Philip Fenton has been disqualified from holding a trainer's licence for three years following an Irish Turf Club hearing.
Fenton was called before officials after being found guilty of possessing anabolic steroids and other banned substances at a district court hearing last month.
A cardboard box packed with 25 bottles and containers of animal remedies was found hidden in the horse spa in his yard in County Tipperary during a search by officials from the Department of Agriculture in January 2012.
Among them was one kilo of the anabolic steroid Nitrotain in a paste form in a black tub - enough for 250 doses - and a 20ml bottle of a second performance-enhancing drug Ilium Stanabolic.
Fenton was fined 6,000 euro as well as being ordered to pay a further 4,200 euro in costs following the case.
The Cheltenham Festival-winning trainer did not give evidence in the one-day hearing in Carrick-on-Suir District Court and refused to explain afterwards why he had the steroids in his yard.
Fenton's disqualification period from training horses will begin from midnight on Friday, November 28.
On March 1 next year he will be disqualified entirely from any horseracing environment.
Fenton's solicitor pleaded for a financial punishment, rather than disqualification, but a Turf Club panel felt the severity of the offence was of sufficient gravity to hand out a three-year suspension.
Head of the panel Tony Hunt said Fenton would still have the right to appeal.
The 49-year-old trainer enjoyed great success with Dunguib, who won the 2009 Champion Bumper at Cheltenham, and Last Instalment, but those two horses have since been retired.
The Tullow Tank was another flag-bearer for the yard, but he has already been transferred from Fenton's stables by owner Barry Connell.
Powerful owners Gigginstown House Stud also removed the three horses they had in training with Fenton, including the Grade Two-winning Real Steel.
Fenton had a runner at Gowran on Saturday when Ange D'Or Javilex finished third in a two-mile novice hurdle.