ESSIAC ® is a world renowned herbal formula developed by Rene M. Caisse, a Canadian nurse. Since 1922, Nurse Caisse used her original herbal formula to help support the immune system.* Rene Caisse is world renowned for making significant contributions to the field of natural medicine. The herbs in ESSIAC® are grown specifically for Essiac Canada International which are harvested at peak times in order to ensure maximum botanical potency. ESSIAC® is approved by Health Canada and is shipped worldwide.