The genus Cordyceps, which comprises a group of insect parasitizing fungi, is regarded as an important component of traditional Chinese medicines and extensively investigated for its pharmacological actions. A wide range of natural products such as proteins, cyclic peptides, polyamines, nucleosides, polysaccharides, and sterols have been reported to be present in Cordyceps. Nucleosides cordycepin and its analogs, polysaccharides, and sterols are the major bioactive compounds in Cordyceps, which are associated with multiple pharmacological effects, such as anticancer, immunomodulatory, aphrodisiac, and hypoglycemic properties. Most of the health benefits of Cordyceps were reported from in vitro and in vivo animal experiments and a few clinical trials. Cordyceps is considered as generally safe for human use and has a potential to be used as adjunctive therapy in diseases such as diabetes, cancer, and renal failure; however, no well-defined toxicological studies have been published. Because of significant structural and compositional variation among bioactive compounds and the potential of contamination/adulteration, quality control of Cordyceps or Cordyceps-based dietary supplements is critical to ensure its safety and efficacy. This review highlights the recent advances in profiling the bioactive compounds from Cordyceps sinensis, their pharmacological properties, and quality control of this supplement. © 2013 Elsevier B.V. All rights reserved.