Richie has been featured in several fashion blogs and magazines such as Harper's Bazaar, Seventeen, Lucky, Marie Claire, Elle, InStyle, Paper, Company, Nylon, Tatler, Flare, and Teen Vogue. She has also modeled for Australia's Vogue and Elle; US' People, Stuff, Blender and Hollywood Reporter; Mexico's Marie Claire and UK's Glamour. Richie has been the face of Bongo Jeans and Jimmy Choo advertising campaigns. In April 2007, Richie announced plans to start a jewelry, accessories, and sunglasses line along with a perfume and style book. In October 2008, she debuted a jewelry line, named House of Harlow. The line became available at Kitson's online boutique. In spring 2010, the line was extended to include apparel and shoes. House of Harlow later became a lifestyle brand including eyewear, home fragrance, and accessories.
In March 2007, Richie was taken to the hospital for dehydration. On March 21, her representatives announced she was diagnosed with hypoglycemia.
In November 2007, Richie and her husband Joel Madden created The Richie Madden Children's Foundation in support of disadvantaged young mothers and children. She has been involved with the Red Cross, UNICEF, Elton John AIDS Foundation, Charlize Theron Africa Outreach Project, Dana-Farber Cancer Institute, March of Dimes, Playing for Change, Small Steps Project, and Baby2Baby. Richie is a board member of Baby2Baby.
In 2007, Richie and Madden donated 100 baby gifts to expectant mothers at Los Angeles Free Clinic, through The Richie Madden Children's Foundation. In May 2008, Richie and Madden shot a UNICEF public-service announcement to generate aid for the cyclone-devastated Myanmar. Richie and Madden have also written blogs on the UNICEF website and encouraged people to help children in need. Richie, Joel and Benji Madden along with UNICEF held a fundraiser for the Tap Project in March 2009. They sold 143 water pumps to bring water directly to the villages and raised $100,000. Esprit donated 10% of all the sales on April 2, 2009, at their newly opened 3rd Street Promenade store to The Richie-Madden Children's Foundation. The Richie-Madden Foundation specially designed "Cup with a Cause" for 7-Eleven. It was a part of their charity-focused coffee campaign in February 2010. During 2010 the Foundation worked together with Beyond Shelter, a non-profit organization devoted to providing shelter for homeless families in Los Angeles.