The condition of several people taken to hospital in critical conditions from Australia Day music festivals in Sydney has improved.

Six young men aged under 25 were taken from the Hardcore Till I Die festival at Sydney Olympic Park on Saturday in critical or serious conditions.

Read More Police, medical personnel out in force for music festivals after drug deaths

Meanwhile, eight people age 19 to 67 left Electric Gardens Festival in Centennial Park in an ambulance.

But NSW Health on Sunday said all 14 were either in stable conditions or had been discharged from hospital.

Drugs were thought to be a factor in 10 of the 14 cases.

"NSW Health would like to acknowledge the hard work and dedication of the staff and volunteers at the Hardcore Till I Die and Electric Gardens festivals, ensuring the safety of the many thousands of attendees," a NSW Health spokeswoman said.

"The additional critical care staff contributed significantly to the positive outcomes seen overnight."

Seven people, including a 19-year-old South Australian woman, were charged with drug supply at the Till I Die festival.

One Electric Gardens attendee was picked up for the same alleged offence.

Police say at least 75 people were caught in total for drug-related offences, with 68 issued criminal infringement notices and others given cautions.

One Electric Gardens attendee was picked up for the same alleged offence.

Police say at least 75 people were caught in total for drug-related offences, with 68 issued criminal infringement notices and others given cautions.