ITA Finds Bella Sims Had “No Fault Or Negligence” For Positive Drug Test After Investigation

U.S. Olympian Bella Sims, 19, accepted a “no fault or negligence” finding from the International Testing Agency (ITA) after testing positive for the banned substance Hydrochlorothiazide (HCTZ) last fall, the agency reported on Monday, Mar. 31.

As the investigation returned a finding of “no fault or negligence”, the ITA did not impose any sanctions on Sims.

The ITA reported that a sample collected from Sims during an unannounced out-of-competition doping test on September 29, 2024, returned an adverse analytical finding for HCTZ. The drug is a diuretic that’s considered a specified substance under class S5 Diuretics and Masking Agents on the World Anti-Doping Agency (WADA) Prohibited List.

While diuretics are commonly prescribed to treat hypertension and cardiovascular disorders, the United States National Institute of Health (NIH) states that they can cause rapid weight loss and act as a masking agent for other prohibited substances which is why they are banned in sports. 

The ITA stated “during the results management proceedings, the athlete was able to establish that the presence of HCTZ in her sample was caused by the intake of an anti-inflammatory prescription medication, which was confirmed to be contaminated with the banned diuretic. This permitted medication did not list HCTZ on its label…however, laboratory analyses subsequently conducted on the medication tablets confirmed the HCTZ contamination.” 

The Aquatics Integrity Unit (AQIU) noted in its statement on the decision that Sims declared the use of this medication on the doping control form during the unannounced drug test. 

The “no fault or negligence” decision means the athlete was able to establish they “did not know or suspect, and could not reasonably have known or suspected even with the exercise of utmost caution, that [they] had used or been administered the Prohibited Substance.” Unless the athlete proves mitigation factors, including “no fault or negligence” the default period of ineligibility for a case like this is two years. 

The sample wasn’t collected during the competition, so none of Sims’ results were disqualified.

Sims posted on her Instagram about the decision. 

“It was announced today by World Aquatics that I have been cleared of any wrongdoing after a full investigation determined I was not at fault for the presence of a banned substance called Hydrochlorothiazide detected in my urine sample collected on September 29, 2024. World Aquatics’ investigation found that the banned substance was in a contaminated medicine I was prescribed after being diagnosed with a torn labrum in my hip. Until this happened to me, I never understood that prescription medicine could be contaminated with substances not listed on the label. This has been a very stressful time for me, but I am grateful to my family, the University of Florida, and World Aquatics for supporting me and standing by me.” 

The NCAA is not a WADA signatory, so Sims was still eligible to compete at NCAA events during the 2024-25 season. Most recently, Sims competed at the 2025 Women’s NCAA Division I Championships, placing second in the 100 and 200 backstroke. Her 34 points were the most by a Gator swimmer at the meet, helping Florida to a 6th place overall finish. 

While the ITA and World Aquatics now consider the case closed, the parties with a right of appeal—for example, WADA or the United States Anti-Doping Agency (USADA)—may challenge the decision in the Court of Arbitration of Sport (CAS) if they choose. 

Sims is a Tokyo Olympian. As one of the youngest members of that U.S. roster, she won a silver medal as part of the women’s 4×200 freestyle relay team. She’s won two Worlds medals as part of that relay, including gold at the 2022 World Championships. In 2023, she won silver as part of the mixed 4×100 freestyle relay as well.