I read a book that a doctor wrote after he studied the olive leaf in 1995 and found that it is "an effective antimicrobial agent against 137 diseases "including AIDS and ANTHRAX because the chemical OLEUROPEIN supercharges the immune system (don't have the book anymore). For centuries, in Mediteranean countries, when people got sick, they would chew on an olive leaf. I got the book at a vitamin store called "The Vitamin Shoppe for $6.95 and the Olive leaf extract pills averaged to about 60 cents a day (probably won't be hard to find). There is a die-off effect, so flush with water. I also heard that Samento is VERY powerful in boosting the immune system and costs just about the same.