I'd say
it turns aggressive twats into worse ones, cf. alcohol.

The idea that an otherwise totally sound person has been made into a total cunt by ANY substance is, from experience, utter bollocks. Boring cunts who like the sound of their own voices become worse etc.

It makes me quite quiet.
( Monty Boyce, My cheese game is strong, Mon 7 Dec 2009, 13:08, 3 replies, latest was 16 years ago)

It also turns normal people....
...into adverstising executives or some such loud-mouthed twattery.
(Tugnut Ex of this parish, Mon 7 Dec 2009, 13:10, Reply)

praise the lord!

( Vipros. clever got me this far, then tricky got me in, Mon 7 Dec 2009, 13:10, Reply)

are you saying I should shut up?

( Monty Boyce, My cheese game is strong, Mon 7 Dec 2009, 13:11, Reply)

no
but that it would be nicer if you did ;-)
( Vipros. clever got me this far, then tricky got me in, Mon 7 Dec 2009, 13:19, Reply)

fack orf you fackin wankah

( Monty Boyce, My cheese game is strong, Mon 7 Dec 2009, 13:22, Reply)

I'm terribly sorry
I don't understand Laaahndaaahn, innit
( Vipros. clever got me this far, then tricky got me in, Mon 7 Dec 2009, 13:23, Reply)

Roight you baaaaastard
Oi'll 'aaave you, Oi will!

Is that better?
( Monty Boyce, My cheese game is strong, Mon 7 Dec 2009, 13:24, Reply)

much
I appreciate it
( Vipros. clever got me this far, then tricky got me in, Mon 7 Dec 2009, 13:27, Reply)

that's a good point
alcohol does similar. alcohol + coke = fighting fuel, if you're a bit of a nasty bastard to start with, like a lot of people round my way.
(raymond "three griddle pans" luxury yacht lovin' the christmas action, Mon 7 Dec 2009, 13:30, Reply)

And one reason I try to avoid coke is that
I've got a big mouth to start with. After a couple of lines I hardly know what I'm saying, but keep saying it, loudly, however inappropriate it is, often pissing people off.
(raymond "three griddle pans" luxury yacht lovin' the christmas action, Mon 7 Dec 2009, 13:32, Reply)

I applaud your honesty and self-awareness.
Would that others shared your introspection.
( Monty Boyce, My cheese game is strong, Mon 7 Dec 2009, 13:34, Reply)