A failed appeal against a two-year sentence means that former cycling medical adviser Bernard Sainz will have to spend a year in jail.
The former soigneur was implicated in the 1998 Tour de France Festina scandal, and in 2002, Sainz was stopped at a traffic control and a haul of illegal substances was found.
A subsequent search of cyclist Frank Vandenbroucke's house revealed EPO, morphine and clenbuterole, which helps building muscle mass. Vandenbroucke died in October last year of a pulmonary embolism.
On Thursday, a Paris court rejected Sainz's appeal against his sentence after being convicted of "incitement to doping" and illegally practising medicine in 1998 and 1999.
Sainz was sentenced to two years in prison, including one year suspended.
Sainz, 66, was put under investigation in May 1999, accused of providing testosterone and other performance-enhancers to cyclists. He has repeatedly denied the charges, arguing that he was providing only homeopathic therapy.
Sainz, nicknamed 'Dr Mabuse', now says he will go to the European Court for Human Rights in Strasbourg. In 2000 he wrote a book called "The stunning revelations of Dr Mabuse." He defended himself and denied that he was responsible for Cyrille Guimard's abandoning of the 1972 Tour de France. Guimard had to stop due to knee problems and many blamed Sainz and his 'homeopathic' methods.