Ruth Chepng’etich, the Kenyan runner whose blistering marathon last fall stunned and unsettled the running world, has been provisionally suspended for doping.
On Wednesday, the Athletics Integrity Unit (AIU) announced that Chepng’etich tested positive for hydrochlorothiazide (HCTZ), a banned diuretic classified as a “Specified Substance” under the World Anti-Doping Code. The AIU collected the sample on March 14, 2025, and reported the result on April 3. The sample, which had an estimated concentration of 3800 ng/mL, was reported as 190 times higher than the allowed limit of 20 ng/mL.
While diuretics like HCTZ don’t enhance performance directly, they are commonly used to mask the presence of other banned substances. In this case, Chepng’etich was not immediately suspended but opted for a voluntary provisional suspension beginning April 19 as the investigation unfolded.
A provisional suspension temporarily bars an athlete from competition while their case is under review, but Chepng’etich maintains the right to a hearing before a disciplinary tribunal, which hears and decides on cases of misconduct.
The positive test comes nine months after Chepng’etich won the 2024 Chicago Marathon in October, stunning the world by becoming the first woman to run 26.2 miles in under 2 hours and 10 minutes. Her time of 2:09:56 shattered the previous world record of 2:11:53 by Ethiopia’s Tigst Assefa in Berlin the year before. Chepng’etich went home with $100,000 after her win in Chicago. She also won Chicago in 2022.
At the time, Chepng’etich’s performance incited both awe and skepticism among the running community. She averaged 4:58 per mile, significantly faster than elite norms, and finished well ahead of the runner-up by nearly eight minutes.
Chepng’etich’s time was just 7.2% slower than the men’s world record–held by Kelvin Kiptum at 2:00:35–which was far narrower than the typical 10-11% sex gap seen across running events.
During the post-race press conference, Robert Johnson from LetsRun, a running news website, questioned Chepng’etich on the growing concern around doping in Kenya.
“Ruth,” he asked, “unfortunately in recent years there’s been a number of doping positives in Kenya. What would you say to someone who says when they see 2:09:56, ‘This is too good to be true. I have questions about it’?”
Chepng’etich replied: “I don’t have any idea.”
When Johnson followed up, asking what she would say to people who insisted that she had been doping, Chepng’etich answered: “You know people must talk but… people must talk so I don’t know.”
The AIU declined a request for further comment. A confirmed anti-doping violation involving a specified substance typically carries a two-year suspension, though it can differ depending on circumstances.
Emily Sisson, the U.S. marathon record holder who finished second behind Chepng’etich at the 2022 Chicago race, called the doping news “a punch in the gut.” She wrote that runners have to race with an “ignorance is bliss” mentality just to stay hopeful.
