Regrettably, the answer is yes. Individuals suffering from clinical depression should avoid this product. The safety of using kava during pregnancy or lactation has also not been established. Kava can cause allergic reactions in some people. A German agency recommends that the product should not be used continuously for more than three months.
Continual use can lead to a drying and yellowing of the skin.
It is believed that kava may interfere with the assimilation of some of the B vitamins. The recommended dosage of kava is 60 to 120 mg, but it has been used in dosages of up to 300 mg of the kava pyrones per day. Doses in one study were 70 mg kava pyrones three times a day. I couldn't find any documented drug interactions. Theoretically, this product should be used with caution with concurrent use of sedatives, alcohol, hypnotics, anti-convulsants, tranquilizers and depression therapies.