Rene Caisse, the Canadian nurse credited with the initial widespread use of this tea, stated that the most important herb in the essiac formula was the sheep sorrel.
Furthermore, she made it clear that the sheep sorrel cannot be just the leaves. The sheep sorrel must contain the root, and at the right proporition, that is 20% root of the entire sheep sorrel plant. If the essiac doesn't contain the sheep sorrel with the root, the tea won't be nearly as effective.
The problem is, many herb farms will not sell sheep sorrel with the root included. We were able to obtain sheep sorrel with the root by contracting with a private grower so that we can offer you the best essiac available.