I watched this film on a recommendation for its gritty portrayal of a cocaine addict and the people met during the descent. As real a depiction of actual a. drug usage b. user habits c. desperate, unimaginable situations that HAPPEN and d. the mental pattern of someone who recognizes what they gave up to have it.
As is mentioned in most reviews, some scenes are heart-wrenching, some are of graphic drug use (as graphic as drug use gets), a lot are both. This is a sad movie and it's filled with sad, pathetic characters. All are acted to PERFECTION, including most of the bit parts. The lead is astonishingly good at being a cokehead and displays constantly the little things that change about one's speech and thoughts as they lose touch with reality. If you've known a cokehead, you will watch this movie and say "a-ha, I remember why I hated that guy".
With a tragic antihero on camera in every scene of the movie, this is a very personal affair and shows everything he might do in a day (including using the toilet, random, meaningless encounters, etc.). I've yet to see a movie that spent this few words expressing this much personality (or ruins of one, really).
I thought the ending was particularly good and fit the story well as far as it parallels real life stories, as what you see in the last few scenes is what you're expected to believe is the main character's final stage in life (and presumably, not a particularly long one, depending entirely on what you think this man will do when he wakes the following day, which on its own is reason enough to watch this movie).
While someone else mentioned recovering users might have trouble watching this film, it is NOT because of the graphic drug use, it IS because they will be steadily reminded of the consequences of their own past use, which sucks, but is about as good a booster shot for not-ever-doing-drugs-againism as one could ask for. Enjoy...