Xanthines, such as caffeine, are closely related alkaloids that occur in plants throughout the world. Xanthines are closely related both chemically and in their actions on the human body. The spectrum of xanthine usage ranges from very serious abuse to abstention or the occasional consumption of chocolate and cocoa products, coffee, cola drinks, or tea. Between these extremes are found all combinations of xanthine consumers, with most people in the world using these drugs every day of their adult lives, and the majority possibly abusing them. The purpose of this article is to identify what the xanthines are and where they are found, how they act on our bodies, why people use them, and what our knowledge of them says about the Word of Wisdom.