Donald Trump’s tariff war may threaten the supply of blockbuster weight loss jabs relied on by millions of British slimmers, experts have warned. 

The President this week announced he would soon impose ‘major’ tariffs on the pharmaceutical industry to shift the overseas production of medications back to the United States. 

It was a ‘tremendous problem’ that the country ‘can no longer produce enough antibiotics to treat our sick,’ he claimed. 

But now, British industry leaders fear such tariffs could disrupt the supply and even the price of drugs including slimming jabs Mounjaro and Ozempic — both hailed as a monumental breakthrough in the war on obesity.

Experts today said patients may ‘end up the casualties of a global trade war’ and urged the UK Government to ‘closely monitor’ the evolving situation. 

Chief executive of the Company Chemists’ Association — which represents large high street chemists such as Boots and Superdrug — Malcolm Harrison told MailOnline that new trade tariffs could certainly impact the supply of the jabs.

He added: ‘Global medicines supply chains are complex and often involve the movement of raw ingredients, excipients, packaging materials, and finished products across several international borders.

‘We urge the government to closely monitor the situation.’

President Trump this week announced he would ‘very shortly’ impose ‘major’ tariffs on the pharmaceutical industry to shift the overseas production of medications back to the United States

British industry leaders fear such tariffs could disrupt the supply and even the price of drugs including slimming jabs Mounjaro and Ozempic — both hailed as a monumental breakthrough in the war on obesity 

Professor Martin McKee, a public health expert at the London School of Hygiene and Tropical Medicine, also told The i that tariffs on pharmaceuticals could spark ‘chaos’.

He added: ‘We don’t know how particular drugs like weight-loss drugs will be impacted. But we can’t rule out they will be disrupted, along with everything else.’ 

The pharmaceutical supply chain is already ‘complex’, he also told MailOnline. 

‘This is why trade negotiations take so long and why decisions on tariffs, should not be conjured up by those who do not understand them,’ he added. 

‘No doubt the manufacturers of any medicine sold in the United States will be scrambling to understand the consequences of President Trump’s constantly changing orders but anyone who thinks they know what will happen is probably deluding themselves. 

‘The once thing that is certain is that this is not a good time to be making major investments in the United States.’

Professor Claire Anderson, president of the Royal Pharmaceutical Society (RPS), meanwhile warned that patients could ‘end up the casualties in a global trade war’.

‘Supply chain vulnerabilities make it harder for patients to access treatment, causing frustration, anxiety and in some cases, harm to patient health,’ she added. 

Eli Lilly produces Tirzepatide — the active ingredient in popular weight-loss drug Mounjaro — in Ireland, making it the country’s largest pharmaceutical export to the US

In his announcement, President Trump declared US-based multinational drug companies with operations overseas would come ‘rushing back into our country’ to avoid the extra costs of doing business outside America.

But in the wake of his comments, American drug maker giants including Mounjaro manufacturer Eli Lilly, saw their share prices fall. 

Eli Lilly produces Tirzepatide — the active ingredient in popular weight-loss drug Mounjaro — in Ireland, making it the country’s largest pharmaceutical export to the US. 

David Ricks, the head of Eli Lilly, told the BBC last week that he did not support Trump’s tariffs but suggested the firm may be forced to reassess its European supply chain.

Eli Lilly would have to ‘look at the flow of goods because we wouldn’t want to have to pay tariffs if we didn’t need to’, he said. 

European pharma lobbying group EFPIA — whose members include Ozempic and Wegovy manufacturer Novo Nordisk — also said on Tuesday that it had ‘strong concerns’ about the impact of tariffs.   

Other experts today, however, suggested that manufacturers themselves could absorb any extra costs from the tariffs given weight loss jabs have been lucrative. 

Dr Andrew Hill, a senior visiting research fellow in pharmacology and therapeutics at the University of Liverpool, told MailOnline: ‘The estimated cost of production for semaglutide — Wegovy or Ozempic — is approximately £4 per month.

President Donald Trump unveils reciprocal tariffs he planned to place on countries all over the world during his April 2 ‘Liberation Day’ event in the White House Rose Garden 

‘Yet, injections of semaglutide in the UK are often sold at between £150 to £200 per month.

‘Novo Nordisk are making huge profits, and so should be able to absorb costs of tarriffs. Their profits in 2024 were over $18 billion.

‘As a European company, the costs should not be affected when exporting from Europe to the UK.’

MailOnline has approached Eli Lilly for comment. Novo Nordisk declined to comment when approached. 

At least half a million NHS patients and some 15million in the US are now thought to be using weight loss jabs, which can help patients lose up to 20 per cent of their bodyweight in just a few months.

They have also been shown to significantly reduce the risk of heart attacks and strokes.

However, other reported problems using the jabs include constipation, fatigue, headaches, dizziness and even hair loss. 

Under official guidelines, only patients who have a body mass index (BMI) of over 35 and at least one weight-related health problem like high blood pressure, or those who have a BMI of 30 to 34.9 and meet the criteria for referral to a specialist weight management service, should be prescribed weight loss jabs.

In the UK, law forbids the sale of such drugs without a prescription from a medical professional. 

Last year, the RPS also warned that scam online retailers posing as pharmacies were targeting vulnerable patients and may even be selling contaminated versions of the blockbuster injections.