Love Medicine, by Louise Erdrich, is actually a collection of short stories which deal with the lives of two families (Kashpaws and Lamartines) of the Chippewa culture, and how each family, in the several generations described, do their best not only to survive, but to learn how to deal with the world, and find their place within that world.
I believe that the concept of "love medicine" is the hope that there is something that will heal the wounds of the characters in these fourteen stories. And although "love medicine" is referred to in one story about Lipsha Morrissey (who is said to have a special mystical gift, handed down through the ages by his ancestors), it would seem that this is a broad concept that is woven throughout all the stories in this collection.
The stories do not only speak of the relationships between the characters (of the two families in the book), but take on social aspects of the Native American culture that fragment the individual and the society, for which healing is necessary, if it can be found. These social aspects include the lures of the white man's world—drunkenness, government control, the harshness of the prison system, and organized religion.