Regularly spending hundreds of pounds on private prescriptions for weight loss drugs could significantly reduce the amount homebuyers are able to borrow for a mortgage, financial experts have warned.
How Monthly Outgoings Affect Borrowing Power
When applying for a mortgage, lenders conduct rigorous affordability checks, scrutinising an applicant's income against all regular outgoings. These include not only credit commitments but also subscriptions, memberships, and other recurring payments.
According to Jamie Alexander, mortgage director at Alexander Southwell Mortgages, monthly payments of £200 to £300 for privately prescribed weight loss injections could be treated as a committed bill. For a typical first-time buyer, this could reduce the maximum loan offered by up to £20,000.
"Lenders will treat them like any other committed bill – even if they never ask you about it," Alexander stated. "A regular £200 to £300 outgoing could reduce your spare income in affordability checks, so the maximum loan on offer shrinks."
A Nationwide Trend in Private Prescriptions
The warning comes amid a dramatic surge in the use of weight loss medications across Great Britain. A study published this month by researchers at University College London (UCL) estimated that 1.6 million adults in England, Wales, and Scotland used drugs such as Wegovy and Mounjaro to aid weight loss between early 2024 and early 2025.
The vast majority access these treatments privately, with monthly costs last year typically ranging from £100 to £350 at supermarkets and pharmacies. Prices have since risen for some drugs, leading some users to seek cheaper alternatives.
Diverging Views from Mortgage Experts
There is, however, no consensus within the mortgage industry on how these payments are assessed. Some brokers argue the spending is often viewed as "discretionary" – something a borrower could choose to stop – and therefore may not impact the loan amount.
David Hollingworth of broker L&C Mortgages said he had not seen the issue cause major problems, noting it was "largely likely to be seen as discretionary spending." He added, "It's not something that's likely to be picked up en masse."
Conversely, Aaron Strutt at Trinity Financial warned that if a lender spots several hundred pounds in monthly payments on bank statements, "they are probably going to want to know about it." While not a formal credit commitment, such outgoings could prompt questions from an underwriter.
Nicholas Mendes of John Charcol echoed this, stating high outgoings on statements are likely to be queried, but conceded "it's something that someone could cancel."
The Practical Impact on Homebuyers
The potential impact hinges largely on whether lenders delve into an applicant's bank statements. Many brokers note that most banks and building societies no longer conduct line-by-line reviews, meaning the expenditure might not be discovered.
Nevertheless, experts commonly advise prospective buyers to trim non-essential spending in the months before a mortgage application. This includes gym memberships and entertainment subscriptions, which are routinely considered in affordability assessments.
For those on tighter budgets, such as first-time buyers, the effect could be more pronounced. Alexander calculated that a regular £250 monthly payment could reduce a maximum mortgage offer by £10,000 to £20,000 for a buyer on a modest salary.
As the use of private weight loss treatments continues to grow, prospective homeowners are urged to consider how all regular outgoings, including healthcare-related spending, might influence their future borrowing capacity.
