Premier Gladys Berejiklian says the drug-related death of a 19-year-old woman at a Parramatta music festival on Saturday night "tears me to shreds", doubling down on her opposition to pill testing being introduced at large-scale music events.

The comments come less than 24 hours after the 19-year-old Central Coast woman died in hospital with her family around her after consuming a suspected deadly dose of pills at the FOMO music festival in Parramatta.

Fomo music festival, Parramatta.

Ms Berejiklian said she could not imagine what the young woman’s family and friends were going through.

“Every time a young person’s life is lost to drugs in this way just tears me to shreds,” she said.