The price of ‘King Kong’ fat jab Mounjaro will almost triple from September adding a potential £2,704 a year to the cost of the drug.

Manufacturer Lilly has announced plans to hike the amount it charges private providers in the UK to bring it into line with ‘other developed countries’.

It also cited clinical research into the effectiveness of the injections, saying it demonstrates its ‘value’.

The hike comes after US President Donald Trump complained that Americans pay more for drugs than other nations, saying they ‘subsidise the health care of foreign countries’.

The list price of a 15mg KwikPen, which is the highest dose available and enough for four weekly shots, will increase from £122 to £330.

Meanwhile, the cost of a 2.5mg pen, the lowest dose available, will rise from £92 to £133 from September 1, the firm said.

It means the annual cost of the 15mg dose will increase from £1,586 a year to £4,290. The price the NHS pays will not change.

Lilly is negotiating prices individually with private providers, who may be able to secure a discount they can pass on to customers.

A 5mg Mounjaro KwikPen—soon the cost will TRIPLE

A 5mg Mounjaro KwikPen—soon the cost will TRIPLE

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But the company said it is down to pharmacies to set the price they charge and this may include processing fees and consultation fees.

Dr Leyla Hannbeck, chief executive of the Independent Pharmacies Association, which represents thousands of community pharmacies, said: ‘We are shocked and very disappointed by this huge more than doubling of the wholesale cost of Mounjaro by the manufacturer Eli Lilly.

‘British patients must not become pawns in a wider dispute about the costs of medicines arising from President Trump’s recent letter to the US drug manufacturers.’

Studies have shown patients taking tirzepatide, the active drug in Mounjaro, lost 20 per cent of their body weight over 72 weeks.

It works by targeting the GLP-1 receptors, which suppress appetite and make users fill fuller for longer.

Mounjaro price increases Mounjaro®▼ (tirzepatide) KwikPen® Dose Current UK List PriceNew UK List Price (From September)  2.5mg £92£133  5mg £92£180 7.5mg £107 £255 10mg £107 £255 12.5mg £122 £330 15mg £122 £330 

GLP-1 injections suffered global shortages after celebrity users sparked a surge in popularity and the NHS has warned people against buying them from unauthorised sources.

A Lilly spokesperson said: ‘Following a review, Lilly will increase the UK list price for Mounjaro (tirzepatide) from 1 September to address pricing inconsistencies compared to other developed countries, including in Europe.

‘In parallel, we have reached an agreement with the NHS to ensure continued supply and patient access.

‘While Lilly does not determine the prices that private healthcare providers set, we are working with them to maintain patient access.

‘The UK was one of the first countries where Lilly launched Mounjaro, and our priority was to bring it to patients as quickly as possible during a time of limited supply of GLP-1 RA treatments for type 2 diabetes.

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‘At launch, Lilly agreed to a UK list price that is significantly below the European average to prevent delays in NHS availability.

‘With changes in the environment and new clinical evidence supporting the value of Mounjaro, we are now aligning the list price more consistently to ensure fair global contributions to the cost of innovation.’

Two in three adults in Britain are obese or overweight and more than 5million people have type-2 diabetes, which is linked to poor lifestyles.

Estimates suggest one in ten women already take weight loss jabs. 

An NHS England spokesperson said: ‘Licensed, cost-effective weight loss medication, such as tirzepatide (Mounjaro) provides a valuable tool to support people to reach a healthier weight and the wider health and lifestyle benefits that offers.

‘The approved list price increase will not affect NHS commissioning of tirzepatide in England for eligible people living with obesity, based on clinical priority, or as a treatment for type 2 diabetes.

‘Anyone with questions about their private tirzepatide prescription should contact their private provider.’