Native uses in Polynesia-rhizomes are chewed then fermented.

Notes: Energetics: Pungent, bitter, neutral, dry; Meridians: Kidney, Spleen, Bladder

Traditional: ceremonial intoxicating drink; induce relaxation, weight reduction,, treats fungal infection, asthma, colds, cystitis, gonorrhea, headache, menstrual irregularities, urinary infections, and warts. Kings: “neuralgia, particularly of the trifacial nerve, toothache; earache; ocular pain; reflex neuralgia; anorexia; dizziness and despondency; gonorrhea; chronic catarrhal inflammation; vesical irritation ; painful micturition; dysuria.” Fyfe wrote: “acts upon the stomach much like the bitter tonics, and markedly increases the appetite. It acts directly upon mucous membranes, quickly restoring their tone. It is one of our best stomachic tonics, and greatly improves digestion and assimilation. In chronic diarrhea it constitutes a useful medicament, and is especially valuable in cases characterized by large catarrhal discharges and associated with an atonic condition of the entire digestive tract; specific action on kidney, in medium dose, it will speedily produce an abundant secretion of limpid urine, which is readily passed. In acute gonorrhea, it is employed with gratifying results…it is employed in gleet with satisfactory results and in leucorrhea it often aids. It is tonic stimulant, sialagogue and diuretic. In Large doses produce an intoxication of a reserved and drowsy nature. Felter adds; “The patient is pale, the urinary product inconstant in quality; the tissues, especially of feet and legs, are edematous; patient is indisposed to exertion, Piper methysticum augments digestion and promotes better assimilation. The glandular activity of the digestive tract is increased, natural secretion and excretion favored, constipation is overcome, and hemorrhoids, if present, are reduced. It also exerts a marked curative influence in chronic intestinal catarrh. In addition to the Genito-urinary effects, which work presumable by decreasing the blood supply by contracting the capillaries; it is of some value in acute vaginitis, chronic bronchitis, rheumatism, and dropsy due to renal inefficiency; remedy for neuralgic pain; neuralgia of the stomach and intestines, and neuralgic and spasmodic dysmenorrhea; abdominal neurosis due to prostatic, urethral or testicular diseases or pectoral neuralgia arising reflexly from nervous dyspepsia.

Holmes: urinary remedy with a relaxant, restorative and stimulant action; useful with any condition of pain on urination.

Published research: successful for treating anxiety; sedation is not mediated through the GABA receptor complex.

Recent research: protects against oxidative stress-induced neuronal cell death through activation of the Nrf2 signaling; in microglial cells, kava strongly inhibited LPS-stimulated iNOS induction and NO production; exerts potent and dose-dependent analgesic activity, inhibiting abdominal constrictions; increases female sexual drives; anti-cancer activities, in a dose-dependent inhibition of cell viability, inhibition of NF-κB, activation of caspases, and activation of extracellular signal regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK); ERK1/2 and JNK are mitogen activated protein kinases that play central roles in regulating cell fate; kava may reduce colon cancer risk; be a potential therapeutic agent in the treatment of Uterine Leimyomas; kava root extract reduces tumor growth; has a pro-apoptotic effect on synovial sarcomas and inhibits the growth of synovial sarcomas; prevents and treats adenoid cystic carcinoma; suppresses tumor genesis, reduces tumor growth in hormonal refractory prostate cancer; intervenes in NF-κB-dependent pathological conditions such as inflammation; and has strong antitrypanosomal effects