By Chris Chavez
October 23, 2025
Marathon world record holder Ruth Chepngetich has been banned for three years by the AIU following her admission to an Anti-Doping Rule Violation regarding the presence and use of Hydrochlorothiazide, a banned diuretic and masking agent in doping. The announcement from the AIU was made public on Thursday morning.
Chepngetich broke the women's marathon world record in 2:09:56 at the 2024 Chicago Marathon. She is the 2019 World Champion and three-time winner of the Chicago Marathon.
The AIU shared that Chepngetich was tested 15 times out of competition and four times in competition in 2024. After she broke the world record, the AIU tested her more as she prepared to race the 2025 London Marathon. Chepngetich struggled in the two races that followed.
The AIU tested her and collected the following samples:
Feb. 28th, 2025 (Out of Competition) – Urine and blood passport
March 8th, 2025 (Out of Competition) – Urine and blood passport
March 9th, 2025 (In Competition at the Lisbon Half, where Chepngetich ran 1:06:20 for second place) – Urine
March 14th, 2025 (Out of Competition) – Urine and blood passport
March 19th, 2025 (Out of Competition) – Urine, blood serum and blood passport
March 26th, 2025 (Out of Competition) – Urine and blood passport
A brief timeline of the investigation:
• March 14, 2025 – Chepngetich tested positive for HCTZ with a concentration of 3,800 ng/mL, far exceeding the WADA reporting threshold of 20 ng/mL. HCTZ works by promoting the elimination of water from the body through increased urine output and can sometimes be used to conceal the presence of other prohibited substances.
• April 16, 2025 – During her first AIU interview, Chepngetich was unable to explain the result. Investigators collected a full list of her supplements and medications, as well as physical samples and a forensic copy of her phone for analysis.
• July 11, 2025 – The AIU confronted Chepngetich with suspicious material from her phone, suggesting potential intentional use. Lab analysis confirmed none of her submitted supplements contained HCTZ.
The AIU found:
– A screenshot of a WhatsApp message she got from another athlete showing pictures of testosterone vials, along with a message asking how testosterone “works.” The text was from April 14th, 2024, which is before she went on to break the marathon world record that fall.
– Messages from 2022, 2023 and 2025 about people working on “programs” that could be related to doping.
– A photo showing a vial and a box of Anavar, which is another banned steroid. This image was from April 29th, 2024.
Chepngetich said she never asked for or responded to the testosterone message and might have taken the screenshot by accident. She also said the other messages were random, possibly from group chats or things forwarded to her without her asking. As for the Anavar image, she said it might have been automatically saved from a group chat, and she didn’t search for it herself.
• July 31, 2025 – Chepngetich changed her story. Two weeks after the AIU charged her in July, she gave a new explanation, saying that on March 12, 2025, she had felt unwell (sweating, weak, and with a fast heartbeat) and took medicine from her housemaid, who’d had similar symptoms. The one pill turned out to be Hydrochlorothiazide, which she didn’t realize was banned. She said she forgot to mention it on her doping control form two days later.
The AIU did not accept this explanation as credible, citing recklessness and indirect intent.
The AIU asked labs to recheck her earlier drug tests. They found that a sample taken on February 28, 2025, which was about two weeks before the positive test, also showed tiny traces of HCTZ, but the amount was too low to count as a violation at the time.
• August 22, 2025 – The AIU issued a Notice of Charge seeking a four-year ban based on indirect intent and lack of a credible explanation. Ordinarily, such an infraction would result in a two-year suspension.
Chepngetich admitted guilt and accepted the sanction within 20 days. As a result, the ban was reduced to three years under ADR 10.8.1 (early admission clause.)
The AIU will continue to investigate the suspicious material recovered from Chepng’etich’s phone to determine if any other violations have occurred.
All of Chepngetich’s results prior to March 14th, including the marathon world record, still stand. Chepngetich broke Tigst Assefa's world record of 2:11:53 set at the 2023 Berlin Marathon. Assefa's world record was ratified on May 23rd, 2024. Chepngetich's world record was ratified on Dec. 11th, 2024.
Chepngetich did not defend her title at the 2025 Chicago Marathon while serving her provisional suspension.
What They Had To Say
AIU head Brett Clothier: “The case regarding the positive test for HCTZ has been resolved, but the AIU will continue to investigate the suspicious material recovered from Chepngetich's phone to determine if any other violations have occurred. In the meantime, all Chepngetich achievements and records pre-dating the 14 March 2025 sample stand."
AIU chair David Howman: “While disappointing for those who put their trust in this athlete, this is how the system is supposed to work. The road-running industry should be commended for collectively funding anti-doping efforts capable of uncovering doping violations committed by elite athletes in their events. The level of testing and investigative activity carried out in this case was possible because of the funding provided to the World Athletics Label Road Race Programme by many races such as the Chicago Marathon, athlete representatives, athletes and four contributing shoe brands, Adidas, ASICS, On and Nike.”
You can read the full press release and detailed decision here.
Chris Chavez
Chris Chavez launched CITIUS MAG in 2016 as a passion project while working full-time for Sports Illustrated. He covered the 2016 Olympics in Rio de Janeiro and grew his humble blog into a multi-pronged media company. He completed all six World Marathon Majors and on Feb. 15th, 2025 finally broke five minutes for the mile.
