Peres Jepchirchir, the 33-year-old Kenyan marathon runner and reigning world champion, has been provisionally suspended following a positive doping test, the Athletics Integrity Unit (AIU) announced on Friday. The suspension comes after an out-of-competition sample collected in Kenya tested positive for erythropoietin (EPO), a banned blood-boosting substance. Jepchirchir remains barred from competition while the case is under investigation.
Jepchirchir, who won the women’s marathon gold at the Tokyo Olympics in 2021 and claimed the world title last year, also secured victory at the 2022 Boston Marathon and most recently at the Sydney Marathon in August. She is a former world record holder in the half marathon. Her representative declined to comment on the matter.
The Boston Athletic Association (BAA), organizer of the Boston Marathon, said the provisional suspension does not affect previous Boston Marathon results. In a statement, the BAA emphasized its commitment to anti-doping measures to ensure fair competition in line with guidelines from World Athletics, the World Anti-Doping Agency (WADA), and the United States Anti-Doping Agency. The organization stated it would continue to monitor developments in the AIU investigation.
Jepchirchir’s suspension adds to ongoing doping concerns involving Kenyan distance runners. Kenya, recently awarded the 2029 World Athletics Championships—the first time the event will be hosted by an African nation—has faced repeated scrutiny over performance-enhancing drug use among its elite athletes. In recent years, several Kenyan runners have been banned or had titles stripped due to doping violations, including Ruth Chepng’etich, who received a three-year ban in 2025 for a banned diuretic, and Albert Korir, banned for five years after winning the 2021 New York Marathon. Additionally, two Kenyan women, Rita Jeptoo and Diana Kipyokei, had their Boston Marathon victories invalidated following positive tests, although Jeptoo’s earlier wins in 2006 and 2013 remain recognized.
World Anti-Doping Agency President Witold Bańka recently called on Kenya to adopt a “more determined approach” to maintain its credibility in athletics, stressing the importance of a strong culture of clean sport and zero tolerance for doping.
The announcement of Jepchirchir’s provisional suspension came one day after the AIU issued a six-year ban to Ethiopian marathoner Ruti Aga. Aga was found to have tested positive for a banned substance and then submitted a falsified prescription from a clinic that was later determined to be nonexistent.