Kieren Fallon has failed in his bid to have his worldwide racing ban reduced by French racing authorities.
Fallon is keen to return to race riding after his ban finishes
The six-time champion jockey tested positive for a banned substance at Deauville last August and was given an 18-month suspension in January.
But the 42-year-old Irishman had appealed against the severity of the punishment.
Earlier this week he confirmed he was to link up with former boss Sir Michael Stoute again as a work rider.
Fallon's French agent Herve Naggar said: "The ban has been confirmed after appeal. It is a worldwide ban that finishes on 8 August, 2009."
The Irishman still remains keen to return to riding when the ban comes to an end.
"It would have made a big difference to be able to return to race-riding at the beginning of the season next year, rather than midway through it. But at least the uncertainty is over," he told the Independent newspaper.
"There have been many jockeys come back from far worse situations than this. I really do believe that I can come back a stronger person."