The 31-year-old television personality has expanded her fashion line Downtown Glam for the American department store Kohl's to include garments to suit "every woman".
The 'The Hills' alumni spoke about her latest venture to Justjared.com, she said: "I thought, 'What better time to add Plus?'"
The reality star and fashion designer decided to create the collection because she wanted females to have "access to cute outfits" regardless of their shape or size.
She said: "Every woman, no matter her shape and size, should have access to cute outfits for a great girls' night out."
Lauren handpicked YouTube star Loey Lane to star in the campaign and represent her brand because she though the online sensation was the "perfect model" for the commercials.
She said: "Loey was the perfect model for this.
"What better way to introduce Plus than have the beautiful Loey Lane be our model."
Lauren has revealed she would usually front the campaigns for her Lauren Conrad for Kohl's capsules but at the time she was pregnant with her first child, Liam, who she gave birth to in July this year.
The style icon explained: "Typically I shoot the campaigns for my Lauren Conrad Kohl's collections but since I was heavily pregnant at the time I couldn't."
And the 'Laguna Beach' star is set for a busy year ahead as she is set to showcase 35 designs from her LC Lauren Conrad Runway Collection for the first time at New York Fashion Week on Saturday.
Speaking previously about her fashion week debut, she said: "I am so excited to announce that I'll be debuting a new @LCLaurenConrad collection at #NYFW on September 9! We have been hard at work for months and I am so excited to finally be able to tell everyone!#LCRunway ."