The use of herbs is a time honored approach to strengthening the body and treating disease. However, herbs contain active substances that may trigger side effects and interact with other herbs, supplements, or medications. For these reasons, people should take herbs under the supervision of a practitioner knowledgeable in the field of botanical medicine.
People with tuberculosis, leukemia, diabetes, connective tissue disorders, multiple sclerosis, HIV or AIDS, any autoimmune diseases, or, possibly, liver disorders should not take echinacea. There is some concern that echinacea may reduce the effectiveness of medications that suppress the immune system. For this reason, people receiving organ transplants who must take immunosuppressant medications should avoid this herb. .