Piper methysticum

Specific Indications. - Irritation, inflammation, or debility of the urinary passages; chronic catarrhal inflammations; vesical irritation and inflammation; vesical atony; painful micturition, strangury, and dysuria; gonorrhea, slow and intractable.

Action and Therapy. - Large doses will cause a drowsy and reserved intoxication, with confused dreams. The taste being agreeable, it is said one easily becomes a proselyte to its seductive qualities. The intoxicating drink prepared from it by the natives of certain Pacific islands induces an intoxication of a reserved drowsy character attended with confused dreams. Its long-continued use by them has caused more or less obscuration of vision and a dry, cracked, scaly and ulcerated skin, and lesions closely allied to leprosy.

The Eclectic Materia Medica, Pharmacology and Therapeutics by Harvey Wickes Felter, M.D. (1922)

What the Science Says

Although scientific studies provide some evidence that kava may be beneficial for the management of anxiety, the U.S. Food and Drug Administration (FDA) has issued a warning that using kava supplements has been linked to a risk of severe liver damage.

Kava is not a proven therapy for other uses.

NCCAM-funded studies on kava were suspended after the FDA issued its warning.