Longer-term use (over four weeks) or intake of amounts higher than those recommended can cause nausea, vomiting, insomnia, restlessness, vertigo, tremors, and seizures.¹² Thujone-containing oil or alcoholic beverages (absinthe) made with the oil is strictly inadvisable—the oil is addictive and may cause brain damage, seizures, and even death.¹³ Short-term use (two to four weeks) of a wormwood tea or tincture has not resulted in any reports of significant side effects. One study found there were no side effects when using less than 1 ml tincture three times per day for as long as nine months to promote digestive function.¹⁴ Nevertheless, consult with a healthcare professional knowledgeable in herbal medicine before taking wormwood. Wormwood is not recommended during pregnancy and breast-feeding.¹³