Best artemisinin contains high quality artemisinin or ching-hao-su, an extract from the traditional chinese herb artemisia annua (sweet wormwood) or ching-hao. sweet wormwood leaves have been consumed over several centuries for promoting general health. the extract artemisinin has been used for several decades.best artemisinin is encapsulated in the u.s. with the artemisinin by holley pharmaceuticals, a worldwide leader in high quality artemisinin research and production for 30 years, and is extracted from plants grown and harvested in accordance with gap (good agricultural practice) standards. the extract itself is manufactured to the highest pharmaceutical-grade quality specifications in a certified gmp (good manufacturing practice) facility, ensuring the highest potency.