Television personality, international speaker, author, and osteopathic physician, Reef is best known as the host of the Court TV television show House of Clues, the host of the Discovery Fit & Health television show Broken Minds, a recurring guest expert on the television show Outrageous Acts of Psych, from Discovery Science, and the comedic host, writer and producer of Karim Madness.

Karim has appeared on Oprah, Dr. Oz, Dr. Phil, The Today Show, Chelsea Lately, and regularly appears on CNN as a medical and psychiatric commentator. He has written articles for the Huffington Post, Oprah.com, and Fox.com. He has also had minor roles in television shows like Lost Transmissions (2019) and Veep (2017).

In 2004, Karim was named one of "The Sexiest Men Alive" by People magazine.