A French fencer has been cleared of doping allegations after arguing that she unknowingly ingested a banned substance via kissing.
Ysaora Thibus, the 2022 world champion in women’s foil, had been facing a four-year ban from competition after she tested positive in January 2024 for ostarine, an anabolic agent that has been prohibited by the World Anti-Doping Agency (WADA) since 2008. She argued that the substance had entered her body via kisses with her then-romantic partner, U.S. fencer Race Imboden.
‘The CAS Panel considered the evidence and noted that it is scientifically established that the intake of an ostarine dose similar to the dose ingested by Ms. Thibus’ then partner would have left sufficient amounts of ostarine in the saliva to contaminate a person through kissing,’ CAS said in a statement announcing the ruling.
‘The CAS Panel ruled that the (doping rules violation) for the presence of ostarine was not intentional, and that it is not questionable that Ms. Thibus bears no fault or negligence.’
WADA spokesperson Andrew Maggio said the organization was ‘disappointed by the outcome’ of the case but declined further comment.
‘WADA challenged the scenario presented by the athlete based on the facts and science of this particular case,’ he wrote in an email.
Thibus, 33, has been under scrutiny for the better part of 18 months − including at the 2024 Paris Olympics, where she had been expected to be among France’s brightest stars.
Thibus was suspended by the International Fencing Federation (FIE) immediately after her positive test in early 2024, then cleared by the federation’s disciplinary panel in May 2024 − which opened the door for her to compete in Paris a few months later, pending appeal. She had been expected to vie for a medal but was upset in the round of 32.
Along the way, WADA exercised its right to appeal the case to CAS, which generally serves as the final arbiter of sports disputes. CAS heard the case this spring and determined that ‘contamination through kissing’ was a plausible explanation. Experts considered the amount of ostarine in the supplement that Imboden was taking, how the substance could spread via saliva and the cumulative effects of such exposure over an extended period of time.
‘At no time did we deviate from our course,’ Thibus’ attorney, Joëlle Montlouis, told French news outlet L’Equipe. ‘From the first instance to the (CAS hearing), we maintained the same line, the same backbone, faithful to the reality of the facts.’
Thibus’ kissing defense is one of several novel explanations that athletes have offered for how and why banned substances got into their bodies. In recent years, some of the most newsworthy contamination cases have revolved around food. Russian figure skater Kamila Valieva famously claimed she accidentally ingested the banned substance trimetazidine through a strawberry dessert given to her by her grandfather, while a group of Chinese athletes said they tested positive for metandienone, an anabolic steroid, after eating contaminated hamburgers.
Contact Tom Schad at tschad@usatoday.com or on social media @tomschad.bsky.social.
