Last summer, U.S. sprinter Tyson Gay was poised to take the crown from Jamaica’s Usain Bolt at the 2013 world championships in Moscow. But after Gay failed a drug test, it seemed like yet another sob story of a promising athlete’s fall from grace.

ProPublica’s David Epstein explains in his latest report that Gay was likely done in by an obscure cream given to him by his anti-aging specialist, Clayton Gibson III. It clearly listed testosterone and DHEA among other ingredients which are banned in Olympic sports – demonstrating how unconventional health practitioners are often unfamiliar with the intricacies of drug exams. “I don’t have a sabotage story. I don’t have any lies … I basically put my trust in someone and I was let down,” Gay said.

Epstein joins the podcast this week to discuss how Gay’s case provides a view of the “slipshod medical underworld of top-level sport”; how the hormone replacement industry has grown tremendously across all sectors, not just among athletes; and how the long-term effects of these supplements, creams and potions still remain a mystery: “The test subjects are the people using it right now,” Epstein says.

You can listen to this podcast on iTunes and Stitcher. And for more on this investigation, read our co-published report with Sports Illustrated: Cheat Sheet: The Tyson Gay File.