Goat's Rue, Ruta graveolens Cautions

Your website states the U.S. prohibits goat's rue seed from coming into this country. Do you know why? Is it highly invasive or something? I'd really like to grow it for myself - it would be a lot cheaper than buying the dried and crushed herb in capsule form.

People reactions to goat's rue unfortunately varies greatly. Most have no problem with it when used according to directions. However some people do not find this plant benign: Caution should be taken with using rue topically. Applied to the skin with sun exposure, the oil and leaves can cause blistering. Rue oil can cause severe stomach pain, vomiting and convulsions and may be fatal to sensitive individuals.