ITF 2020 ITF vs Dayana Yastremska

In December 2020 the International Tennis Federation (ITF) has reported an anti-doping rule violation against the Ukrainian tennis player Dayana Yastremska after her A and B samples tested positive for the prohibited substance Mesterolone in a low concentration. After notification a provisional suspension was ordered. The Athlete filed a statement in her defence and she was heard for the ITF Independent Tribunal.

The Athlete admitted the violation, accepted the test results and denied the intentional use of the substance. She asserted with evidence and witness statements that the postitve test was the result of contamination through person-to-person transfer.

At the relevant time she had close physical contact with her boy friend whereas she was unaware that he had used Mesteronolone. The Athlete's boy friend testified that he had ingested Mesteronolone tablets when he had close physical contact with the Athlete shortly before she had out-of-competiton Doping Control.

The ITF contended that the Athlete intentionally had used the prohibited substance and it rejected the Athlete's explanation on how the substance had entered her system.

The Panel considered the evidence in this case and accepts the Athlete's explanation, her corroborating evidence and the testimonies of the expert witnesses. The Panel is satisfied, on the balance of probabilities, that the Athlete has established the source of the prohibited substance.

Therefore the Panel deems on 21 June 2021 that No Fault or Negligence has been established and that no period of ineligibility shall be imposed on the Athlete.

Original document


Legal Source
Decisions International Federations
21 June 2021
Ahern, Susan
Kleiner, Jan
Sever, Peter
Original Source
International Tennis Federation (ITF)
Adverse Analytical Finding / presence
Legal Terms
Case law / jurisprudence
Circumstantial evidence
No Fault or Negligence
No intention to enhance performance
Tennis (ITF) - International Tennis Federation
Analytical aspects
B sample analysis
Doping classes
S1. Anabolic Agents
Medical terms
Person-to-person transfer
Polygraph examination
Document type
Pdf file
Date generated
4 August 2021
Date of last modification
16 August 2021
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