Parents need to know that Chemical Hearts depicts teenagers dealing with grief, trauma, heartbreak, sexual awakening, drugs, alcohol, and the death, by accident or suicide, of peers. The general tone of the film is dark. The high school seniors conclude that the teen years are painful as they rip you away from the safety of childhood, while adults are just scarred children who made it out. The two main characters, Henry and Grace, both learn that heartbreak feels the same as physical pain. They flirt, date, slow-dance, and kiss, then eventually have sex. Grace is more experienced than Henry, and she asks if he has a condom then puts it on him. Two girls kiss after admitting how much they like each other, even though one of them expresses confusion and says she's "hooked up" with a lot of other girls. At a party, Henry smokes "kush" from a pipe and says he's "trashed." Other teens drink out of red plastic cups. Grace says she used to be a "beer pong champion" and another student mentions acid. Language includes "bulls--t," "s--t," "f--k," "sucks," "dope," "God."