Some plants contain phytochemicals that have effects on the body. There may be some effects when consumed in the small levels that typify culinary "spicing", and some herbs are toxic in larger quantities. Herbal extract of Piper methysticum can be used for medical purposes to relieve depression and stress. Certain herbs contain psychoactive properties that have been used for both religious and recreational purposes by humans notably the leaves and extracts of the cannabis and coca plants.
