Herbal teas are generally considered safe because they are not concentrated. Sensitive people can be allergic, however. For example, people who are allergic to asters, chrysanthemums, ragweed, or yarrow can react to chamomile.
Some plants that were once considered edible are now considered toxic, including comfrey, wormwood, pennyroyal, tansy, and sassafras. These plants should not be ingested.
The information in this bulletin is not intended as advice regarding potential medicinal, therapeutic, or other effects of plants and is for informational and study purposes only. Historical uses mentioned for the herbs are not to be considered substitutes for professional medical advice. It is strongly advised that you educate yourself on plant usage and keep current as new information continues to emerge, which may contradict old studies and beliefs.