Background: There is an increasing interest in herbal products as a self-medication method in recent years. Some plant extracts either turn into drugs over time or are consumed directly without treatment. One of these plants is Nerium oleander L., which is a potentially lethal plant, since it has cardiac glycosides. However, numerous researches of its extracts have been performed against cancer cell lines in recent literature. This contradiction leads to misinterpretation and induces the prevalence of intoxication or fatal cases.