Gwyneth takes my hand in hers, brings it to her mouth and sucks on my pinky. "I can't taste it," maybe she says. Her voice is almost too slurred for me to understand. I ease my finger from her mouth after she runs her tongue over it; it comes back sticky with dry saliva.

Before I pull my hand away she grips my wrist with one shaky hand and with her other fastiduously seperates my ring and middle-finger. Her eyes narrow as she inspects the powder that's not their, then brings them together and rubs the tips of both against her lips. Her charcole lipstick smears my nails.

Is her voice slurred because she's drunk?

You need to do a spell check ("charcole"). You also need to read for spelling ("not there" vs. "not their").

How does she inspect a powder that's not there?

It doesn't work for me; I'm not hooked, and I'm thrown out by lines like "sticky with dry saliva", which just doesn't work at all, and the "...then brings them together" which (although it clearly means the narrator's fingers) reads like it's referring to her eyes.

However, there are some crits:

As has already been pointed out the word 'maybe' doesn't really work. You could maybe say. 'She mumbles something that sounds like, "I can taste it"...' or just cut the word 'maybe.' Depends how uncertain you want that sentence to be. If that really IS what she says, then I'm not sure you need to make it sound uncertain.

The "sticky with dry saliva" image is a tricky one. I got it the third time I read it but I shouldn't have had to read it 3 times to get it. It's a nice image though you should try and save it. I just think you need to give a little bit more information "Hey mouth is dry and clumps of saliva have formed at the corners of her mouth. When I pull my finger away it's sticky with dry strings of it" something like that (probably less graphic).

As for the whole "what the hell is going on" thing. If you don't have some explanation/exposition coming in the next paragraph or two I think you risk losing a bunch of people. Maybe give 1 or 2 more hints here. Give the powder a name e.g. "Coke" or, if it's something made up, give it a made up name. Make the drug thing (which again I'm assuming it is) more obvious. You're making the reader work very hard at the moment and the more the reader's working the less likely they are to get carried away by the story itself.