A new study by researchers at University College London has revealed that an estimated 1.6 million adults in England, Wales and Scotland used weight loss drugs such as Mounjaro between 2024 and 2025. While these medications can be effective for weight management, some mortgage brokers are warning that the monthly costs associated with them could affect the size of mortgage that borrowers can obtain.
When applying for a mortgage, lenders conduct detailed affordability checks on applicants’ income and outgoings. Regular payments for privately prescribed weight loss injections, which can range from £200 to £300 per month, could be treated similarly to other committed expenses. This could potentially reduce the maximum loan offered to first-time buyers by up to £20,000, according to Jamie Alexander, mortgage director at the broker Alexander Southwell Mortgages.
However, opinions within the mortgage industry are divided on the potential impact. Some experts argue that these expenses may be viewed as “discretionary” spending that could be cancelled, and therefore may not significantly affect affordability assessments. Others, like Aaron Strutt at the broker Trinity Financial, suggest that lenders would likely want to know about such substantial monthly outgoings.
David Hollingworth of the broker L&C Mortgages said he had not heard of this issue “causing major problems” and that it was largely likely to be seen as discretionary spending. But he acknowledged the possibility that an underwriter might raise questions about it.
Nicholas Mendes at the broker John Charcol noted that if a lender were to scrutinise someone’s bank statements, any outgoings that could be viewed as quite high would likely prompt questions. However, he added that this was “something that someone could cancel.”
The growing popularity of weight loss drugs has implications for homebuyers, particularly first-time buyers or those on tighter budgets. Mortgage brokers advise that would-be borrowers should be mindful of their spending on such treatments in the months leading up to a mortgage application, as lenders may factor these costs into their affordability assessments.
