I don't know about the borderline-part, but this movie nails it when it comes to opiate addiction.
The main character shows exactly what torments the addictee goes through, extreme selfishness during withdrawals, lack of money, violence, crime, and with a complete disregard of the consequences, as long as acquiring the objective, which is, of course, drugs.
The main supporting character is perhaps even better. A drug user herself, she is not addicted and mostly able to keep her head cold, and her affection for the more compromised main character is also realistic, although many would have quit before her - there really are some ones that go several extra miles for their friend.
There is explicit nudity, yes, but that is also realistic. The actors are only nude in situations where their characters realistically would be nude. Nothing is exaggerated for shock value.
Can recommend for all drug users currently struggling and for relatives of same. Of course it has its flaws with such a small budget, but it is more than worth it.