Novitzky grew up in Burlingame, California and graduated from Mills High School in Millbrae in 1986. Novitzky enrolled at the University of Arizona on a track and field scholarship, before transferring to Skyline College. Novitzky played two seasons of basketball at Skyline but just one game in his second season due to injuries. In 1989, Novitzky transferred to San Jose State University on a basketball scholarship. For the San Jose State Spartans, Novitzky played two games as a reserve forward in the 1989–90 season, Stan Morrison's first as head coach. Again, injuries limited Novitzky's playing time to those two games. Novitzky graduated from San Jose State in 1992 with a degree in accounting.
His investigations have concerned Marion Jones, Tim Montgomery, Victor Conte, Dana Stubblefield, Tammy Thomas, Melky Cabrera, Trevor Graham, Roger Clemens, Barry Bonds, Bay Area Laboratory Co-operative, Kirk Radomski, Bill Romanowski, Justin Gatlin, Jose Canseco, Floyd Landis, Tyler Hamilton and Lance Armstrong.
On May 20, 2010, the New York Daily News reported that Novitzky was involved in an investigation into performance enhancing drug use on Lance Armstrong's Tour de France teams, and that Armstrong's former teammate Floyd Landis was cooperating with the investigation. Previously, Marion Jones, a track and field Olympian winner, pleaded guilty in October 2007 to making false statements to Novitzky. Novitzky was also able to convince Kirk Radomski, a former New York Mets club house worker, to become a government informer. Radomski has now been convicted of distributing anabolic steroids to over a dozen Major League Baseball players.
Novitzky was also a major source of information in the Mitchell Report about doping in Major League Baseball.
In his book The Secret Race, former professional cyclist Tyler Hamilton wrote that Novitzky drove a "bulldozer" through the sport of cycling in uncovering details about the pervasive use of performance enhancing drugs.
Starting in April 2015, Novitzky began working for the UFC as their Vice President of Athlete Health and Performance. Within this role, Novitzky will spearhead anti-doping efforts within the organization.
Novitzky has been, at times, criticized by certain defendants in steroid-related cases who perceive that he is biased and unfair. However, Novitzky, in multiple cross examinations, including during the federal perjury investigation of Roger Clemens, has proved to be a credible government witness. He has often been compared to famed IRS investigator Eliot Ness.