Five-time grand slam tennis champion Maria Sharapova has been suspended from the International Tennis Federation for doping.
The news comes after Sharapova announced in March that she had failed a drug test at the Australian Open in January.
According to Sharapova, she had been using the recently banned drug meldonium for the past 10 years — or most of the time she's been a pro tennis champion — because of a variety of medical conditions.
Meldonium is prescribed primarily to treat conditions like heart failure. But Sharapova justified her use of the medicine because of her magnesium deficiency, "irregular" EKG results, and a history of diabetes in her family that put her at a higher risk for the disease — reasons cardiologist Eric Topic told Vox "make no sense at all."
What's more, the AP reported that officials at the Latvian company that makes the drug said it's usually only prescribed for courses of four to six weeks.
Here are five things to know about the drug that got Sharapova into doping trouble.
1) The primary purpose of the drug: treating heart conditions
According to the drugmaker's website, meldonium is primarily used to treat heart-related conditions — like angina pectoris and heart failure — that block blood and oxygen to the heart muscle. The drugmaker also says meldonium can also improve "physical capacity and mental function" in healthy people.
Interestingly, the drug was originally developed as a non-antibiotic growth promoter for animals. "The inventors were granted a U.S. patent (PDF) for this use in 1984 but it does not appear to be sold today for agricultural use," writes David Kroll at Forbes.
2) The drug also increases athletic endurance
A study in the journal Drug Testing and Analysis on the use of meldonium in professional sports finds the drug can lead to "improved rehabilitation after exercise, protection against stress, and enhanced activations of central nervous system functions."
3) The World Anti-Doping Agency only officially banned meldonium this year
Because of evidence that athletes were using the drug, the World Anti-Doping Agency had been monitoring meldonium since 2015. It added the drug to its list of banned substances on January 1, 2016.
Meldonium has been classified by the agency as an S4 substance, along with other hormone and metabolic modulators. (Many of these drugs either interfere with hormone function or regulate blood sugar in the body.)
Sharapova said she did not read the email memo that would have informed her about the recent ban.
4) It's popular in Baltic countries and was once used by Russian troops as a stamina enhancer
The drug was developed in Latvia and is currently made by the drug company Grindeks. It's used primarily in Baltic countries like Latvia, as well as Ukraine, and Poland. (Almost all the clinical evidence on the drug is published in Polish and Russian clinical journals.) But in the 1980s, the AP reports, it was widely used among Russian troops to enhance their stamina while fighting in Afghanistan.
The FDA has not approved the drug for sale in the US, nor has the European Medicines Agency.
5) Sharapova is not the first athlete to get slammed for using this drug
According to the Sydney Morning Herald, other athletes have been slapped on the wrist for using the drug this year, which makes Sharapova's claim about not knowing that it was recently banned seem dubious.
As sports journalist Ronny Lerner notes, "Two Ukrainian biathletes and Russian cyclist Eduard Vorganov have already been caught as well as Russia's Ekaterina Bobrova, who is a European champion ice dancer."
The New York Times reports that in October, before the WADA ban went into effect, an anti-doping group found meldonium in the urine samples of 182 of 8,300 athletes.