Ainslie, 26, tested positive for GW1516 sulfone following an in-competition urine sample he provided at the USA Cycling Elite & Jr. Track National Championships on August 3, 2017.
The performance-enhancing hormone and metabolic modulator is prohibited at all times under the USADA, the World Anti-Doping Code and the World Anti-Doping Agency’s list of prohibited substances.
Also known as GW501516, it is an experimental drug that was found to cause serious toxicities during pre-clinical studies, USADA said.
In 2013, WADA issued an alert warning that GW1516, which is not approved by the FDA, is being sold illegally on the black market and obtained by athletes.
Based on Ainslie’s admission of guilt, USADA said, his sanction was reduced by six months at the discretion of USADA and WADA.
His 42-month period of ineligibility began Aug. 3, 2017, the date his positive sample was collected. USADA says he has been disqualified from all competitive results after that date, and has been stripped of any medals, points and prizes.
Ainslie with his younger brother, Rex, made custom cycling shoes under the Ainslie Bothers brand.
He joined the San Diego Bicycle Club in 2016 as a guest rider for a pro 1/2 team, “mainly to race with his friends on SDBC,” said a club report.
“With the help of his team, he won an early season criterium in San Diego,” the club said. “Later this year, Roger finished second overall in the State Criterium Championship and in the process became the Cat 2 State Criterium Champion.”
In July 2017, Ainslie teamed with Stephen Hall of Australia to win the 9th Annual Mike Walter Madison, a 100-lap race in Trexlertown, Pennsylvania.
In June 2016, Ainslie took part in the 22nd annual Tour de Donuts in conjunction with the UCSD Triathlon team and the Campus Bike and Skate Shop.
“The standing record of 18 donuts held by Ian MacNeill was smashed by Roger Ainslie, who devoured an incredible 21 donuts, and claimed the title of ‘Gluttonous Champion,’” the UCSD club site said.
— Toni McAllister contributed to this report.