The movie has nice cinematography and good acting, but it's an all-girl cast. It's about a few heroin addict girls trying to get clean in a rehab center and they fight each other like prisoners would in prison. That's all the movie is all about. There are no scares, no thrills, nothing. Just because people die in a movie, it doesn't get to be called a horror movie. I think a new sub-genre should be created for movies like this so horror movie fans will know they should avoid them, something like: crime, murder. This is no Scream. It's lame and boring with a generic plot. Actually, I can barely call it a plot, because it's too basic. Close your eyes and imagine this: two girls are fighting a normal fight with fists in a well-lit corridor, one of them picks up a shard of glass and stabs the other, and the other girl just falls to the ground and dies. There's no gore either.
Now, slowly open your eyes. Did that scare you? Did you find that thrilling or interesting in any way? That's what you're going to get by watching this movie. If you found the picture I described interesting, scary or thrilling even a bit, please go ahead and watch this movie. Otherwise, save yourself an hour and thirty minutes of your life and watch something better. The gore you see in the trailer is what one of the girl's sees in her head a few times during the movie. It's got nothing to do with the main story-line, and it's merely there as an excuse to make an interesting trailer in order to deceive the audience.
And no, please don't thank me. It is my duty to warn you. If I can save even one person's time, I will have served a purpose in this world.