Heterocyclic organic compounds are composed of at least one atom of carbon bound to at least one other element, such as oxygen or sulfur. The atoms are arranged in a ring structure. Hexamine goes by several other names, including methenamine, urotropine, and hexamethylenetetramine. Among other applications, hexamine is used as an antibiotic.

The reaction of formaldehyde and ammonia yields the crystalline hexamine. Its molecular formula is C6H12N4. Particles of hexamine tend to range in size from 80 to 800 micrometers; a strand of human hair is about 100 micrometers wide. It is soluble in water and in most organic substances, and it has a cage-like structure.