Kenyan marathon champion Peres Jepchirchir faces provisional ban after EPO positive

Kenyan distance runner Peres Jepchirchir, the reigning Olympic and world marathon champion, has been provisionally suspended by the Athletics Integrity Unit (AIU). The suspension follows an adverse analytical finding for erythropoietin (EPO) in an out-of-competition sample collected in Kenya. The AIU announced the provisional ban on Friday, stating that the sample was taken prior to Jepchirchir’s victory at the Sydney Marathon.

Jepchirchir, who is 33 years old, won the Sydney race on 30 August 2026 with a time of two hours, 18 minutes, and 31 seconds. She finished more than three minutes ahead of her compatriot, Irene Chepet Cheptai. The positive test for EPO, a substance that stimulates the production of red blood cells to enhance oxygen delivery to muscles, has led to her immediate provisional suspension from competition. The sample in question was collected while she was in Kenya before travelling to Australia for the event.

Background

Peres Jepchirchir is one of the most decorated female marathon runners in history. Her major victories include the Olympic gold medal at the 2020 Tokyo Games and the World Championships title in September 2025, also held in Japan. She has also claimed major marathon victories in New York in 2021, Boston in 2022, and London in 2024. Additionally, she previously held the women’s half-marathon world record, a title she broke in 2017 and on three occasions in 2020.

The current suspension adds to a long history of doping cases involving Kenyan athletes. More than 140 Kenyan athletes have been sanctioned since the establishment of the AIU in 2017. EPO is a natural substance produced by the kidneys, but when injected, it is detectable in urine or blood only for a short period. Its use is prohibited in athletics as it provides an unfair physiological advantage by increasing the oxygen-carrying capacity of the blood.

Why it matters

The provisional ban raises significant questions about the integrity of recent major marathon results, particularly given Jepchirchir’s dominant performance in Sydney. Her agent, Gianni Demadonna, issued an emailed statement expressing that Jepchirchir feels terrible about the situation. He stated that it is only right for an athlete who uses performance-enhancing drugs to be disqualified. The reaction from the broader athletics community has been mixed. Kara Goucher, an Olympic 10,000 metres silver medallist and former whistleblower in the Nike Oregon Project case, expressed sadness for the athlete but noted that she was not surprised by the finding. Goucher commented that much of what she observes in the sport is difficult to believe, reflecting a widespread skepticism regarding doping controls in the discipline.

The case highlights ongoing challenges in detecting and preventing doping in long-distance running. The short detection window for EPO makes out-of-competition testing a critical tool for the AIU. The provisional nature of the ban means that Jepchirchir’s results from the Sydney Marathon and potentially other recent competitions may be subject to further review and potential disqualification if the case is upheld.

What happens next

Jepchirchir is currently under a provisional ban, which prevents her from competing in sanctioned events while the case is investigated. The AIU will continue its proceedings to determine the final outcome of the doping violation. Athletes in such cases are typically given the opportunity to present their case and explain how the prohibited substance entered their system. The final decision will depend on the evidence gathered during the investigation and any hearings that may be held.