How sanctions work

Strict liability

Under the anti-doping system an athlete is responsible for any prohibited substance found in their sample, whether or not they meant to take it. Intent and fault matter for the length of the ban, not for whether a violation occurred.

• USADA's chief executive said in July 2024 that "the global anti-doping system is based on the principle of strict liability".¹
• USADA said that even when contamination is proven, agencies must still find a violation, disqualify results and make a public announcement.¹
• WADA warns that "Even an all-natural supplement could contain a prohibited substance", and that an athlete who blames a supplement must establish the exact origin of the substance.²
• USADA tells athletes that "The use of any supplement is at your own risk."³
• In the Jannik Sinner case the tribunal found No Fault or Negligence, so there was no ban, but his Indian Wells 2024 results, prize money and ranking points were still disqualified.⁴

Sources

1. USADA, Statement from USADA CEO Travis T. Tygart on contamination cases and the requirement of transparency (30 July 2024)
2. WADA, At a Glance: Anti-Doping Overview (March 2022)
3. USADA, Supplement 411 (22 May 2026)
4. International Tennis Integrity Agency, Independent tribunal rules No Fault or Negligence in case of Italian player Jannik Sinner (20 August 2024)