From pyroclastic compounds to natural hormones and common drugs, this site features detailed chemical information on various molecular compounds. Each month a new molecule is added to the list. Molecule pages connect to either a University Chemistry Department or commercial site in the United Kingdom, the United States, or anywhere in the world. Most descriptions include a history of use, chemical structure, properties, reactivity, and current research and development regarding the respective molecule. Site visitors are encouraged to contribute a molecule description. Many links are offered to contributor institutions and related Molecule of the Month collections.