Jockey Ryan Maloney has been suspended for four months after pleading guilty to providing a positive urine sample to a banned stimulant.

Maloney hasn't ridden since self-reporting and standing down after being randomly selected to provide a urine sample at Caulfield on March 31.

At an inquiry on race day, Maloney told Racing Victoria stewards he had taken the appetite suppressant Duromine, however the report from Racing Analytical Services Limited indicated it contained an unnamed banned stimulant.

On Tuesday Maloney was suspended for four months, back-dated to March 31, and he can return on August 1.

Stewards will allow Maloney to return to riding trackwork once he provides a sample clear of any banned substance and an accompanying medical certificate.

During the hearing stewards considered inaccuracies in Maloney's evidence at Caulfield before deciding on Tuesday not to take any further action.

The suspension comes at a bad time for Maloney who sits within the top 20 on the Victorian jockeys' premiership with 53 winners at a strike-rate of 16 per cent.

The suspension has also cost him the ride on exciting three-year-old Nature Strip in the VOBIS Gold Dash at Caulfield on Saturday.

Maloney has ridden the gelding in four of his five starts, for three wins.

Craig Williams takes over on Saturday.