Methacycline is a semi-synthetic tetracycline prepared by dehydration of the 6-hydroxy group of oxytetracycline to yield an exocyclic 6-methylene. Like all tetracyclines, methacycline shows broad spectrum antibacterial and antiprotozoan activity and acts by binding to the 30S and 50S ribosomal subunits, blocking protein synthesis. Methacycline has been extensively cited in the literature with over 400 references.