"I like that we can have a chat. It gives us an occasion to see people, and get a glow on," said Ms Boscheinen, 19.

However, if Christian Democratic MLC Fred Nile gets his way, Ms Boscheinen and her friends will no longer be glowing.

He is calling for the drinking age to be raised to 21, to combat the "health problems, social problems, and violence associated with alcohol".

"The effect of alcohol on the developing brain of adolescents, probably up to 24 years of age, is quite dramatic, quite serious," he said.

In a paper for the Medical Journal of Australia last year, researchers argued there was mounting evidence to suggest that even at age 18, drinking alcohol could be harmful.

"When everyone drinks their body and their brain change as a response. When you're young that happens very rapidly and you quickly develop a tolerance," said John Toumbourou of Deakin University's School of Psychology.

"The problem is when you have a drinking age of 18 people often starting to drink at 16 or 17, and that's the reason why there's the view that, if you raise it to 21, you're getting past that secondary school age period," said Dr Toumbourou.

Reverend Nile, who may hold the balance of power in NSW's upper house, said critics need only look to the medical research that supports the idea.

"The medical profession have come out separate from me, they're not campaigning for me. It's come at an ideal time when I'm raising this legislation."

He said the key to successfully implementing a change to the drinking age would be education.

"With all my other controversial legislation, banning cigarette advertising and smoking in public places, they all had a five-year education program. It's important to carry people with you, and in this case it's vital that we carry young people with us."

Mr Nile has offered only conditional support for the government's cornerstone policy to privatise part of the state's electricity "poles and wires", but he rejected any speculation that his crossbench support was tied to his call to raise the drinking age.

Ms Boscheinen and Mr Borg, both 19, said it would be "belittling and unfair" if their right to drink alcohol was removed.

The group said their drinking pattern increased in the months of celebration after finishing school, but since starting university it had dropped to a big night out once a week and some quiet drinks once or twice a week.

"I love going out to a small bar and having a few drinks. It's unfair that they would stop me doing that," said Ms Boscheinen, while Mr Borg said the pub was the perfect place to catch up with mates.

"It's common ground. It's relaxed, everyone is having a bit of a laugh," he said.

While they would be affected by default, Mr Nile said the proposed legislation is not targeting responsible young people having a few quiet drinks, but those engaging in binge drinking.

"The pattern of binge drinking, which is so common, is actually damaging your brain cells," said Professor Ian Hickie, Brain & Mind Research Institute.

"If you want to end up with the smartest, most capable, most socially adjusted kid in terms of brain development you will minimise the exposure to alcohol during those early periods."

Ms Boscheinen said the idea was unrealistic, as coming of age at 18 is embedded in Australian culture.

"Either way, people are still going to drink, but it would just be illegal. I feel like it would put more people back on the streets drinking, rather than in a bar or pub," she said.

"I think it would completely contradict the aims of the lockout laws."