The redesigned site will offer fresh commercial opportunities, including leaderboards and larger-sized multiple purpose units (MPUs).
Editorial changes to the website include enhanced fashion coverage and extended video content, plus new hair and news channels.
Other new features include mircrosites dedicated to key events and a third party-powered online shopping section offering designer and high-street products.
The new-look site will be promoted across a number of IPC's women's magazines, including Marie Claire, Essentials and Now, along with advertising on websites such as Marieclaire.co.uk and Nowmagazine.co.uk.
The InStyle.co.uk website was launched in May 2007 and the change is its first major overhaul since its creation.