Banned substances in baseball in the United States

Banned substances in baseball has been an ongoing issue for Major League Baseball. Several players have come forward in recent years to suggest that drug use is rampant in baseball. David Wells stated that "25 to 40 percent of all Major Leaguers are juiced".Jose Canseco stated on 60 Minutes and in his tell-all book Juiced that as many as 80% of players used steroids, and that he credited steroid use for his entire career.Ken Caminiti revealed that he won the 1996 National League MVP award while on steroids. In February 2009, after reports emerged alleging that Alex Rodriguez tested positive for steroids in 2003, a year in which he was American League MVP, he admitted to having used performance-enhancing drugs (PEDs) between 2001 and 2003.Mark McGwire, dogged by allegations of PED use for years, admitted in January 2010 that he had used steroids and human growth hormone off and on for over a decade, including in 1998 when he set the single-season home run record.

Players have attempted to gain chemical advantages in baseball since the earliest days of the sport. In 1889, for example, pitcher Pud Galvin became the first baseball player to be widely known for his use of performance-enhancing substances. Galvin was a user and vocal proponent of the Brown-Séquard Elixir, a testosterone supplement derived from the testicles of live animals such as dogs and guinea pigs.

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