Nine lenders have increased the cost of their personal loans by as much as four per cent as the cost of the credit crunch is transferred to the consumer.
Online resource Moneyfacts.co.uk highlighted that the last nine months have seen a "steady increase" in the interest rates charged on loans.
Lisa Taylor, analyst at Moneyfacts.co.uk, said: "With increasing uncertainty in the financial markets, rising levels of bad debt and a year of interest rate rises putting pressure on our disposable incomes, its comes as no surprise to see lenders increasing their lending margins."
She said credit had become a far riskier business recently.
Ms Taylor also offered advice for borrowers trying to consolidate their loans, saying they should cut off their other sources of credit such as overdraft, to help avoid temptation.
Thomas Charles published research earlier this year which claimed 8.3 million Britons were in serious debt and struggling with repayments.
It discovered 25 per cent of adults with more than £10,000 of debt reported having regular trouble making repayments.