http://articles.mercola.com/sites/articles/archive/2001/07/04/hrt2.aspxPart 2 of 5 ( Part 1 , Part 3 , Part 4 , Part 5 ) Tim O'Shea What Is Progesterone, Anyway? Progesterone is the other primary female hormone. It is produced in the ovaries. It is the precursor for both estrogen and testosterone, as well as all other naturalenCommunityServer 2008.5 SP1 (Build: 31106.3070)