Jockey Michelle Payne will miss race riding for four weeks after pleading guilty to taking a banned appetite suppressant.

Melbourne Cup-winning jockey Michelle Payne is sorry and embarrassed over the mistake that led to her four-week suspension for taking a banned appetite suppressant.

Payne says she should have sought more information after her doctor prescribed Phentermine to help deal with gastrointestinal problems connected to injuries she sustained in a serious race fall.

The first female jockey to win the Melbourne Cup says she accepts full responsibility and regrets she did not handle the situation better.

"The onus is 100 per cent with me as a rider to know what I am taking and the rules around it regardless of whether it has been prescribed to me or not," Payne told reporters on Thursday.

"I wasn't thorough and that is completely my fault."

Payne admitted taking the banned substance and said she was sorry and embarrassed.

"If I had known it would be still in my system and I would be riding with a banned substance in my system, I wouldn't have been riding," she told a Racing Victoria stewards' inquiry.

Payne's barrister Michael Rivette said the 31-year-old blamed no one but herself for the mistake.

"She's extremely embarrassed and has shown genuine remorse for her mistake," he said.

Inquiry chair Robert Cram said Payne admitted she knew Phentermine was a banned substance under the racing rules.

Cram said stewards took into account her guilty plea, remorse, good record and medical circumstances.

"However, notwithstanding those factors it is our view that you didn't comply with your fundamental obligation to seek advice before taking the substance Phentermine," he said.

Cram said Payne could have applied to take certain medication on medical grounds but failed to do so.

Payne has been banned from riding in races for four weeks, until July 21.

She was stood down on June 23, after the positive test from a urine sample taken at the Swan Hill Cup meeting on June 11.

Payne said she was in a mad rush and "didn't give it another thought" when she filled out a form on race day and did not declare the substance.

Payne underwent abdominal surgery after her fall in May last year.

Her doctors now plan to trial new medication to reduce her gastrointestinal symptoms.

"Going forward I am very much looking forward to finding a solution and working in with my surgeon," Payne said.

"I look forward to working hard and being in great shape upon my return to racing."

Payne rode at Royal Ascot last week and has been invited to compete in the Shergar Cup international jockeys' challenge at Ascot on August 12.

Australian Jockeys Association chair Des O'Keeffe said the four-week suspension seemed to be an appropriate and fair penalty, adding it would not tarnish Payne's reputation.

"She's made a mistake. It's as simple as that," he said.

O'Keeffe says the buck stops with jockeys to know what they can and cannot take.