Maria Sharapova, a five-time Grand Slam champion and the world's highest-paid female athlete, admitted that she failed a drug test at the Australian Open in January. She tested positive for meldonium, a recently banned substance that she said she had taken since 2006 for health issues. She will be provisionally banned by the International Tennis Federation on March 12. Click through the gallery to see other athletes accused of using drugs to boost their careers.
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In February, New York Mets pitcher Jenrry Mejia became the first player to be permanently suspended by Major League Baseball after he tested positive for a performance-enhancing substance. MLB said Mejia tested positive for boldenone, an anabolic steroid that athletes use to increase muscle mass.
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New York Yankees slugger Alex Rodriguez confessed to using performance-enhancing drugs in a meeting with the Drug Enforcement Administration in January 2014. Rodriguez told DEA investigators that he had used banned substances, including testosterone cream, testosterone gummies, and human growth hormone, between late 2010 and October 2012. He was suspended for the entire 2014 season.
Olympic sprinter Tyson Gay was banned for one year after he tested positive for a prohibited anabolic steroid in 2013. The four-time U.S. champion in the 100 meters received a reduced punishment from the two-year suspension standard for cooperating with authorities. The 4x100 relay team he was on was stripped of the silver medal it won in the 2012 Olympics. Gay returned to racing in 2014.
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Ryan Braun of the Milwaukee Brewers admitted to using performance-enhancing drugs in 2011, the year he was National League MVP. He said he took a cream and a lozenge with banned substances while recovering from an injury.
Mixed martial arts fighter Alistair Overeem failed a random drug test in 2012 and admitted to injecting himself with a substance that contained testosterone, prescribed for a rib injury. He was suspended for nine months.
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Barry Bonds, baseball's all-time home run leader, was convicted of an obstruction charge in 2011 after he impeded a grand jury investigating the use of performance-enhancing drugs. Bonds had testified that he thought his personal trainer was giving him arthritis balm and flaxseed oil, not steroids or testosterone.
Houston Texans linebacker Brian Cushing was suspended for four games after testing positive for a drug called human chorionic gonadotropin in 2010.
Cyclist Floyd Landis admitted in 2010 to using performance-enhancing drugs for most of his career. Landis used the red-blood-cell booster erythropoietin, known as EPO, along with testosterone, human growth hormone and frequent blood transfusions. He was stripped of his 2006 Tour de France win and suspended from cycling for two years.
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In 2008, Olympic track star Marion Jones was sentenced to six months in prison for lying to federal prosecutors investigating the use of performance-enhancing substances.
Former New Orleans Saints defensive lineman Charles Grant tested positive for banned substances in 2008 and was suspended for the rest of the season.
Retired New Orleans Saints running back Deuce McAllister tested positive for a banned diuretic in 2008.
Shawne Merriman, then of the San Diego Chargers, was suspended for four games after testing positive for steroids in 2006. He retired in 2013 after eight NFL seasons.