Side Effects of Essiac

[Are there any] side effects from using essiac?

"Essiac?" is the trademark name for a herbal blend that has anti-tumour properties and is used for cancer. I am sorry but I am not able to comment on another company's products.
There is an excellent book on Essiac, called "Essence of Essiac", which is available for purchase from Richters.
However, if you are experiencing negative side effects from any product, it is important that you speak to your healthcare provider right away where you may be advised to discontinue it's use.