Kenyan marathon champion Peres Jepchirchir has received a provisional suspension after testing positive for a banned performance-enhancing substance.
The Athletics Integrity Unit (AIU) announced the decision on Friday, October 23.
According to the AIU, a sample collected from Jepchirchir in Kenya tested positive for erythropoietin (EPO), a substance that can improve athletic endurance.
The sample was collected before her victory at the Sydney Marathon in August.
The suspension has raised questions about the future of one of Kenya’s most successful distance runners.
However, the case remains under review, and the provisional suspension does not represent a final ruling.
Peres Jepchirchir tests positive for EPO
The AIU said an out-of-competition sample returned an adverse analytical finding for EPO.
EPO is a hormone that stimulates the production of red blood cells.
Athletes can misuse the substance to increase the amount of oxygen their blood carries. As a result, it can improve endurance during long-distance events.
For this reason, anti-doping regulations prohibit its use without an applicable medical exemption.
The AIU has provisionally suspended Jepchirchir while the case proceeds through the relevant disciplinary process.
A provisional suspension temporarily prevents an athlete from competing. However, it does not automatically establish a final anti-doping violation.
The 33-year-old runner is entitled to the applicable procedures before authorities reach a final decision.
Sydney Marathon organisers respond
Jepchirchir won the women’s Sydney Marathon on August 30, 2026.
She finished the race in two hours, 18 minutes and 31 seconds.
Her performance placed her more than three minutes ahead of fellow Kenyan runner Irine Cheptai, who finished second.
Following the AIU announcement, Sydney Marathon organisers expressed disappointment.
However, they also stressed that Jepchirchir has the right to due process.
The organisers said they would avoid further comments until the disciplinary proceedings conclude.
They also reaffirmed their commitment to protecting fair competition.
In recent years, major marathon organisers have increased their investment in out-of-competition testing.
These efforts aim to detect prohibited substances and strengthen confidence in race results.
Agent reacts to doping allegations
Jepchirchir’s agent, Gianni Demadonna, also responded to the announcement.
In a statement reported by Reuters, Demadonna expressed disappointment over the positive test.
He said athletes who use performance-enhancing drugs should face disqualification.
However, authorities have not yet announced a final decision in Jepchirchir’s case.
The runner’s provisional suspension remains in place while the disciplinary process continues.
Jepchirchir’s major marathon achievements
Peres Jepchirchir is among Kenya’s most decorated female marathon runners.
She won Olympic gold in the women’s marathon at the Tokyo Games in 2021.
That victory established her as one of the leading distance runners of her generation.
She also won the New York City Marathon in 2021 and the Boston Marathon in 2022.
In 2024, Jepchirchir claimed another major victory at the London Marathon.
Her success continued in August 2026 when she won the Sydney Marathon.
In addition, she previously held a world record in the women’s half-marathon.
Her achievements have made her a prominent figure in international athletics.
Kenya faces continued doping concerns
The latest case comes amid ongoing concerns about doping in Kenyan distance running.
Kenya has produced many of the world’s leading marathon athletes. However, several high-profile runners have also faced anti-doping sanctions.
In 2025, women’s marathon world record holder Ruth Chepngetich received a three-year ban.
She admitted anti-doping rule violations involving hydrochlorothiazide, a prohibited diuretic.
Nevertheless, her marathon world record remained valid because she achieved it before the positive test.
The Jepchirchir case now places another prominent Kenyan athlete under scrutiny.
For now, the AIU has not announced a final sanction.
The outcome will depend on the disciplinary process and any evidence presented during the proceedings.