadline. Mounjaro, also known as tirzepatide, entered the UK market in February 2024 and is prescribed for obesity and type 2 diabetes. Retailers estimate that about 500,000 people in Britain buy either Mounjaro or Novo Nordisk’s rival Wegovy privately, underscoring surging demand for GLP-1 weight-loss therapies. Separately this week, Lilly introduced the six-dose Mounjaro Kwikpen in India, pricing the entry 2.5-mg monthly pack at 14,000 rupees (about $160). The Indian launch widens Lilly’s global reach and intensifies competition with Novo Nordisk, which released Wegovy pens in the country in June.