When a Positive Test Became an Appeal

The International Testing Agency notified Ysaora Thibus, the Fédération Française d'Escrime and the Fédération Internationale d'Escrime of an adverse analytical finding for ostarine. Under the FIE Anti-Doping Rules and the World Anti-Doping Code, she was provisionally suspended until the matter was resolved. The notice concerned a potential anti-doping rule violation, not a final sanction.

The case notice also gave Thibus the option of requesting B-sample analysis. Her explanation was that the ostarine had reached her through contamination caused by kissing her then-partner. That account turned the case from a detected substance into a question of transmission, while the provisional suspension remained in place.

On 4 June 2024, the FIE Doping Disciplinary Tribunal found that Thibus bore no fault or negligence and imposed no period of ineligibility. WADA challenged the explanation that kissing with Thibus’s then-partner had caused the positive test. It appealed the tribunal’s decision to the Court of Arbitration for Sport and requested a four-year period of ineligibility.

CAS held an in-person hearing at its headquarters in Lausanne, Switzerland, on 6 March 2025. In the appeal, CAS found it scientifically established that an ostarine dose similar to the dose ingested by Thibus’s then-partner would have left sufficient amounts of ostarine in saliva to contaminate a person through kissing. That finding supplied the scientific basis for considering the contamination explanation within the case.

On 7 July 2025, CAS dismissed WADA’s appeal and upheld the DDT decision. The adverse analytical finding had triggered suspension and a demand for a four-year sanction; the final appellate outcome left Thibus with no period of ineligibility under the decisions described in the proceedings.