The former Tokyo Marathon champion tested positive for methylprednisolone, but a falsified medical prescription and misleading statements to investigators turned a doping violation into a six-year suspension.
Ethiopian marathon star Ruti Aga has been banned for six years, but the most damaging part of her case was not simply the presence of a prohibited substance in her system. It was what happened when anti-doping investigators began asking questions.
The 32-year-old, who won the prestigious Tokyo Marathon in 2019, tested positive for methylprednisolone following her victory at the Meishan Renshou Half Marathon in China on March 15, 2026.
The Athletics Integrity Unit (AIU) imposed a two-year sanction for the substance violation and an additional four years for tampering with the investigation.
The six-year ban took effect on September 10, 2026, the date of her provisional suspension.
The Medical Explanation That Fell Apart
Aga sought to explain the positive test by claiming she had received treatment for a knee injury.
She submitted medical documentation to support that explanation. But investigators found serious irregularities.
The prescription referred to a clinic that did not exist. The supposed prescribing doctor was reportedly a family member who was not registered to practise medicine. A clinic associated with an old prescription pad denied any connection with the document.
The AIU concluded that the medical evidence had been falsified. It also found that Aga had misled officials during the investigation.
What might have remained a two-year doping sanction consequently became a six-year exclusion from competition.
For an athlete who had established herself among the world’s leading marathon runners, the consequences are potentially career-defining.
What Is Methylprednisolone?
Methylprednisolone is a synthetic corticosteroid used to treat inflammation, swelling, allergic reactions and certain painful medical conditions.
It is not an anabolic steroid used for building muscle. Instead, its anti-inflammatory properties can reduce pain and discomfort, potentially helping athletes train or compete despite injuries.
The medication is available in different formulations, including methylprednisolone acetate, commonly used in longer-acting injections, and methylprednisolone sodium succinate, used in injectable preparations.
Importantly, the publicly reported findings do not establish which specific formulation Aga used.
Under the World Anti-Doping Agency’s (WADA) 2026 Prohibited List, methylprednisolone belongs to the S9 Glucocorticoids category.
Glucocorticoids are prohibited during competition when administered orally, by injection or rectally, unless the athlete has appropriate therapeutic authorisation. Other routes, including certain topical and inhaled applications, are generally permitted under specified conditions.
How Long Does the Drug Remain in the Body?
WADA recommends different washout periods depending on how methylprednisolone is administered.
For oral administration, the standard washout period is three days. Intramuscular injections require five days, while most local injections carry a three-day guideline.
These periods are intended to reduce the possibility of a positive test. They are not guarantees that a substance will become undetectable.
Sustained-release formulations may remain detectable beyond the recommended period.
Athletes requiring genuine medical treatment must maintain accurate medical records and, where necessary, obtain a Therapeutic Use Exemption (TUE).
A Warning Beyond One Athlete
Aga’s case illustrates how anti-doping violations can extend far beyond a positive laboratory result.
Under the World Athletics Anti-Doping Rules, the presence or use of a prohibited substance and tampering with the investigation are separate violations, carrying separate consequences.
The AIU’s six-year sanction reflects that distinction: two years for the drug offence and four for interfering with the process.
For athletes, coaches and medical support teams, the implications are significant. A legitimate medical condition does not automatically excuse the use of a prohibited substance. Equally, attempting to manufacture medical evidence can carry consequences even more severe than the original violation.
Aga’s case has become a stark reminder that anti-doping enforcement is not limited to detecting prohibited drugs. It also depends on the honesty of the explanations and evidence provided after a positive test.
For the former Tokyo Marathon champion, that distinction has proved devastating.