Maria Sharapova revealed on March 7 that she failed a drug test at the Australian Open. According to the five-time Grand Slam tennis champion, she has been legally taking meldonium for her irregular heartbeat and familial history of diabetes since 2006 but the drug became a prohibited substance in January.

Meldonium, also known as mildronate, was added to the World Anti-Doping Agency’s banned list because it is presumed to be used by athletes to enhance their performance. The decision to ban it was approved on Sept. 16, 2015 and came into effect on Jan. 1.

Meldonium, also known as mildronate. Photo from Grindex

Meldonium, also known as mildronate. Photo from Grindex

Grindeks, the Latvian company that produces the drug, claims that meldonium can also improve the physical and mental function of an individual by increasing the blood flow. Additionally, a previous study found that meldonium enhances an athlete’s rehabilitation after exercise, defense against stress and central nervous system functions.

However, it is primarily used for the treatment of ischaemia or the inadequate supply of blood flow to body parts. This can be observed in patients with heart failure or angina pectoris, a sensation of pressure or squeezing kind of chest pain. It is only prescribed to be taken between four to six weeks.

The said drug is only produced in Latvia and only available in Baltic countries and Russia. It is not licensed in the rest of Europe and US.

In the 1980s, meldonium was widely used among Soviet troops to increase their stamina while fighting in Afghanistan. According to The Guardian, Professor Xavier Bigard, scientific advisor to the French Agency Against Doping (AFLD), said that many athletes used the drug at the 2015 European Games in Baku.

Other well-known athletes have also been suspended for using the drug. According to reports, 2013 women’s 1,500 metre running world champion, Abebe Aregawi, also tested positive for meldonium. Ukrainian biathletes Olga Abramova and Artem Tyschcenko, as well as Russian cyclist Eduard Vorganov, Russian ice dancer Ekaterina Bobrova and 2015 Tokyo marathon champion Endeshaw Negesse were also caught using the same substance.

An athlete could apply for TUE or therapeutic use exemption (TUE) that allows players to take a prohibited substance if they need it to treat their health problems without violating the policies. Nevertheless, if proven to violate the rules, the athlete could be banned for up to four years.