The Society of St Vincent de Paul (SVP) charity is calling for all licensed moneylenders to carry a tobacco-style warning on their advertising.
It says they should also have a high cost loans warning on their literature
In a submission to the Department of Finance, SVP says it is "astonishing" that no such warning is currently required.
According to the Central Bank, while moneylenders are required to provide information about the high cost nature of the loan to their customers, this is typically provided in the moneylending agreement which must be signed by the customer.
However it is not a requirement for the advertisement of licensed moneylending loans.
The society says that 'Warning: This is a high cost loan' should be on all moneylending advertisements and literature - and the warning should also point out that alternatives to high cost loan offerings may be available, and that people should check their options before borrowing.
There are an estimated 330,000 customers of moneylenders in Ireland.
SVP also believes that there should be a statutory maximum cost of credit, which can be charged by a moneylender, and that consumers should have better access to sources of low-cost credit.
SVP says this could be achieved through the introduction of a statutory interest rate cap.
Caroline Fahey is the SVP's head of social justice: "This should be done at the same time and in conjunction with the introduction and strengthening of other measures to protect vulnerable customers of moneylenders.
"These other measures should include better access to sources of low cost credit for low income households, enforcement of the Consumer Protection Code for Moneylenders and better protection of customers of moneylenders, including better information, financial education and more inclusive mainstream banking services.
"The main considerations for SVP and the people we assist are the total cost of credit, including charges.
"How manageable the repayments are, the alternatives available, the provision of clear information which will allow customers to make informed decisions about taking out moneylender loans and the introduction, strengthening and monitoring of measures to protect customers of moneylenders".