RETRO drugs such as LSD and magic mushrooms are making a dangerous comeback, according to drug experts who warn recreational use of hallucinogenic drugs is on the rise.

School students in particular are at risk from the revival of the '60s substances with LSD at as little as $10 and mushrooms growing in backyards.

Sixty-four per cent of users surveyed had used LSD and three in four males aged over 14 had used mushrooms.

National Drugs and Alcohol Research Centre spokesman Paul Dillon said use of LSD and mushrooms was rising.

"They have been rising in the past couple of years and people are using it different ways, for example soaking sugar cubes in LSD. That drug also attracts a younger group because it is a very cheap drug," he said.

The latest NDARC report showed LSD was one of the most popular drugs used by regular ecstasy users in the past six months, with 32 per cent of users taking the drug, second only to cocaine which was 41 per cent.

The report profiled almost 1000 regular ecstasy users across Australia and found most had used LSD at age 18 with 64 per cent having used it. The rise in the use of magic mushrooms could be traced to users mistakenly believing they were safe because they grew naturally.

"When we give anti-drugs messages like 'it's chemical, you don't know what they put into it' sometimes you have a backlash with users," Mr Dillon said.

"Drugs users think, 'Well chemicals are bad for me so I'll use something natural,' but we know that natural does not necessarily mean safer. Sometimes it can be far more potent."

Flashbacks associated with LSD and magic mushrooms can be dangerous or even fatal, with the drugs often triggering a lifelong problem. A number of deaths have been associated with users picking the wrong strain of mushroom.