On-the-spot fines for drug possession at music festivals will come into effect this weekend but experts warn that the changed legislation will do little to deter young people from taking drugs and will not stop festival deaths.

The move away from having offenders attend court to instead instant fines for drug possession was recommended by an expert panel commissioned by Premier Gladys Berejiklian in the wake of two fatalities at the Defqon.1 festival in September.

Joseph Pham and Diana Nguyen both died of suspected overdoses at Defqon.1 music festival in Sydney.

Since then, three more young people have died after taking drugs at music festivals in NSW and one man has died in Victoria.

"Advice was received from stakeholders about festival attendees’ behaviour in relation to police enforcement methods, including anecdotes of people hurriedly consuming drugs to avoid detection. Provision of on-the-spot fines for possession of prohibited drugs at music festivals provides for a harm reduction approach," read the panel's report.