Doctor s 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.* Doctor s Best Artemisinin is made in the U.S. with pharmaceutical grade Artemisinin to ensure high potency.*