Kenyan athlete Ruth Chepng'etich, the world marathon record holder, has been banned for three years by the Athletics Integrity Unit (AIU) after admitting to using the prohibited substance Hydrochlorothiazide (HCTZ). Her urine sample, taken on March 14, 2025, showed concentrations of about 3,800 ng/mL. The ban was reduced from four years due to her early admission.
Ruth Chepng'etich, the 31-year-old Kenyan athlete and three-time Chicago Marathon winner, who set the women's world record of 2:11:53 in 2024, has admitted to anti-doping rule violations (ADRVs). The Athletics Integrity Unit (AIU) announced the three-year ban on October 23, 2025, following a urine sample collected on March 14, 2025.
Hydrochlorothiazide (HCTZ), a diuretic often used to mask other banned substances, has a WADA reporting threshold of 20 ng/mL. Chepng'etich's sample showed approximately 3,800 ng/mL, prompting an AIU investigation that included an initial interview on April 16, 2025, where she could not explain the result. Investigators gathered her supplements, medications, and mobile phone, all of which tested negative for the substance.
In a July 11, 2025 interview, evidence from her phone raised suspicions of intentional use. On July 31, 2025, she changed her account, stating she took her domestic manager's medication two days before the test without verifying its contents. The AIU deemed this reckless and indicative of indirect intent, initially warranting a four-year ban, but it was reduced to three years after her admission on September 10, 2025, under ADR 10.8.1.
"The case regarding the positive HCTZ result has been closed, but the AIU will continue to investigate the suspicious information found on Chepng'etich's phone to determine if there are other violations," said AIU head Brett Clothier. Chair David Howman added, "no one is above the rules." Her records and achievements before March 14, 2025, remain valid.