Elemenes are a group of closely related natural chemical compounds found in a variety of plants. The elemenes, which include α-, β-, γ-, and δ-elemene, are structural isomers of each other and are classified as sesquiterpenes. The elemenes contribute to the floral aromas of some plants, and are used as pheromones by some insects.
β-Elemene has attracted scientific interest because of its prevalence in a variety of medicinal plants. Experiments performed in vitro show that β-elemene has anti-proliferative effects toward some cancer cell types, indicating the possibility of its use in chemotherapy. Small scale, low quality clinical trials in China have been conducted in which benefits for cancer treatment have been reported. However, the Memorial Sloan–Kettering Cancer Center states that "human trials conducted so far are of poor quality". A Cochrane Review of the available literature concluded that "there is no evidence from randomised controlled trials to confirm or refute the effectiveness of elemene as a treatment for lung cancer".