I took Aldactone for several years. Feb. 2008, my OB/GYN found a cyst on my left ovary (after I had a period at age 62). I asked to go to an endocrinologist for a consultation, and after he asked me several questions about what I could be eating to have extra estrogen, he stated that Aldactone can cause excess breast tissue in men and ovarian cysts in women. The aldactone also caused my beast to be tight and full and I had not idea where that was coming from. After I stopped the Aldactone, the fullness in my breasts went away.