Pressure for pill testing is mounting after yet another music festival death -- the fifth in four months

The family of a 19-year-old girl who died of a suspected drug overdose over the weekend is pleading for pill testing at festivals in New South Wales.

Central Coast teenager Alex Ross-King died after taking a suspected dose of pills at the FOMO festival, an over-18s concert in Parramatta on Saturday.

The family is asking NSW Premer Gladys Berejiklian to show "strong leadership" and introduce pill testing in the wake of Ross-King's death.

"Premier, please: can we have this pill testing done. It's such a small thing to do, it's not hard. Let's try and get it out there," the teen's grandmother Denise Doig said on Network Ten last night.

"If it saves one life; one life is a life. And these are children."

Ross-King is the fifth person to die at a music festival in Australia in four months.

Most recently, Brisbane man Josh Tam, 22, died after taking a substance at the Lost Paradise festival on the Central Coast on December 29.

Callum Brosnan, 19, died at the Knockout Games of Destiny festival in early December.

And Joseph Pham, 23, and Diana Nguyen, 21, died at Defqon 1 music festival in September last year.

Berejiklian says it "tears me to shreds” when she hears of young people dying in such a way and wants to look for every opportunity to reduce deaths from drugs, but worries that "something like pill testing could have the opposite effect”.

"In the absence of evidence, we need to keep sending out the strongest message: that taking these illicit drugs kills lives, kills loved ones, and we ask young people not to do it," she says.

A protest calling for the introduction of pill testing in NSW is set to be staged in front of Sydney Town Hall on January 19.