Provides artemisinin, or Qinghaosu, which is the active constituent of the herb Sweet Wormwood (Artemisia annua). Good quality Artemisia annua contains 0.3-0.5% artemisinin, so this pure extract provides hundreds of times more of the active constituent artemisinin than the whole herb itself. Allergy Research Group® introduced artemisinin to the U.S. market more than three decades ago. Independent cell tests have verified its effectiveness, and independent potency tests are conducted on every batch using HPLC. Allergy Research Group® artemisinin is minimum 98.5% pure and does not contain thujone.