It can also damage your brain and turn you into a psychopath, but what gets people hooked in the first place is a feeling far greater than the horizontal shuffle.

That's what a summit on methamphetamine, held in Melbourne's south-east on Thursday, was told by Kiwi ice expert and former drug detective Mike Sabin.

Mr Sabin told the Mount Waverley forum that methamphetamine releases 1250 units of dopamine - the brain's natural reward chemical - into the system.

That's six times more than sex, which drops 200 units, and three times more than cocaine, which releases 400 units. The average pat on the back at work releases a mere 100 units.

''The world has never known another drug that can reinforce such a major response,'' Mr Sabin said.

But it also erodes the brain's ability to naturally release dopamine, which is why heavy users say they can no longer feel happy without the drug.

''They take the drug to try to feel normal,'' Mr Sabin said.

Usually, he said, these users go on a three- to 15-day binge to maintain their high. They often go into a state called ''tweaking'', where they stay awake for days at a time.

''This is when you see the most irrational and dangerous behaviour,'' he said.

Mr Sabin told of a triple murder he responded to as a police officer in New Zealand, where a man had severed the heads of his two children and fatally stabbed a neighbour. ''He was completely delusional, completely psychotic.''

Mr Sabin, who gave evidence to the Victorian parliamentary inquiry into ice on Thursday night, said Victoria had a chance to lead the country's approach to methamphetamine by creating a cultural shift such as those related to smoking, drink-driving and skin cancer.

He called on authorities to strike a balance between reducing both supply and demand, coupled with treatment, instead of focusing on reducing the harm.

''Prevention first, intervention next, and if we don't intervene early enough, they get too far down the track … [coming] to treatment when their lives have collapsed,'' he said.

Inquiry chairman and Western Victoria MP Simon Ramsay, who also addressed the forum, said the findings would be tabled in Parliament in September.