When mother of two Jackie Hays began taking a weight loss drug, her friends noticed she started to act strangely.
Her behaviour seemed to change. She looked as though she was "off the planet".
Four months after being prescribed the drug Duromine, the support staff member at a Hunter Valley school in NSW became infatuated with a 15-year-old student and decided she wanted to have sex with him, sending him numerous explicit text messages.
Legal Aid defence lawyer Gillian Jewison told Newcastle Local Court on Thursday Ms Hays, 51, who pleaded guilty to grooming the student for sex between April 2015 and June 2016, blamed the drug and her borderline personality disorder for her predatory behaviour.
Ms Hays claimed the drug dramatically increased her sex drive and impaired her judgment.
Ms Jewison acknowledged there was no medical evidence linking the drug to Ms Hays' behaviour but said anecdotal evidence showed her behaviour changed after taking the drug.
The defence lawyer submitted a psychological report confirming Ms Hays had been diagnosed with a borderline personality disorder, anxiety and depression and applied to have the grooming charge dropped.
Magistrate Robert Stone accepted Ms Hays did suffer from mental health issues but found the case against her was too serious to dismiss.
Mr Stone said Ms Hays had detailed "lewd, descriptive acts" in a series of explicit text messages sent to the boy suggesting she wanted to have sex and she would either be jailed or receive a suspended jail term when sentenced next Wednesday.
"In general terms, the community expects better from people who work at schools with children," Mr Stone said.
"She knew it was inappropriate. She knew it was illegal to have sex with the boy."
The magistrate said sentencing Ms Hays would be a difficult exercise because specific details of the text messages were unavailable given the boy's phone had been lost before Ms Hays' arrest.
Prosecutor Stuart Ogilvy, in opposing the application to have the charge dismissed, said there was nothing to suggest the drug had affected Ms Hays' mood, caused her anxiety or changed her sex drive.
Mr Ogilvy said when Ms Hays was interviewed by detectives, she described the text messages as "filth".
Ms Hays admitted she was willing to have sex with the boy but claimed she wanted to wait until he turned 16.
Mr Ogilvy said Ms Hays came to know the boy and his family through the school and she had abused their trust when trying to arrange to have sex with the teenager.
Ms Hays was initially charged in mid-2017 with five offences alleging she had been sending explicit text messages and phoning two students but four of the charges were later dropped after she agreed to plead guilty to the one count of grooming a child for unlawful sexual activity.
Police set up Strike force Minnamorra before Ms Hays' arrest after being alerted by the school to the grooming allegations.