World Champion Peres Jepchirchir Provisionally Suspended After EPO Test

Kenyan marathon star Peres Jepchirchir has been provisionally suspended by the Athletics Integrity Unit (AIU) after an out-of-competition sample tested positive for erythropoietin (EPO), a substance that can enhance athletic performance.

The Olympic and World Championships marathon gold medallist provided the sample in Kenya before competing in the Sydney Marathon on 30 August 2026. She went on to win the race in two hours, 18 minutes and 31 seconds.

The positive test has placed the celebrated long-distance runner under scrutiny, although the provisional suspension does not in itself constitute a final determination of an anti-doping violation.

EPO, short for erythropoietin, is a hormone naturally produced by the kidneys. It stimulates the production of red blood cells, which carry oxygen throughout the body and deliver it to working muscles.

Increasing red blood cell levels can improve the amount of oxygen available to muscles during endurance exercise. However, the use of EPO as a performance-enhancing drug is prohibited in athletics.

When administered artificially, EPO can increase red blood cell production. Its detection in urine or blood depends on several factors, including the timing of testing and the method used.

Jepchirchir, 33, is among Kenya’s most accomplished distance runners. She won the women’s marathon at the Tokyo 2020 Olympic Games, which were held in 2021 because of the COVID-19 pandemic.

She later returned to the Japanese capital to claim the women’s marathon title at the World Athletics Championships in September 2025, adding another major achievement to her career.

Her success also extends to road racing. Jepchirchir broke the women’s half-marathon world record in 2017 and improved the record on two further occasions in 2020.

She has also secured victories at several of the world’s leading marathon events. These include the New York City Marathon in 2021, the Boston Marathon in 2022 and the London Marathon in 2024.

Her latest major victory came in Sydney on 30 August 2026, when she finished more than three minutes ahead of compatriot Irene Chepet Cheptai. The Sydney Marathon became the seventh race to join the prestigious World Marathon Majors series in 2025.

The positive sample was collected before the Sydney race while Jepchirchir was in Kenya. This means the test result relates to a sample taken before her victory, rather than one collected after the competition.

The Athletics Integrity Unit is responsible for protecting the integrity of athletics by overseeing anti-doping activities and investigating potential violations. A provisional suspension is a temporary measure that can prevent an athlete from competing while an anti-doping case proceeds.

Further developments will depend on the applicable anti-doping procedures and the handling of Jepchirchir’s case. The reported positive result does not, on its own, establish all the circumstances surrounding the finding or the final outcome.

The case represents a significant development involving a runner whose career includes Olympic, world championship and major marathon victories. It also places renewed attention on anti-doping enforcement in elite distance running, where athletes are subject to testing designed to protect fair competition.

Jepchirchir’s provisional suspension follows the reported positive EPO finding from her pre-race sample. The final outcome of the case will depend on the relevant proceedings and any subsequent decision by the responsible authorities.