Jockey Levi Williams was banned for six months after he tested positive for cocaine and cannabis.
Williams has sought help in stopping drug use since the failed test at Wolverhampton on January 29, a disciplinary hearing was told.
He was given leave of absence during the Covid-19 pandemic and admitted to making a “stupid mistake”.
The rider offered to use his experiences to teach young riders the dangers of drug abuse.
“He is very happy to help talk to the newcomers about the real harm and occupational risks that drug use poses,” said Rory MacNeice, Williams representative.
“He has changed his living arrangements and is now in a more supportive environment.
“He realizes that his experience may help others make the same mistakes.”
British horse racing started last month Pilot for two months of using saliva tests to screen riders for cocaine and other prohibited substances.
There has been an increase in the number of positive urine samples in recent years, with six in 2019 and five in 2020, after no more than three positive urine samples in one year between 2012 and 2018.
The knights were Adrian McCarthy and Finley March Both imposed a six-month ban In March for cocaine use.
In April, jockey Benoit de la Sayette failed a drug test days after denying he had used cocaine.
Andrew Howell, of the British Horseracing Authority (BHA), said Williams had admitted breaking the rules.
The rider said he only smoked weed once or twice, including while at a party with friends around the New Year. “I didn’t really think, I was just stupid,” he said.
He also used cocaine when he wasn’t riding, but realized it was a “bad idea” and has since sought help from the Sporting Chance Charity and Professional Riders Association.
“This is an important and encouraging step from the BHA’s perspective,” Howell said.
“You have made a real effort to rehabilitate yourself and put your knowledge to good use to help others,” said Brian Parker, chair of the disciplinary committee.
Williams will be eligible to reapply for his license starting August 4 after serving a temporary suspension since February 5.
The latest Lethal Talent winner came for Newmarket coach Jane Chapple-Hyam, in Lingfield on December 31, 2020.