Though the root is rarely used for medicine, it is extremely powerful, especially for hot, sore infections of the throat and lungs. It numbs pain from infection in the throat and bronchial tubes and is exceptionally cooling to the throat and lungs. It is also highly antibacterial, being exceptionally effective topically. The leaf of above-ground plant is generally used for malaria, for intestinal worms, as a liver and digestive tonic, and for colds and flu. Water infusions of the leaf have been shown to produce 89 percent inhibition of malaria at 1 part in 35. Regular use as a tea as a preventative was found to prevent acetaminophen-induced liver disease in mice and rats. Some herbalists do not recommend the use of this herb because of its thujone content. However, it is one of the most powerful herbs for the treatment of antibiotic-resistant disease available. Millennia of traditional use support its continued place in the herbal dispensatory.
Inevitably, medical researchers have insisted on isolating a chemical component of wormwood, called artemesinin, for use in treating malaria. Artemesinin has been further processed into a specific drug, artemether. Clinical trials have shown that artemether is as effective as quinine in treating both resistant and nonresistant strains of malaria; trials in Gambia and Vietnam showed similar results. In the Vietnamese study, malarial symptoms cleared in 30 hours with artemether, 33 hours with quinine. Parasite clearance was markedly shorter with artemether in all trails; in the Vietnamese study it was 48 hours, versus 60 hours with quinine. However, patients given artemether experience several unpleasant side effects from the drug (as is often the case with pharmaceuticals). As with all searches for “active constituents” there is some question about its necessity. Taiwanese researchers have found the whole herb to be as effective with fewer side effects than the isolated component. Furthermore, extracts of Artemisia annua that contained no artemesinin were just as effective an antimalarial (though at twice the dosage for artemesinin).
Wormwood is excellent to expel intestinal worms, stimulate the appetite and liver, and also the uterus. Two of its phytochemicals stimulate digestion and the extract improves liver and gallbladder function in people with liver disease. It is also an effective external antiseptic. Compresses soaked in wormwood tea are recommended for irritations, bruises, and sprains.