Kenyan marathon star Peres Jepchirchir has been provisionally suspended by the Athletics Integrity Unit (AIU) after an out-of-competition sample collected before her victory at the Sydney Marathon returned an adverse analytical finding for erythropoietin (EPO), a prohibited substance.
The AIU announced the suspension on Friday, October 23, 2026, saying the sample was collected in Kenya ahead of the Sydney Marathon, which Jepchirchir won on August 30.
The provisional suspension prevents the 33-year-old athlete from competing while the case proceeds under the sport’s anti-doping rules. It is not, however, a final determination that she committed an anti-doping rule violation.
EPO is a hormone that stimulates the production of red blood cells, which carry oxygen around the body. Its use to enhance athletic performance is prohibited because increasing red blood cell production can improve oxygen delivery to muscles and potentially boost endurance.
Jepchirchir’s suspension has sent shockwaves through international athletics, given her achievements on the global marathon circuit and her status as Kenya’s reigning women’s world marathon champion.
Her representative, Gianni Demadonna, expressed disappointment over the development in a statement reported by international media.
“I can only say that I feel terrible about what happened and I think it’s only right that an athlete who uses the performance enhancing drugs should be disqualified,” he said.
The case follows Jepchirchir’s impressive victory at the 2026 Sydney Marathon, where she completed the women’s race in two hours, 18 minutes and 31 seconds. She finished more than three minutes ahead of compatriot Irine Cheptai, who placed second.
The Sydney victory added to an already distinguished career. Jepchirchir won the women’s marathon at the Tokyo Olympic Games in 2021 and claimed the world marathon championship title in Tokyo in 2025.
She has also won four major international marathons, taking the New York City Marathon in 2021, the Boston Marathon in 2022, the London Marathon in 2024 and the Sydney Marathon in 2026. She is also a former half-marathon world record holder.
The suspension comes amid continued scrutiny of anti-doping enforcement in Kenya, a country renowned for producing elite long-distance runners.
According to reports by Agence France-Presse, more than 140 Kenyan athletes have been suspended or banned by the AIU since 2017. The cases have raised concerns about doping prevention, athlete support systems and the protection of Kenya’s reputation in international athletics.
Earlier this month, the World Anti-Doping Agency (WADA) called for stronger cooperation between sporting authorities and Kenyan law enforcement agencies to tackle those involved in producing, supplying and trafficking prohibited performance-enhancing substances.
Jepchirchir’s case also follows the high-profile suspension of fellow Kenyan marathon runner Ruth Chepngetich, who received a three-year ban after admitting anti-doping rule violations involving hydrochlorothiazide, a prohibited diuretic. Chepngetich’s marathon world record, set before the positive test, remained on the books.
The current case against Jepchirchir will be handled through the established anti-doping process. Further proceedings will determine the outcome and any potential consequences under the applicable rules.
For now, the provisional suspension means one of Kenya’s most decorated distance runners cannot compete while the case remains unresolved. The outcome will be closely watched by athletics officials, fellow athletes and supporters of the sport, particularly as Kenya prepares to host the 2029 World Athletics Championships in Nairobi.