The lender is now accepting remortgage applications up to a maximum loan to value (LTV) of 60 per cent.
Borrowers require a minimum equity of £300,000 in London, £250,000 in the South East and £200,000 across the rest of the UK.
Rates are the same as capital repayment, staring from 1.29 per cent.
Repayment will be restricted to the sale of the main residence only, with part interest-only and part capital repayment allowed following the same criteria.
Borrowers will also need a minimum income of £75,000 or £100,000 for joint applications.
It is the first time in eight years the society has offered interest-only deals.
The launch comes after Mortgage Solutions last month revealed Nationwide was planning to re-enter the market.
Henry Jordan, Nationwide’s director of mortgages (pictured), said: “As the UK’s second largest lender, it is natural that we continue to look at ways we can support the mortgage market.
“At almost seven per cent, interest only remains an important part of the market, which is why we are launching this new product, initially via brokers.
“During these unprecedented times, it is important to continue offering a variety of options and flexibility to homeowners and, by adding interest only, we are providing access to our standard product range to applicants with good equity.”
Greg Cunnington, director of lender relationships and new homes at Alexander Hall, added: “It is really positive to see Nationwide returning to the interest only market especially when clients, now more than ever, need the widest range of available options.
“Interest-only mortgages are a core part of the holistic advice discussion for intermediaries and, I’m sure I speak for many of them when I say, I’m delighted to see Nationwide showing their support in this way.”