Rene M. Caisse was fastidious about the proper preparation of Essiac. In 1977, thirty years after Rene retired, she finally entrusted the formula to then Lieutenant Governor Pauline McGibbon. A year before her death on December 26, 1978, Rene gave the recipe to the Toronto-based Resperin Company.  

Mary McPherson was well acquainted with Rene and assisted her in the Cancer Clinic from 1935 to 1978. During the later years of Rene's practice, Mary was responsible for the preparation of the Essiac under Rene's supervision. In a sworn affidavit made on December 23, 1994, Mary wrote down her friend’s recipe and entrusted it to the Town of Bracebridge for safe keeping.  

6 ½ cups cut up Burdock Root
1 pound powdered Sheep Sorrel
¼ cup powdered Slippery Elm Bark
1 ounce powdered Turkish Rhubarb Root

Rhubarb

Slippery Elm Bark Burdock

Sheep Sorrel

• Mix the ingredients thoroughly and store in a glass jar in a dark dry cupboard.

• Measure 1 ounce of the herb mixture and mix with 21 ounces of water.

• Cover and boil hard for 10 minutes.

• Turn off the heat but leave the covered pot sitting on a warm plate overnight.

• In the morning, heat to steaming hot and let settle for a few minutes.

• Filter through a fine strainer into hot, sterilized bottles.

• Store in a dark, cool cupboard.

• Refrigerate after opening.